The weeds are winning

On a languid, damp July morning, I meet weed scientist Aaron Hager outside the old Agronomy Seed House at the University of Illinois’ South Farm. In the distance are round barns built in the early 1900s, designed to withstand Midwestern windstorms. The sky is a formless white. It’s the day after a storm system hundreds of miles wide rolled through, churning out 80-mile-per-hour gusts and prompting dozens of tornado watches and sirens reminiscent of a Cold War bomb drill.

On about 23 million acres, or roughly two-thirds of the state, farmers grow corn and soybeans, with a smattering of wheat. They generally spray virtually every acre with herbicides, says Hager, who was raised on a farm in Illinois. But these chemicals, which allow one plant species to live unbothered across inconceivably vast spaces, are no longer stopping all the weeds from growing.

Since the 1980s, more and more plants have evolved to become immune to the biochemical mechanisms that herbicides leverage to kill them. This herbicidal resistance threatens to decrease yields—out-of-control weeds can reduce them by 50% or more, and extreme cases can wipe out whole fields. 

At worst, it can even drive farmers out of business. It’s the agricultural equivalent of antibiotic resistance, and it keeps getting worse.

As we drive east from the campus in Champaign-Urbana, the twin cities where I grew up, we spot a soybean field overgrown with dark-green, spiky plants that rise to chest height. 

“So here’s the problem,” Hager says. “That’s all water hemp right there. My guess is it’s been sprayed at least once, if not more than once.”

“With these herbicide-resistant weeds, it’s only going to get worse. It’s going to blow up.”

Water hemp (Amaranthus tuberculatus), which can infest just about any kind of crop field, grows an inch or more a day, and females of the species can easily produce hundreds of thousands of seeds. Native to the Midwest, it has burst forth in much greater abundance over the last few years, because it has become resistant to seven different classes of herbicides. Season-long competition from water hemp can reduce soybean yields by 44% and corn yields by 15%, according to Purdue University Extension.

Most farmers are still making do. Two different groups of herbicides still usually work against water hemp. But cases of resistance to both are cropping up more and more.

“We’re starting to see failures,” says Kevin Bradley, a plant scientist at the University of Missouri who studies weed management. “We could be in a dangerous situation, for sure.”

Elsewhere, the situation is even more grim.

“We really need a fundamental change in weed control, and we need it quick, ’cause the weeds have caught up to us,” says Larry Steckel, a professor of plant sciences at the University of Tennessee. “It’s come to a pretty critical point.” 

On the rise

According to Ian Heap, a weed scientist who runs the International Herbicide-Resistant Weed Database, there have been well over 500 unique cases of the phenomenon in 273 weed species and counting. Weeds have evolved resistance to 168 different herbicides and 21 of the 31 known “modes of action,” which means the specific biochemical target or pathway a chemical is designed to disrupt. Some modes of action are shared by many herbicides.

One of the most wicked weeds in the South, one that plagues Steckel and his colleagues, is a rhubarb-red-stemmed cousin to water hemp known as Palmer amaranth (Amaranthus palmeri). Populations of the weeds have been found that are impervious to nine different classes of herbicides. The plant can grow more than two inches a day to reach eight feet in height and dominate entire fields. Originally from the desert Southwest, it boasts a sturdy root system and can withstand droughts. If rainy weather or your daughter’s wedding prevents you from spraying it for a couple of days, you’ve probably missed your chance to control it chemically.  

Palmer amaranth “will zero your yield out,” Hager says.

Several other weeds, including Italian ryegrass and a tumbleweed called kochia, are inflicting real pain on the farmers in the South and the West, particularly in wheat and sugar beet fields.   

Chemical birth 

Before World War II, farmers generally used cultivators such as plows and harrows to remove weeds and break up the ground. Or they did it by hand—like my mother, who remembers hoeing weeds in cornfields as a kid growing up on an Indiana farm.

That changed with the advent of synthetic pesticides and herbicides, which farmers started using in the 1950s. By the 1970s, some of the first examples of resistance appeared. By the early 1980s, Heap and his colleague Stephen Powles had discovered populations of ryegrass (Lolium rigidum) that were resistant to the most commonly used herbicides, known as ACCase inhibitors, spreading throughout southern Australia. Within a few years, this species had become resistant to yet another class, called ALS-inhibiting herbicides.  

The problem had just begun. It was about to get much worse.

In the mid to late 1990s, the agricultural giant Monsanto—now a part of Bayer Crop Science—began marketing genetically engineered crops including corn and soybeans that were resistant to the commercial weed killer Roundup, the active ingredient of which is called glyphosate. Monsanto portrayed these “Roundup-ready” crops, and the ability to spray whole fields with glyphosate, as a virtual silver bullet for weed control.

Glyphosate quickly became one of the most widely used agricultural chemicals, and it remains so today. It was so successful, in fact, that research and development on other new herbicides withered: No major commercial herbicide appears likely to hit the market anytime soon that could help address herbicide resistance on a grand scale. 

Monsanto claimed it was “highly unlikely” that glyphosate-resistant weeds would become a problem. There were, of course, those who correctly predicted that such a thing was inevitable—among them Jonathan Gressel, a professor emeritus at the Weizmann Institute of Science in Rehovot, Israel, who has been studying herbicides since the 1960s.

Stanley Culpepper, a weed scientist at the University of Georgia, confirmed the first case of Roundup resistance in Palmer amaranth in 2004. Resistance rapidly spread. Both Palmer amaranth and water hemp produce male and female plants, the former of which produce pollen that can blow long distances on the wind to pollinate the latter. This also gives the plant a lot of genetic diversity, which allows it to evolve faster—all the better for herbicide resistance to develop and spread. These super-weeds sowed chaos throughout the state.

“It devastated us,” Culpepper says, recalling the period from 2008 to 2012 as particularly difficult. “We were mowing fields down.”  

Staying alive

Herbicide resistance is a predictable ­outcome of evolution, explains Patrick Tranel, a leader in the field of molecular weed science at the University of Illinois, whose lab is a few miles from the South Farm. 

“When you try to kill something, what does it do? It tries to not be killed,” Tranel says. 

Weeds have developed surprising ways to get around chemical control. One 2009 study published in the Proceedings of the National Academy of Sciences showed that a mutation in the Palmer amaranth genome allowed the plant to make more than 150 copies of the gene that glyphosate targets. That kind of gene amplification had never been reported in plants before, says Franck Dayan, a weed scientist at Colorado State University.

Another bizarre way resistance can arise in that species is via structures called extrachromosomal circular DNA, strands of genetic material including the gene target for glyphosate that exist outside of nuclear chromosomes. This gene can be transferred via wind-blown pollen from plants with this adaptation. 

But scientists are increasingly finding metabolic resistance in weeds, where plants have evolved mechanisms to break down just about any foreign substance—including a range of herbicides. 

Let’s say a given herbicide worked on a population of water hemp one year. If any plants “escape,” or survive, and make seeds, their offspring could possess metabolic resistance to the herbicides used. 

“When you try to kill something, what does it do? It tries to not be killed.”

Patrick Tranel, University of Illinois

There’s evidence of resistance developing to both of the chemical groups that have replaced or been mixed with Roundup to kill this weed: an herbicide called glufosinate and a pair of substances known as 2,4-D and dicamba. These two would normally kill many crops, too, but there are now millions of acres of corn and soy genetically modified to be impervious. So essentially the response has been to throw more chemicals at the problem.

“If it worked last year, if you have metabolic resistance there’s no guarantee it’s going to work this year,” Hager says. 

Many of these herbicides can harm the environment and have the potential to harm human health, says Nathan Donley, the environmental health science director at the Center for Biological Diversity, which is based in Tucson, Arizona. Paraquat, for example, is a neurotoxic chemical banned in more than 60 countries (it’s been linked to conditions like Parkinson’s), Donley says, but it’s being used more and more in the United States. 2,4-D, one of the active ingredients in Agent Orange, is a potential endocrine disruptor, and exposure to it is correlated with increased risk of various cancers. Glyphosate is listed as a probable human carcinogen by an agency within the World Health Organization and has been the subject of tens of thousands of lawsuits worth tens of billions. Atrazine can stick around in groundwater for years and can shrink testicles and reduce sperm count in certain fish, amphibians, reptiles, and mammals.

Replacing glyphosate with herbicides like 2,4-D and dicamba, which are generally more toxic, “is definitely a step in the wrong direction,” Donley says. 

Looking for solutions

It’s not just chemicals. Weeds can become resistant to any type of control method. In a classic example from China, a weed called barnyard grass evolved over centuries to resemble rice and thus evade hand weeding.

Because weeds can evolve relatively quickly, researchers recommend a wide diversity of control tactics. Mixing two herbicides with different modes of action can sometimes work, though that’s not the best for the environment or the farmer’s wallet, Tranel says. Rotating the plants that are grown helps, as does installing winter cover crops and, above all, not using the same herbicide in the same way every year. 

Fundamentally, the solution is to “not focus solely on herbicides for weed management,” says Micheal Owen, a weed scientist and emeritus professor at Iowa State University. And that presents a “major, major issue for the farmer” and the current state of American farms, he adds. 

weeds

BELL HUTLEY

Farms have ballooned in size over the last couple of decades, as a result of rural flight, labor costs, and the advent of chemicals and genetically modified crops that allowed farmers to quickly apply herbicides over massive areas to control weeds. This has led to a kind of sinister simplification in terms of crop diversity, weed control practices, and the like. And the weeds have adjusted. 

On the one hand, it’s understandable that farmers often do the cheapest thing they can to control weeds, to get them through the year. But resistance is a medium- to long-term problem running up against a system of short-term thinking and incentives, says Katie Dentzman, a rural sociologist also at Iowa State University.

Her studies have shown that farmers are generally informed and worried about herbicide resistance but are constrained by a variety of factors that prevent them from really heading it off. The farm is too big to economically control weeds without spraying in a single shot, some farmers say, while others lack the labor, financing, or time. 

Agriculture needs to embrace a diversity of weed control practices, Owen says. But that’s much easier said than done. 

“We’re too narrow-visioned, focusing on herbicides as the solution,” says Steven Fennimore, a weed scientist with the University of California, Davis, based in Salinas, California.

Fennimore specializes in vegetables, for which there are few herbicide options, and there are fewer still for organic growers. So innovation is necessary. He developed a prototype that injects steam into the ground, killing weeds within several inches of the entry point. This has proved around 90% effective, and he’s used it in fields growing lettuce, carrots, and onions. But it is not exactly quick: It takes two or three days to treat a 10-acre block.

Many other nonchemical means of control are gaining traction in vegetables and other high-value crops. Eventually, if the economics and logistics work out, these could catch on in row crops, those planted in rows that can be tilled by machinery. 

A company called Carbon Robotics, for example, produces an AI-driven system called the LaserWeeder that, as the name implies, uses lasers to kill weeds. It is designed to pilot itself up and down crop rows, recognizing unwanted plants and vaporizing them with one of its 30 lasers. LaserWeeders are now active in at least 17 states, according to the company.  

You can also shock weeds by using electricity, and several apparatuses designed to do so are commercially available in the United States and Europe. A typical design involves the use of a height-adjustable copper boom that zaps weeds it touches. The most obvious downside with this method is that the weeds usually have to be taller than the crop. By the time the weeds have grown that high, they’ve probably already caused a decline in yield. 

Weed seed destructors are another promising option. These devices, commonly used in Australia and catching on a bit in places like the Pacific Northwest, grind up and kill the seeds of weeds as wheat is harvested.

An Israeli company called WeedOut hatched a system to irradiate and sterilize the pollen of Palmer amaranth plants and then release it into fields. This way, female plants receive the sterile pollen and fail to produce viable seeds. 

“I’m very excited about this [as] a long-term way to reduce the seed bank and to manage these weeds without having to spray an herbicide,” Owen says. 

WeedOut is currently testing its approach in corn, soybean, and sugar beet fields in the US and working to get EPA approval. It recently secured $8 million in funding to scale up. 

In general, AI-driven rigs and precision spraying are very likely to eventually reduce herbicide use, says Stephen Duke, who studies herbicides at the University of Mississippi: “Eventually I expect we’ll see robotic weeding and AI-driven spray rigs taking over.” But he expects that to take a while on crops like soybeans and corn, since it is economically difficult to invest a lot of money in tending such “low-value” agronomic crops planted across such vast areas.

A handful of startups are pursuing new types of herbicides, based on natural products found in fungi or used by plants to compete with one another. But none of these promise to be ready for market anytime soon.

Field day 

Some of the most successful tools for preventing resistance are not exactly high-tech. That much is clear from the presentations at the Aurora Farm Field Day, organized by Cornell University just north of its campus in Ithaca, New York. 

For example, one of the most important things farmers can do to prevent the spread of weed seeds is to clean out their combines after harvest, especially if they’re buying or using equipment from another state, says Lynn Sosnoskie, an assistant professor and weed scientist at Cornell. 

Combines are believed to have already introduced Palmer amaranth into the state, she says—there are now at least five populations in New York. 

Another classic approach is crop rotation—switching between crops with different life cycles, management practices, and growth patterns is a mainstay of agriculture, and it helps prevent weeds from becoming accustomed to one cropping system. Yet another option is to put in a winter cover crop that helps prevent weeds from getting established. 

“We’re not going to solve weed problems with chemicals alone,” Sosnoskie says. That means we have to start pursuing these kinds of straightforward practices.

It’s an especially important point to hammer home in places like New York state, where the problem isn’t yet top of mind. That’s in part because the state isn’t dominated by monocultures the way the Midwest is, and it has a more diverse patchwork of land use. 

But it’s not immune to the issue. Resistance has arrived and threatens to “blow up,” says Vipan Kumar, also a weed expert at Cornell.

“We have to do everything we can to prevent this,” Kumar says. “My role is to educate people that this is coming, and we have to be ready.”

Douglas Main is a journalist and former senior editor and writer at National Geographic.

How plants could mine metals from the soil

Nickel may not grow on trees—but there’s a chance it could someday be mined using plants. Many plant species naturally soak up metal and concentrate it in their tissues, and new funding will support research on how to use that trait for plant-based mining, or phytomining. 

Seven phytomining projects just received $9.9 million in funding from the US Department of Energy’s Advanced Research Projects Agency for Energy (ARPA-E). The goal is to better understand which plants could help with mining and determine how researchers can tweak them to get our hands on all the critical metals we’ll need in the future.

Metals like nickel, crucial for the lithium-ion batteries used in electric vehicles, are in high demand. But building new mines to meet that demand can be difficult because the mining industry has historically faced community backlash, often over environmental concerns. New mining technologies could help diversify the supply of crucial metals and potentially offer alternatives to traditional mines.  

“Everyone wants to talk about opening a new gigafactory, but no one wants to talk about opening a new mine,” says Philseok Kim, program director at ARPA-E for the phytomining project. The agency saw a need for sustainable, responsible new mining technologies, even if they’re a major departure from what’s currently used in the industry. Phytomining is a prime example. “It’s a crazy idea,” Kim says.

Roughly 750 species of plants are known to be hyperaccumulators, meaning they soak up large amounts of metals and hold them within their tissues, Kim says. The plants, which tend to absorb these metals along with other nutrients in the soil, have adapted to tolerate them.

Of the species known to take in and concentrate metals, more than two-thirds do so with nickel. While nickel is generally toxic to plants at high concentrations, these species have evolved to thrive in nickel-rich soils, which are common in some parts of the world where geologic processes have brought the metal to the surface. 

Even in hyperaccumulators, the overall level of nickel in a plant’s tissues would still be relatively small—something like one milligram of metal for every gram of dried plant material. But burning a dried plant (which largely removes the organic material) can result in ash that’s roughly 25% nickel or even higher.

The sheer number of nickel-tolerant plants, plus the metal’s importance for energy technologies, made it the natural focus for early research, Kim says.

But while plants already have a head start on nickel mining, it wouldn’t be feasible to start commercial operations with them today. The most efficient known hyperaccumulators might be able to produce 50 to 100 kilograms of nickel per hectare of land each year, Kim says. That would yield enough of the metal for just two to four EV batteries, on average, and require more land than a typical soccer field. The research program will aim to boost that yield to at least 250 kilograms per hectare in an attempt to improve the prospects for economical mining.

The seven projects being funded will aim to increase production in several ways. Some of the researchers are hunting for species that accumulate nickel even more efficiently than known species. One candidate is vetiver, a perennial grass that grows deep roots. It’s known to accumulate metals like lead and is often used in cleanup projects, so it could be a good prospect for soaking up other metals like nickel, says Rupali Datta, a biology researcher at Michigan Technological University and head of one of the projects.

Another awardee will examine over 100,000 herbarium samples—preserved and catalogued plant specimens. Using a technique called x-ray fluorescence scanning, the researchers will look for nickel in those plants’ tissues in the hopes of identifying new hyperaccumulator species. 

Other researchers are looking to boost the mining talents of known nickel hyperaccumulators. One problem with many of the established options is that they don’t have very high biomass—in other words, they’re small. So even if the plant has a relatively high concentration of nickel in its tissues, each plant will collect only a small amount of the metal. Researchers want to tweak the known hyperaccumulators to plump them up—for example, by giving them bigger root systems that would allow them to reach deeper into the soil for metal.

Another potential way to improve nickel uptake is to change the plants’ growth cycle. Most perennial plants will basically stop growing once they flower, says Richard Amasino, a biochemistry researcher at the University of Wisconsin–Madison. So one of his goals for the project is figuring out a way to delay flowering in Odontarrhena, a family of plants with bright yellow flowers, so they have more time to soak up nickel before they quit growing for the season.

Researchers are also working with these known target species to make sure they won’t become invasive in the places they’re planted. For example, Odontarrhena are native to Europe, and researchers want to make sure they wouldn’t run wild and disrupt natural ecosystems if they’re brought to the US or other climates where they’d grow well.

Hyperaccumulating plants are already used in mineral exploration, but they likely won’t be able to produce the high volumes of nickel we mine today, Simon Jowitt, director of the Center for Research in Economic Geology at the University of Nevada, Reno, said in an email. But plants might be a feasible solution for dealing with mine waste, he said. 

There’s also the question of what will happen once plants suck up the metals from a given area of soil. According to Jowitt, that layer may need to be removed to access more metal from the lower layers after a crop is planted and harvested. 

In addition to identifying and altering target species, researchers on all these projects need to gain a better understanding where plants might be grown and whether and how natural processes like groundwater movement might replenish target metals in the soil, Kim says. Also, scientists will need to analyze the environmental sustainability of phytomining, he adds. For example, burning plants to produce nickel-rich ash will lead to greenhouse-gas emissions. 

Even so, addressing climate change is all about making and installing things, Kim adds, and we need lots of materials to do that. Phytomining may be able to help in the future. “This is something we believe is possible,” Kim says, “but it’s extremely hard.”

Your future air conditioner might act like a battery

As temperatures climb on hot days, many of us are quick to crank up our fans or air conditioners. These cooling systems can be a major stress on electrical grids, which has inspired some inventors to create versions that can store energy as well as use it. 

Cooling represents 20% of global electricity demand in buildings, a share that’s expected to rise as the planet warms and more of the world turns to cooling technology. During peak demand hours, air conditioners can account for over half the total demand on the grid in some parts of the world today.

New cooling technologies that incorporate energy storage could help by charging themselves when renewable electricity is available and demand is low, and still providing cooling services when the grid is stressed.  

“We say, take the problem, and turn it into a solution,” says Yaron Ben Nun, founder and chief technology officer of Nostromo Energy.

One of Nostromo Energy’s systems, which it calls an IceBrick, is basically a massive ice cube tray. It cools down a solution made of water and glycol that’s used to freeze individual capsules filled with water. One IceBrick can be made up of thousands of these containers, which each hold about a half-gallon, or roughly two liters, of water.

Insulation keeps the capsules frozen until it’s time to use them to help cool down a building. Then the ice is used to drop the temperature of the water-glycol mixture, which in turn cools down the water that circulates in the building’s chilling system. The whole thing is designed to work as an add-on with existing equipment, Ben Nun says. 

Nostromo installed its first system in the US in 2023, at the Beverly Hilton hotel in Los Angeles. It has a capacity of 1.4 megawatt-hours, and it also serves the neighboring Waldorf Astoria. The installation contains 40,000 capsules, amounting to about 150,000 pounds of ice. It usually charges up for 10 to 12 hours, starting at night and finishing around midday. That leaves it ready to discharge its cooling power between the late afternoon and evening, when demand on the grid is high and solar power is dropping off as the sun sets.

Using the IceBrick increases the total electricity needed for cooling, as some energy is lost to inefficiency during the cycle. But the goal is to decrease the energy demand during peak hours, which can cut costs for building owners, Ben Nun says. The company is in the process of securing roughly $300 million in funding, in part from the US Department of Energy’s Loan Programs Office, to fully finance 200 of these systems in California, he adds. 

closeup of the Ice brick system from Nostromo showing pipes with red connectors leading to metal cube shapes
Nostromo’s IceBrick is made of individual capsules that freeze and thaw to store energy.
NOSTROMO

While building owners can benefit immediately from these individual energy storage solutions, the real potential to help the grid comes when systems are linked together, Ben Nun says. 

When the grid is extremely stressed, utility companies are sometimes forced to shut off electricity supply to some areas, leaving people there without power when they need it most. Technologies that can adjust to meet the grid’s needs could help reduce reliance on these rolling blackouts. 

This kind of approach isn’t new—many commercial units have large tanks that hold chilled water or another cooling fluid that can drop the temperature in a building at a moment’s notice. But Nostromo’s technology can store more energy with much less material, because it uses the freezing and melting process rather than just cooling down a liquid, Ben Nun says. 

Startup Blue Frontier has differentiated itself in this space by building cooling systems that use desiccants. These materials can suck up moisture—like the little packets of silica beads that often come with new shoes and bags. But instead of those beads, the company is using a concentrated salt solution.

Blue Frontier’s cooling units pass a stream of air over a thin layer of the desiccant, which pulls moisture out of the air. That dry air is then used in an evaporative cooling process (similar to the way sweat cools your skin).

Desiccant cooling systems can be more efficient than the traditional vapor compression air conditioners on the market today, says Daniel Betts, founder and CEO of Blue Frontier. But the system also benefits from the ability to charge up during certain times and deliver cooling at other times.

The key to the energy storage aspect of desiccant cooling is the recharging: Like sponges, desiccants can only soak up a limited amount of water before they need to be wrung out. Blue Frontier does this by causing some water in the salt solution to evaporate, typically with a heat pump, to make it more concentrated. The recharging system can run constantly, or in bursts that can be timed to match periods when electricity is cheap or when more renewable power is available.

The benefit of these energy storage technologies is that they don’t require people turn their cooling systems down or off to help relieve stress on the grid, Betts says. 

Blue Frontier is testing several systems with customers today and hopes to manufacture larger quantities soon. And while commercial buildings are getting the first installations, Betts says he’s interested in bringing the technology to homes and other buildings too.

One challenge facing the companies working on these incoming technologies is finding a way to store large amounts of energy effectively without adding too much cost, says Ankit Kalanki, a principal in the carbon-free buildings program at the Rocky Mountain Institute, a nonprofit energy think tank. Cooling technologies like air conditioners are already expensive, so future solutions will have to be priced competitively to make it in the market. But given the world’s growing cooling demand, there’s still a significant opportunity for new technologies to help meet those needs, he adds.

Just rethinking air conditioning won’t be enough to meet the massive increase in energy demand for cooling, which could triple between now and 2050. To both do that and cut emissions, we’ll still need significantly more renewable energy capacity as well as gigantic battery installations on the grid. But adding flexibility into air-conditioning systems could help cut the investment needed to get to a zero-carbon grid.

Cooling systems can help us cope with our warming climate, Ben Nun says, but there’s a problem with the current options: “You’ll cool yourself, but you keep on warming the globe.”

How fish-safe hydropower technology could keep more renewables on the grid

Hydropower is the world’s leading source of renewable electricity, generating more power in 2022 than all other renewables combined. But while hydropower is helping clean up our electrical grid, it’s not always a positive force for fish.

Dams that create reservoirs on rivers can change habitats. And for some species, especially those that migrate long distances, hydropower facilities can create dangerous or insurmountable barriers. In some parts of the world, including the US, Canada, and Europe, governments have put protections in place to protect ecosystems from hydropower’s potential harms.

New environmental regulations can leave older facilities facing costly renovations or force them to shutter entirely. That’s a big problem, because pulling hydropower plants off the grid eliminates a flexible, low-emissions power source that can contribute to progress in fighting climate change. New technologies, including fish-safe turbines, could help utilities and regulators come closer to striking a balance between the health of river ecosystems and global climate goals. 

That’s where companies like Natel Energy come in. The company started with two big goals: high performance and fish survival, says Gia Schneider, Natel’s cofounder and chief commercial officer.

The company is making new designs for the turbines that generate electricity in hydropower plants as water rushes through equipment and moves their blades. Conventional turbine blades can move as fast as 30 meters per second, or about 60 to 70 miles per hour, Schneider says. When straight, thin edges are moving that quickly and striking fish, “it’s fairly obvious why that’s not a good outcome,” she says.

Natel’s turbine design focuses on preventing fast-moving equipment from making fatal contact with fish. The blades have a thicker leading edge that pushes water out in front of it, creating a stagnation zone, or “basically an airbag for fish,” Schneider says. The blades are also curved, so even if fish are struck, they don’t take a direct hit.

The company has tested its turbines with a range of species, including American eels, alewife, and rainbow trout. In the case of one recent study with American eels, scientists found that over 99% of eels survived after 48 hours of passing through Natel’s equipment. In comparison, one 2010 study found that just 40% of tagged European eels were able to pass through the turbines of a hydropower plant, though survival depended a lot on the size of both the eel and equipment in question.  

Changing turbine designs won’t help fish survive all power plants: at some of the biggest plants with the tallest dams, rapid changes in water pressure can kill fish. But Schneider says that the company’s technology could be slotted into up to half of the existing US hydropower fleet to make plants more fish-safe.

Hydropower is one of the world’s older renewable energy sources. By 2030, more than 20% of the global fleet’s generating units will be more than 55 years old, according to the International Energy Agency. The average age of a hydropower plant in the US today is roughly 65 years.  

In the US, privately held hydropower plants are licensed by an agency called the Federal Energy Regulatory Commission for a term of up to 50 years. Roughly 17 gigawatts’ worth of hydropower facilities (enough to power 13 million homes) are up for relicensing by 2035, according to the National Hydropower Association.

Since many of those facilities were started up, there have been significant changes to environmental requirements, and some plants may face high costs and difficult engineering work as they try to adhere to new rules and stay in operation. Adding screens to basically filter fish out of the intake for hydropower plants is one potential solution in some cases, but both installation and maintenance of such a system can add significant cost. In these facilities, Natel’s technology represents an alternative, Schneider says.

Natel has installed several projects in Maine, Oregon, and Austria. They all involve relatively small turbines, but the company is on the way to undertaking bigger projects and recently won a bid process with a manufacturing partner to supply a larger turbine that’s three meters in diameter to an existing plant, Schnieder says. The company is also licensing its fish-safe turbine designs to existing manufacturers.

Whether utilities move to adopt fish-safe design could depend on how it affects efficiency, or the amount of energy that can be captured by a given water flow. Natel’s turbine designs will, in some cases, be slightly less efficient than today’s conventional ones, Schneider says, though the difference is marginal, and they likely still represent an improvement over older designs. 

While there’s sometimes a trade-off between fish-safe design and efficiency, that’s not the case with all novel turbines in all cases. A 2019 study from the US Army Corps of Engineers found that one new design improved fish safety while also producing more power.

Slotting new turbines into hydropower plants won’t solve all the environmental challenges associated with the technology, though. For example, the new equipment would only be relevant for downstream migration, like when eels move from freshwater rivers out into the ocean to reproduce. Other solutions would still be needed to allow a path for upstream migration.

Ideally, the best solution for many plants would likely be natural bypasses or ramps, which allow free passage of many species in both directions, says Ana T. Silva, a senior research scientist at the Norwegian Institute for Nature Research. However, because of space requirements, these can’t always be installed or used. 

Natel CTO Abe Schneider holds a large trout used in fish passage testing at the Monroe Hydro Plant in Madras, Oregon.
NATEL

People have been trying to improve fish passage for a long time, says Michael Milstein, a senior public affairs officer at NOAA Fisheries, part of the US National Oceanic and Atmospheric Administration. The solutions in place today include fish ladders, where fish swim or hop up into successively taller pools to pass dams. Other dams are too tall for that, and fish are captured and loaded onto trucks to go around them.

The challenge, Milstein says, is that “every river is different, and every dam is different.” Solutions need to be adapted to each individual situation, he adds; fish-safe turbines would be most important when there’s no bypass and going through a facility is the only option fish have.

The issue of protecting ecosystems and providing safe passage for fish has sparked fierce debates over existing hydropower projects across the western US and around the world. 

Even with the current state-of-the-art technology, “it’s not always possible to provide sufficient passage,” Milstein says. Several dams are currently being removed from the Klamath River in Oregon and Northern California because of the effects on local ecosystems.  The dams drastically changed the river, wiping out habitat for local salmon, steelhead, and lamprey and creating ideal conditions for parasites to decimate fish populations. 

But while hydropower facilities can have negative environmental impacts, climate change can also be extremely harmful to wildlife, Natel’s Schneider points out. If too many hydropower plants are shut down, it could leave a gap that keeps more fossil fuels on the grid, hampering efforts to address climate change.  

Reducing hydropower plants’ impact on local environments could help ensure that more of them can stay online, generating renewable electricity that plays an important role in our electrical grid. “Fish-safe turbines won’t solve everything—there are many, many problems in our rivers,” Schneider says. “But we need to start tackling all of them, so this is one tool.”

These climate tech companies just got $60 million

This article is from The Spark, MIT Technology Review’s weekly climate newsletter. To receive it in your inbox every Wednesday, sign up here.

Some people track sports scores or their favorite artists’ tour set lists. Meanwhile, I’m just waiting to hear which climate tech startups are getting big funding awards from government agencies. It’s basically the same thing. 

Every few years, the US agency that’s often called the “energy moonshot factory” announces such awards for a few companies to help them scale up their technology. (The agency’s official name is the Advanced Research Projects Agency—Energy, or ARPA-E.) The grants are designed to help companies take their tech from the lab or pilot stage and get it out into the world. 

The latest batch of these awards was just announced, totaling over $63 million split between four companies. Let’s dig into the winners and consider what each one’s technology says about their respective corners of climate action. 

Antora Energy: Heat batteries for industry

Let’s start with the company you’re most likely to know if you follow this newsletter: Antora Energy. The California-based company is building thermal batteries for use in heavy industry. I covered the company and its first pilot project last year, and thermal batteries were the readers’ choice winner on our list of Breakthrough Technologies this year. 

In case you need a quick refresher, the basic idea behind Antora’s technology is to store energy from cheap, clean wind and solar power in the form of heat, and then use that heat in industrial facilities. It’s an elegant solution to the problem that renewables are available only sometimes, while industry needs clean energy all the time if it wants to cut its carbon emissions, which amount to a whopping 30% of the global total. 

Antora was awarded $14.5 million to scale its technology. One thing the company hopes to achieve with the cash influx is progress on its second product, which delivers not only heat but also electricity. 

Queens Carbon: Lower-emissions cement

Cement is a climate villain hiding in plain sight, as I’ve covered in this newsletter before. Producing the gray slabs that scaffold our world accounts for about 7% of global emissions. 

The challenge in cleaning up the process lies, at least in part, in the fact that lava-hot temperatures are required to kick off the chemical reactions that make cement—I’m talking over 1,500 °C (2,700 °F). 

Queens Carbon developed a new process that cuts down the temperature needed to under 540 °C (1,000 °F). Still toasty, but easier to reach efficiently and with electricity, the company’s CEO, CTO, and cofounder Daniel Kopp said on a press call about the awards. Ideally, that electricity will be supplied with renewables, which could mean big emissions savings.

Queens Carbon will also pocket $14.5 million, and the funding should help with the construction of a pilot plant currently being built in partnership with a major cement producer, Kopp said on the press call. The company plans to scale up to a full-size plant in late 2028 or 2029. 

Ion Storage Systems: Next-generation batteries for EVs

The world is always clamoring for better batteries, and Maryland-based Ion Storage Systems wants to deliver with its solid-state lithium-metal technology.

We named lithium-metal batteries one of our 10 Breakthrough Technologies in 2021. The chemistry could deliver higher energy density, meaning longer range in EVs. 

Ion Storage Systems is planning to produce its batteries first for military customers. With the funding ($20 million worth), the company may be able to get its tech ready for larger-scale production for the wider customer base of the electric-vehicle market. 

I was really interested to hear about the emphasis on manufacturing from CTO Greg Hitz on the press call, as scaling up manufacturing has been a major challenge for other companies trying to build solid-state batteries. Hitz also said that the company’s batteries don’t need to be squeezed at high pressure within cells or heated up, and they can be more simply integrated into battery packs. 

AeroShield Materials: High-tech insulation for more efficient buildings

Last but certainly not least is AeroShield Materials. Between 30% and 40% of energy we put into our buildings for heat and cooling is lost through windows and doors—that’s about $40 billion per year for residential buildings, said Elise Strobach, the company’s CEO and cofounder, on the press call. 

AeroShield is making materials called aerogels that are clear, lightweight, and fire resistant. They can help make windows 65% more energy efficient, Strobach says. 

Insulation isn’t always the most exciting topic, but efficiency is one of the best ways to cut down the need for more energy and provide a straightforward way to slash emissions. AeroShield is starting with windows and doors but plans to explore other projects like retrofitting windows and producing insulation for freezer and refrigerator doors, Strobach said on the call. The $14.5 million award will help build a pilot manufacturing facility. 

These projects cover a huge range of businesses, from transportation and buildings to heavy industry. The one thing they have in common? All urgently need to clean up their act if the world is going to address climate change. Each of these awards is a big vote of confidence from an agency that’s had a lot of experience in energy technology—but what really matters is what these companies do with the money now. 


Now read the rest of The Spark

Related reading

I spoke with ARPA-E director Evelyn Wang last year about how the agency hopes to shape the future of energy technology. 

To see why readers chose thermal batteries as the 11th Breakthrough Technology, check out this story from April.

Cement is one of climate’s hardest problems, as I covered in a feature story about startup Sublime Systems earlier this year.

collage of cloudy skies with money and a control panel of knobs and indicators

STEPHANIE ARNETT/MIT TECHNOLOGY REVIEW | ENVATO

Another thing

There’s a growing pool of money for scientists exploring whether we can reflect away more sunlight to ease warming caused by climate change. 

Quadrature Climate Foundation is among the organizations providing millions of dollars for research into solar geoengineering. This sort of funding can help scientists pursue lab work, modeling, and maybe even outdoor experiments that could improve our understanding of the often controversial field. 

For more on where the money is coming from and how this might affect our efforts to address climate change, check out my colleague James Temple’s story here

One more issue

We often talk about tech that’s serious business—but technology also has a huge effect on how we have fun. That’s the idea behind our latest print edition, the Play issue

For the issue, I wrote about board games that take on the topic of climate change. Are they accurate about the challenge ahead, and crucially, can they be fun? Check out my take here. (For a more in-depth look at one particular game, a new climate-themed Catan, give this newsletter a read.) 

I’d also highly recommend this feature from my colleague Eileen Guo, who looked into the growing business of surf pools—facilities that bring a usually ocean-based activity onto land. She gave one a spin, and considered how these spots affect places facing water scarcity. 

The whole issue is great—find all the stories here

Keeping up with climate  

A new startup will take sodium sulfate, a waste material from manufacturing lithium-ion batteries, and turn it into chemicals that can go into new batteries. Aepnus Technology calls its approach a “fully circular” one. (Heatmap)

Solugen just scored a loan worth over $200 million from the US Department of Energy. The company uses biology to make chemicals used in industries from agriculture to concrete. (C&EN News)

Some Olympic teams, including the delegation from the US, plan to bring their own air conditioners to the Paris games this summer. It could be a big setback for the event’s climate goals. (Associated Press)

Advanced recycling promises an almost miraculous solution to our plastics crisis, but a close look at the industry reveals some problems. Very little plastic is made with these methods, and the industry is selling them on the basis of some tricky accounting. (ProPublica)

You may not know the name Yet-Ming Chiang, but you’ve probably heard of some of the companies he’s had a hand in starting, including Sublime Systems and Form Energy. Learn more about this MIT professor and serial entrepreneur here. (Cipher)

Running Tide had grand plans to suck carbon dioxide out of the atmosphere with the help of the ocean. Now, the startup is shutting down. Here’s what the company’s implosion means for carbon removal’s future. (Latitude Media)

→ The company was in some rocky waters a couple of years ago, as my colleague James Temple revealed at the time. (MIT Technology Review)

Volkswagen is investing $1 billion in the EV startup Rivian. The deal has the two companies creating a joint venture, and it could provide a path forward for Rivian, which has faced some struggles getting its vehicles to market. (TechCrunch)

The cost of building the perfect wave

For nearly as long as surfing has existed, surfers have been obsessed with the search for the perfect wave. It’s not just a question of size, but also of shape, surface conditions, and duration—ideally in a beautiful natural environment. 

While this hunt has taken surfers from tropical coastlines reachable only by boat to swells breaking off icebergs, these days—as the sport goes mainstream—that search may take place closer to home. That is, at least, the vision presented by developers and boosters in the growing industry of surf pools, spurred by advances in wave-­generating technology that have finally created artificial waves surfers actually want to ride. 

Some surf evangelists think these pools will democratize the sport, making it accessible to more communities far from the coasts—while others are simply interested in cashing in. But a years-long fight over a planned surf pool in Thermal, California, shows that for many people who live in the places where they’re being built, the calculus isn’t about surf at all. 


Just some 30 miles from Palm Springs, on the southeastern edge of the Coachella Valley desert, Thermal is the future home of the 118-acre private, members-only Thermal Beach Club (TBC). The developers promise over 300 luxury homes with a dazzling array of amenities; the planned centerpiece is a 20-plus-acre artificial lagoon with a 3.8-acre surf pool offering waves up to seven feet high. According to an early version of the website, club memberships will start at $175,000 a year. (TBC’s developers did not respond to multiple emails asking for comment.)

That price tag makes it clear that the club is not meant for locals. Thermal, an unincorporated desert community, currently has a median family income of $32,340. Most of its residents are Latino; many are farmworkers. The community lacks much of the basic infrastructure that serves the western Coachella Valley, including public water service—leaving residents dependent on aging private wells for drinking water. 

Just a few blocks away from the TBC site is the 60-acre Oasis Mobile Home Park. A dilapidated development designed for some 1,500 people in about 300 mobile homes, Oasis has been plagued for decades by a lack of clean drinking water. The park owners have been cited numerous times by the Environmental Protection Agency for providing tap water contaminated with high levels of arsenic, and last year, the US Department of Justice filed a lawsuit against them for violating the Safe Drinking Water Act. Some residents have received assistance to relocate, but many of those who remain rely on weekly state-funded deliveries of bottled water and on the local high school for showers. 

Stephanie Ambriz, a 28-year-old special-needs teacher who grew up near Thermal, recalls feeling “a lot of rage” back in early 2020 when she first heard about plans for the TBC development. Ambriz and other locals organized a campaign against the proposed club, which she says the community doesn’t want and won’t be able to access. What residents do want, she tells me, is drinkable water, affordable housing, and clean air—and to have their concerns heard and taken seriously by local officials. 

Despite the grassroots pushback, which twice led to delays to allow more time for community feedback, the Riverside County Board of Supervisors unanimously approved the plans for the club in October 2020. It was, Ambriz says, “a shock to see that the county is willing to approve these luxurious developments when they’ve ignored community members” for decades. (A Riverside County representative did not respond to specific questions about TBC.) 

The desert may seem like a counterintuitive place to build a water-intensive surf pool, but the Coachella Valley is actually “the very best place to possibly put one of these things,” argues Doug Sheres, the developer behind DSRT Surf, another private pool planned for the area. It is “close to the largest [and] wealthiest surf population in the world,” he says, featuring “360 days a year of surfable weather” and mountain and lake views in “a beautiful resort setting” served by “a very robust aquifer.” 

In addition to the two planned projects, the Palm Springs Surf Club (PSSC) has already opened locally. The trifecta is turning the Coachella Valley into “the North Shore of wave pools,” as one aficionado described it to Surfer magazine. 

The effect is an acute cognitive dissonance—one that I experienced after spending a few recent days crisscrossing the valley and trying out the waves at PSSC. But as odd as this setting may seem, an analysis by MIT Technology Review reveals that the Coachella Valley is not the exception. Of an estimated 162 surf pools that have been built or announced around the world, as tracked by the industry publication Wave Pool Magazine, 54 are in areas considered by the nonprofit World Resources Institute (WRI) to face high or extremely high water stress, meaning that they regularly use a large portion of their available surface water supply annually. Regions in the “extremely high” category consume 80% or more of their water, while those in the “high” category use 40% to 80% of their supply. (Not all of Wave Pool Magazine’s listed pools will be built, but the publication tracks all projects that have been announced. Some have closed and over 60 are currently operational.)

Zoom in on the US and nearly half are in places with high or extremely high water stress, roughly 16 in areas served by the severely drought-stricken Colorado River. The greater Palm Springs area falls under the highest category of water stress, according to Samantha Kuzma, a WRI researcher (though she notes that WRI’s data on surface water does not reflect all water sources, including an area’s access to aquifers, or its water management plan).

Now, as TBC’s surf pool and other planned facilities move forward and contribute to what’s becoming a multibillion-dollar industry with proposed sites on every continent except Antarctica, inland waves are increasingly becoming a flash point for surfers, developers, and local communities. There are at least 29 organized movements in opposition to surf clubs around the world, according to an ongoing survey from a coalition called No to the Surf Park in Canéjan, which includes 35 organizations opposing a park in Bordeaux, France.  

While the specifics vary widely, at the core of all these fights is a question that’s also at the heart of the sport: What is the cost of finding, or now creating, the perfect wave—and who will have to bear it? 


Though wave pools have been around since the late 1800s, the first artificial surfing wave was built in 1969, and also in the desert—at Big Surf in Tempe, Arizona. But at that pool and its early successors, surfing was secondary; people who went to those parks were more interested in splashing around, and surfers themselves weren’t too excited by what they had to offer. The manufactured waves were too small and too soft, without the power, shape, or feel of the real thing. 

The tide really turned in 2015, when Kelly Slater, widely considered to be the greatest professional surfer of all time, was filmed riding a six-foot-tall, 50-second barreling wave. As the viral video showed, he was not in the wild but atop a wave generated in a pool in California’s Central Valley, some 100 miles from the coast.

Waves of that height, shape, and duration are a rarity even in the ocean, but “Kelly’s wave,” as it became known, showed that “you can make waves in the pool that are as good as or better than what you get in the ocean,” recalls Sheres, the developer whose company, Beach Street Development, is building mul­tiple surf pools around the country, including DSRT Surf. “That got a lot of folks excited—myself included.” 

In the ocean, a complex combination of factors—including wind direction, tide, and the shape and features of the seafloor—is required to generate a surfable wave. Re-creating them in an artificial environment required years of modeling, precise calculations, and simulations. 

Surf Ranch, Slater’s project in the Central Valley, built a mechanical system in which a 300-ton hydrofoil—which resembles a gigantic metal fin—is pulled along the length of a pool 700 yards long and 70 yards wide by a mechanical device the size of several train cars running on a track. The bottom of the pool is precisely contoured to mimic reefs and other features of the ocean floor; as the water hits those features, its movement creates the 50-second-long barreling wave. Once the foil reaches one end of the pool, it runs backwards, creating another wave that breaks in the opposite direction. 

While the result is impressive, the system is slow, producing just one wave every three to four minutes. 

Around the same time Slater’s team was tinkering with his wave, other companies were developing their own technologies to produce multiple waves, and to do so more rapidly and efficiently—key factors in commercial viability. 

Fundamentally, all the systems create waves by displacing water, but depending on the technology deployed, there are differences in the necessary pool size, the project’s water and energy requirements, the level of customization that’s possible, and the feel of the wave. 

Thomas Lochtefeld is a pioneer in the field and the CEO of Surf Loch, which powers PSSC’s waves. Surf Loch uses pneumatic technology, in which compressed air cycles water through chambers the size of bathroom stalls and lets operators create countless wave patterns.

One demo pool in Australia uses what looks like a giant mechanical doughnut that sends out waves the way a pebble dropped in water sends out ripples. Another proposed plan uses a design that spins out waves from a circular fan—a system that is mobile and can be placed in existing bodies of water. 

Of the two most popular techniques in commercial use, one relies on modular paddles attached to a pier that runs across a pool, which move in precise ways to generate waves. The other is pneumatic technology, which uses compressed air to push water through chambers the size of bathroom stalls, called caissons; the caissons pull in water and then push it back out into the pool. By choosing which modular paddles or caissons move first against the different pool bottoms, and with how much force at a time, operators can create a range of wave patterns. 

Regardless of the technique used, the design and engineering of most modern wave pools are first planned out on a computer. Waves are precisely calculated, designed, simulated, and finally tested in the pool with real surfers before they are set as options on a “wave menu” in proprietary software that surf-pool technologists say offers a theoretically endless number and variety of waves. 

On a Tuesday afternoon in early April, I am the lucky tester at the Palm Springs Surf Club, which uses pneumatic technology, as the team tries out a shoulder-high right-breaking wave. 

I have the pool to myself as the club prepares to reopen; it had closed to rebuild its concrete “beach” just 10 days after its initial launch because the original beach had not been designed to withstand the force of the larger waves that Surf Loch, the club’s wave technology provider, had added to the menu at the last minute. (Weeks after reopening in April, the surf pool closed again as the result of “a third-party equipment supplier’s failure,” according to Thomas Lochtefeld, Surf Loch’s CEO.)

I paddle out and, at staffers’ instructions, take my position a few feet away from the third caisson from the right, which they say is the ideal spot to catch the wave on the shoulder—meaning the unbroken part of the swell closest to its peak. 

The entire experience is surreal: waves that feel like the ocean in an environment that is anything but. 

Palm Springs Surf Club wide angle vie wof the wave pool
An employee test rides a wave, which was first calculated, designed, and simulated on a computer.
SPENCER LOWELL

In some ways, these pneumatic waves are better than what I typically ride around Los Angeles—more powerful, more consistent, and (on this day, at least) uncrowded. But the edge of the pool and the control tower behind it are almost always in my line of sight. And behind me are the PSSC employees (young men, incredible surfers, who keep an eye on my safety and provide much-needed tips) and then, behind them, the snow-capped San Jacinto Mountains. At the far end of the pool, behind the recently rebuilt concrete beach, is a restaurant patio full of diners who I can’t help but imagine are judging my every move. Still, for the few glorious seconds that I ride each wave, I am in the same flow state I experience in the ocean itself.  

Then I fall and sheepishly paddle back to PSSC’s encouraging surfer-employees to restart the whole process. I would be having a lot of fun—if I could just forget my self-consciousness, and the jarring feeling that I shouldn’t be riding waves in the middle of the desert at all.  


Though long inhabited by Cahuilla Indians, the Coachella Valley was sparsely populated until 1876, when the Southern Pacific Railroad added a new line out to the middle of the arid expanse. Shortly after, the first non-native settlers came to the valley and realized that its artesian wells, which flow naturally without the need to be pumped, provided ideal conditions for farming.  

Agricultural production exploded, and by the early 1900s, these once freely producing wells were putting out significantly less, leading residents to look for alternative water sources. In 1918, they created the Coachella Valley Water District (CVWD) to import water from the Colorado River via a series of canals. This water was used to supply the region’s farms and recharge the Coachella Aquifer, the region’s main source of drinking water. 

The author tests a shoulder-high wave at PSSC, where she says the waves were in some ways better than what she rides around Los Angeles.
SPENCER LOWELL

The water imports continue to this day—though the seven states that draw on the river are currently renegotiating their water rights amid a decades-long megadrought in the region. 

The imported water, along with CVWD’s water management plan, has allowed Coachella’s aquifer to maintain relatively steady levels “going back to 1970, even though most development and population has occurred since,” Scott Burritt, a CVWD spokesperson, told MIT Technology Review in an email. 

This has sustained not only agriculture but also tourism in the valley, most notably its world-class—and water-intensive—golf courses. In 2020, the 120 golf courses under the jurisdiction of the CVWD consumed 105,000 acre-feet of water per year (AFY); that’s an average of 875 AFY, or 285 million gallons per year per course. 

Surf pools’ proponents frequently point to the far larger amount of water golf courses consume to argue that opposing the pools on grounds of their water use is misguided. 

PSSC, the first of the area’s three planned surf clubs to open, requires an estimated 3 million gallons per year to fill its pool; the proposed DSRT Surf holds 7 million gallons and estimates that it will use 24 million gallons per year, which includes maintenance and filtration, and accounts for evaporation. TBC’s planned 20-acre recreational lake, 3.8 acres of which will contain the surf pool, will use 51 million gallons per year, according to Riverside County documents. Unlike standard swimming pools, none of these pools need to be drained and refilled annually for maintenance, saving on potential water use. DSRT Surf also boasts about plans to offset its water use by replacing 1 million square feet of grass from an adjacent golf course with drought-tolerant plants. 

a PSSC employee at a control panel overlooking the pool
Pro surfer and PSSC’s full-time “wave curator” Cheyne Magnusson watches test waves from the club’s control tower.
SPENCER LOWELL

With surf parks, “you can see the water,” says Jess Ponting, a cofounder of Surf Park Central, the main industry association, and Stoke, a nonprofit that aims to certify surf and ski resorts—and, now, surf pools—for sustainability. “Even though it’s a fraction of what a golf course is using, it’s right there in your face, so it looks bad.”

But even if it were just an issue of appearance, public perception is important when residents are being urged to reduce their water use, says Mehdi Nemati, an associate professor of environmental economics and policy at the University of California, Riverside. It’s hard to demand such efforts from people who see these pools and luxury developments being built around them, he says. “The questions come: Why do we conserve when there are golf courses or surfing … in the desert?” 

(Burritt, the CVWD representative, notes that the water district “encourages all customers, not just residents, to use water responsibly” and adds that CVWD’s strategic plans project that there should be enough water to serve both the district’s golf courses and its surf pools.)  

Locals opposing these projects, meanwhile, argue that developers are grossly underestimating their water use, and various engineering firms and some county officials have in fact offered projections that differ from the developers’ estimates. Opponents are specifically concerned about the effects of spray, evaporation, and other factors, which increase with higher temperatures, bigger waves, and larger pool sizes. 

As a rough point of reference, Slater’s 14-acre wave pool in Lemoore, California, can lose up to 250,000 gallons of water per day to evaporation, according to Adam Fincham, the engineer who designed the technology. That’s roughly half an Olympic swimming pool.

More fundamentally, critics take issue with even debating whether surf clubs or golf courses are worse. “We push back against all of it,” says Ambriz, who organized opposition to TBC and argues that neither the pool nor an exclusive new golf course in Thermal benefits the local community. Comparing them, she says, obscures greater priorities, like the water needs of households. 

Five surfers sit on their boards in a calm PSSC pool
The PSSC pool requires an estimated 3 million gallons of water per year. On top of a $40 admission fee, a private session there would cost between $3,500 and $5,000 per hour.
SPENCER LOWELL

The “primary beneficiary” of the area’s water, says Mark Johnson, who served as CVWD’s director of engineering from 2004 to 2016, “should be human consumption.”

Studies have shown that just one AFY, or nearly 326,000 gallons, is generally enough to support all household water needs of three California families every year. In Thermal, the gap between the demands of the surf pool and the needs of the community is even more stark: each year for the past three years, nearly 36,000 gallons of water have been delivered, in packages of 16-ounce plastic water bottles, to residents of the Oasis Mobile Home Park—some 108,000 gallons in all. Compare that with the 51 million gallons that will be used annually by TBC’s lake: it would be enough to provide drinking water to its neighbors at Oasis for the next 472 years.

Furthermore, as Nemati notes, “not all water is the same.” CVWD has provided incentives for golf courses to move toward recycled water and replace grass with less water-­intensive landscaping. But while recycled water and even rainwater have been proposed as options for some surf pools elsewhere in the world, including France and Australia, this is unrealistic in Coachella, which receives just three to four inches of rain per year. 

Instead, the Coachella Valley surf pools will depend on a mix of imported water and nonpotable well water from Coachella’s aquifer. 

But any use of the aquifer worries Johnson. Further drawing down the water, especially in an underground aquifer, “can actually create water quality problems,” he says, by concentrating “naturally occurring minerals … like chromium and arsenic.” In other words, TBC could worsen the existing problem of arsenic contamination in local well water. 

When I describe to Ponting MIT Technology Review’s analysis showing how many surf pools are being built in desert regions, he seems to concede it’s an issue. “If 50% of the surf parks in development are in water-stressed areas,” he says, “then the developers are not thinking about the right things.” 


Before visiting the future site of Thermal Beach Club, I stopped in La Quinta, a wealthy town where, back in 2022, community opposition successfully stopped plans for a fourth pool planned for the Coachella Valley. This one was developed by the Kelly Slater Wave Company, which was acquired by the World Surf League in 2016. 

Alena Callimanis, a longtime resident who was a member of the community group that helped defeat the project, says that for a year and a half, she and other volunteers often spent close to eight hours a day researching everything they could about surf pools—and how to fight them. “We knew nothing when we started,” she recalls. But the group learned quickly, poring over planning documents, consulting hydrologists, putting together presentations, providing comments at city council hearings, and even conducting their own citizen science experiments to test the developers’ assertions about the light and noise pollution the project could create. (After the council rejected the proposal for the surf club, the developers pivoted to previously approved plans for a golf course. Callimanis’s group also opposes the golf course, raising similar concerns about water use, but since plans have already been approved, she says, there is little they can do to fight back.) 

view across an intersection of a mobile home framed by palm trees
Just a few blocks from the site of the planned Thermal Beach Club is the Oasis Mobile Home Park, which has been plagued for decades by a lack of clean drinking water.
A water pump sits at the
corner of farm fields in Thermal, California,
where irrigation water is imported from the
Colorado River.

It was a different story in Thermal, where three young activists juggled jobs and graduate programs as they tried to mobilize an under-resourced community. “Folks in Thermal lack housing, lack transportation, and they don’t have the ability to take a day off from work to drive up and provide public comment,” says Ambriz. 

But the local pushback did lead to certain promises, including a community benefit payment of $2,300 per luxury housing unit, totaling $749,800. In the meeting approving the project, Riverside County supervisor Manuel Perez called this “unprecedented” and credited the efforts of Ambriz and her peers. (Ambriz remains unconvinced. “None of that has happened,” she says, and payments to the community don’t solve the underlying water issues that the project could exacerbate.) 

That affluent La Quinta managed to keep a surf pool out of its community where working-class Thermal failed is even more jarring in light of industry rhetoric about how surf pools could democratize the sport. For Bryan Dickerson, the editor in chief of Wave Pool Magazine, the collective vision for the future is that instead of “the local YMCA … putting in a skate park, they put in a wave pool.” Other proponents, like Ponting, describe how wave pools can provide surf therapy or opportunities for underrepresented groups. A design firm in New York City, for example, has proposed to the city a plan for an indoor wave pool in a low-income, primarily black and Latino neighborhood in Queens—for $30 million. 

For its part, PSSC cost an estimated $80 million to build. On top of a $40 general admission fee, a private session like the one I had would cost $3,500 to $5,000 per hour, while a public session would be at least $100 to $200, depending on the surfer’s skill level and the types of waves requested. 

In my two days traversing the 45-mile Coachella Valley, I kept thinking about how this whole area was an artificial oasis made possible only by innovations that changed the very nature of the desert, from the railroad stop that spurred development to the irrigation canals and, later, the recharge basins that stopped the wells from running out. 

In this transformed environment, I can see how the cognitive dissonance of surfing a desert wave begins to shrink, tempting us to believe that technology can once again override the reality of living (or simply playing) in the desert in a warming and drying world. 

But the tension over surf pools shows that when it comes to how we use water, maybe there’s no collective “us” here at all. 

Last summer was the hottest in 2,000 years. Here’s how we know.

This article is from The Spark, MIT Technology Review’s weekly climate newsletter. To receive it in your inbox every Wednesday, sign up here.

I’m ready for summer, but if this year is anything like last year, it’s going to be a doozy. In fact, the summer of 2023 in the Northern Hemisphere was the hottest in over 2,000 years, according to a new study released this week. 

If you’ve been following the headlines, you probably already know that last year was a hot one. But I was gobsmacked by this paper’s title when it came across my desk. The warmest in 2,000 years—how do we even know that?

There weren’t exactly thermometers around in the year 1, so scientists have to get creative when it comes to comparing our climate today with that of centuries, or even millennia, ago. Here’s how our world stacks up against the climate of the past, how we know, and why it matters for our future. 

Today, there are thousands and thousands of weather stations around the globe, tracking the temperature from Death Valley to Mount Everest. So there’s plenty of data to show that 2023 was, in a word, a scorcher. 

Daily global ocean temperatures were the warmest ever recorded for over a year straight. Levels of sea ice hit new lows. And of course, the year saw the highest global average temperatures since record-keeping began in 1850.  

But scientists decided to look even further back into the past for a year that could compare to our current temperatures. To do so, they turned to trees, which can act as low-tech weather stations.

The concentric rings inside a tree are evidence of the plant’s yearly growth cycles. Lighter colors correspond to quick growth over the spring and summer, while the darker rings correspond to the fall and winter. Count the pairs of light and dark rings, and you can tell how many years a tree has lived. 

Trees tend to grow faster during warm, wet years and slower during colder ones. So scientists can not only count the rings but measure their thickness, and use that as a gauge for how warm any particular year was. They also look at factors like density and track different chemical signatures found inside the wood. You don’t even need to cut down a tree to get its help with climatic studies—you can just drill out a small cylinder from the tree’s center, called a core, and study the patterns.

The oldest living trees allow us to peek a few centuries into the past. Beyond that, it’s a matter of cross-referencing the patterns on dead trees with living ones, extending the record back in time like putting a puzzle together. 

It’s taken several decades of work and hundreds of scientists to develop the records that researchers used for this new paper, said Max Torbenson, one of the authors of the study, on a press call. There are over 10,000 trees from nine regions across the Northern Hemisphere represented, allowing the researchers to draw conclusions about individual years over the past two millennia. The year 246 CE once held the crown for the warmest summer in the Northern Hemisphere in the last 2,000 years. But 25 of the last 28 years have beat that record, Torbenson says, and 2023’s summer tops them all. 

These conclusions are limited to the Northern Hemisphere, since there are only a few tree ring records from the Southern Hemisphere, says Jan Esper, lead author of the new study. And using tree rings doesn’t work very well for the tropics because seasons look different there, he adds. Since there’s no winter, there’s usually not as reliable an alternating pattern in tropical tree rings, though some trees do have annual rings that track the wet and dry periods of the year. 

Paleoclimatologists, who study ancient climates, can use other methods to get a general idea of what the climate looked like even earlier—tens of thousands to millions of years ago. 

The biggest difference between the new study using tree rings and methods of looking back further into the past is the precision. Scientists can, with reasonable certainty, use tree rings to draw conclusions about individual years in the Northern Hemisphere (536 CE was the coldest, for instance, likely because of volcanic activity). Any information from further back than the past couple of thousand years will be more of a general trend than a specific data point representing a single year. But those records can still be very useful. 

The oldest glaciers on the planet are at least a million years old, and scientists can drill down into the ice for samples. By examining the ratio of gases like oxygen, carbon dioxide, and nitrogen inside these ice cores, researchers can figure out the temperature of the time corresponding to the layers in the glacier. The oldest continuous ice-core record, which was collected in Antarctica, goes back about 800,000 years. 

Researchers can use fossils to look even further back into Earth’s temperature record. For one 2020 study, researchers drilled into the seabed and looked at the sediment and tiny preserved shells of ancient organisms. From the chemical signatures in those samples, they found that the temperatures we might be on track to record may be hotter than anything the planet has experienced on a global scale in tens of millions of years. 

It’s a bit sobering to know that we’re changing the planet in such a dramatic way. 

The good news is, we know what we need to do to turn things around: cut emissions of planet-warming gases like carbon dioxide and methane. The longer we wait, the more expensive and difficult it will be to stop warming and reverse it, as Esper said on the press call: “We should do as much as possible, as soon as possible.” 


Now read the rest of The Spark

Related reading

Last year broke all sorts of climate records, from emissions to ocean temperatures. For more on the data, check out this story from December.

How hot is too hot for the human body? I tackled that very question in a 2021 story.  

Two engineers in lab coats monitor the thermal battery powering a conveyor belt of bottles

SIMON LANDREIN

Another thing

Readers chose thermal batteries as the 11th Breakthrough Technology of 2024. If you want to hear more about what thermal batteries are, how they work, and why this all matters, join us for the latest in our Roundtables series of online events, where I’ll be getting into the nitty-gritty details and answering some audience questions.

This event is exclusively for subscribers, so subscribe if you haven’t already, and then register here to join us tomorrow, May 16, at noon Eastern time. Hope to see you there! 

Keeping up with climate  

Scientists just recorded the largest ever annual leap in the amount of carbon dioxide in the atmosphere. The concentration of the planet-warming gas in March 2024 was 4.7 parts per million higher than it was a year before. (The Guardian)

Tesla has reportedly begun rehiring some of the workers who were laid off from its charging team in recent weeks. (Bloomberg)

→ To catch up on what’s going on at Tesla, and what it means for the future of EV charging and climate tech more broadly, check out the newsletter from last week if you missed it. (MIT Technology Review)

A new rule could spur thousands of miles of new power lines, making it easier to add renewables to the grid in the US. The Federal Energy Regulatory Commission will require grid operators to plan 20 years ahead, considering things like the speed of wind and solar installations. (New York Times)

Where does carbon dioxide go after it’s been vacuumed out of the atmosphere? Here are 10 options. (Latitude Media)

Ocean temperatures have been extremely high, shattering records over the past year. All that heat could help fuel a particularly busy upcoming hurricane season. (E&E News)

New tariffs in the US will tack on additional costs to a wide range of Chinese imports, including batteries and solar cells. The tariff on EVs will take a particularly drastic jump, going from 27.5% to 102.5%. (Associated Press)

A reporter took a trip to the Beijing Auto Show and drove dozens of EVs. His conclusion? Chinese EVs are advancing much faster than Western automakers can keep up with. (InsideEVs)

Harnessing solar power via satellites in space and beaming it down to Earth is a tempting dream. But the reality, as you might expect, is probably not so rosy. (IEEE Spectrum)

This grim but revolutionary DNA technology is changing how we respond to mass disasters

Seven days

No matter who he called—his mother, his father, his brother, his cousins—the phone would just go to voicemail. Cell service was out around Maui as devastating wildfires swept through the Hawaiian island. But while Raven Imperial kept hoping for someone to answer, he couldn’t keep a terrifying thought from sneaking into his mind: What if his family members had perished in the blaze? What if all of them were gone?

Hours passed; then days. All Raven knew at that point was this: there had been a wildfire on August 8, 2023, in Lahaina, where his multigenerational, tight-knit family lived. But from where he was currently based in Northern California, Raven was in the dark. Had his family evacuated? Were they hurt? He watched from afar as horrifying video clips of Front Street burning circulated online.

Much of the area around Lahaina’s Pioneer Mill Smokestack was totally destroyed by wildfire.
ALAMY

The list of missing residents meanwhile climbed into the hundreds.

Raven remembers how frightened he felt: “I thought I had lost them.”

Raven had spent his youth in a four-bedroom, two-bathroom, cream-colored home on Kopili Street that had long housed not just his immediate family but also around 10 to 12 renters, since home prices were so high on Maui. When he and his brother, Raphael Jr., were kids, their dad put up a basketball hoop outside where they’d shoot hoops with neighbors. Raphael Jr.’s high school sweetheart, Christine Mariano, later moved in, and when the couple had a son in 2021, they raised him there too.

From the initial news reports and posts, it seemed as if the fire had destroyed the Imperials’ entire neighborhood near the Pioneer Mill Smokestack—a 225-foot-high structure left over from the days of Maui’s sugar plantations, which Raven’s grandfather had worked on as an immigrant from the Philippines in the mid-1900s.

Then, finally, on August 11, a call to Raven’s brother went through. He’d managed to get a cell signal while standing on the beach.

“Is everyone okay?” Raven asked.

“We’re just trying to find Dad,” Raphael Jr. told his brother.

Raven Imperial sitting in the grass
From his current home in Northern California, Raven Imperial spent days not knowing what had happened to his family in Maui.
WINNI WINTERMEYER

In the three days following the fire, the rest of the family members had slowly found their way back to each other. Raven would learn that most of his immediate family had been separated for 72 hours: Raphael Jr. had been marooned in Kaanapali, four miles north of Lahaina; Christine had been stuck in Wailuku, more than 20 miles away; both young parents had been separated from their son, who escaped with Christine’s parents. Raven’s mother, Evelyn, had also been in Kaanapali, though not where Raphael Jr. had been.

But no one was in contact with Rafael Sr. Evelyn had left their home around noon on the day of the fire and headed to work. That was the last time she had seen him. The last time they had spoken was when she called him just after 3 p.m. and asked: “Are you working?” He replied “No,” before the phone abruptly cut off.

“Everybody was found,” Raven says. “Except for my father.”

Within the week, Raven boarded a plane and flew back to Maui. He would keep looking for him, he told himself, for as long as it took.


That same week, Kim Gin was also on a plane to Maui. It would take half a day to get there from Alabama, where she had moved after retiring from the Sacramento County Coroner’s Office in California a year earlier. But Gin, now an independent consultant on death investigations, knew she had something to offer the response teams in Lahaina. Of all the forensic investigators in the country, she was one of the few who had experience in the immediate aftermath of a wildfire on the vast scale of Maui’s. She was also one of the rare investigators well versed in employing rapid DNA analysis—an emerging but increasingly vital scientific tool used to identify victims in unfolding mass-casualty events.

Gin started her career in Sacramento in 2001 and was working as the coroner 17 years later when Butte County, California, close to 90 miles north, erupted in flames. She had worked fire investigations before, but nothing like the Camp Fire, which burned more than 150,000 acres—an area larger than the city of Chicago. The tiny town of Paradise, the epicenter of the blaze, didn’t have the capacity to handle the rising death toll. Gin’s office had a refrigerated box truck and a 52-foot semitrailer, as well as a morgue that could handle a couple of hundred bodies.

Kim Gin
Kim Gin, the former Sacramento County coroner, had worked fire investigations in her career, but nothing prepared her for the 2018 Camp Fire.
BRYAN TARNOWSKI

“Even though I knew it was a fire, I expected more identifications by fingerprints or dental [records]. But that was just me being naïve,” she says. She quickly realized that putting names to the dead, many burned beyond recognition, would rely heavily on DNA.

“The problem then became how long it takes to do the traditional DNA [analysis],” Gin explains, speaking to a significant and long-standing challenge in the field—and the reason DNA identification has long been something of a last resort following large-scale disasters.

While more conventional identification methods—think fingerprints, dental information, or matching something like a knee replacement to medical records—can be a long, tedious process, they don’t take nearly as long as traditional DNA testing.

Historically, the process of making genetic identifications would often stretch on for months, even years. In fires and other situations that result in badly degraded bone or tissue, it can become even more challenging and time consuming to process DNA, which traditionally involves reading the 3 billion base pairs of the human genome and comparing samples found in the field against samples from a family member. Meanwhile, investigators frequently need equipment from the US Department of Justice or the county crime lab to test the samples, so backlogs often pile up.

A supply kit with swabs, gloves, and other items needed to take a DNA sample in the field.
A demo chip for ANDE’s rapid DNA box.

This creates a wait that can be horrendous for family members. Death certificates, federal assistance, insurance money—“all that hinges on that ID,” Gin says. Not to mention the emotional toll of not knowing if their loved ones are alive or dead.

But over the past several years, as fires and other climate-change-fueled disasters have become more common and more cataclysmic, the way their aftermath is processed and their victims identified has been transformed. The grim work following a disaster remains—surveying rubble and ash, distinguishing a piece of plastic from a tiny fragment of bone—but landing a positive identification can now take just a fraction of the time it once did, which may in turn bring families some semblance of peace more swiftly than ever before.

The key innovation driving this progress has been rapid DNA analysis, a methodology that focuses on just over two dozen regions of the genome. The 2018 Camp Fire was the first time the technology was used in a large, live disaster setting, and the first time it was used as the primary way to identify victims. The technology—deployed in small high-tech field devices developed by companies like industry leader ANDE, or in a lab with other rapid DNA techniques developed by Thermo Fisher—is increasingly being used by the US military on the battlefield, and by the FBI and local police departments after sexual assaults and in instances where confirming an ID is challenging, like cases of missing or murdered Indigenous people or migrants. Yet arguably the most effective way to use rapid DNA is in incidents of mass death. In the Camp Fire, 22 victims were identified using traditional methods, while rapid DNA analysis helped with 62 of the remaining 63 victims; it has also been used in recent years following hurricanes and floods, and in the war in Ukraine.

“These families are going to have to wait a long period of time to get identification. How do we make this go faster?”

Tiffany Roy, a forensic DNA expert with consulting company ForensicAid, says she’d be concerned about deploying the technology in a crime scene, where quality evidence is limited and can be quickly “exhausted” by well-meaning investigators who are “not trained DNA analysts.” But, on the whole, Roy and other experts see rapid DNA as a major net positive for the field. “It is definitely a game-changer,” adds Sarah Kerrigan, a professor of forensic science at Sam Houston State University and the director of its Institute for Forensic Research, Training, and Innovation.

But back in those early days after the Camp Fire, all Gin knew was that nearly 1,000 people had been listed as missing, and she was tasked with helping to identify the dead. “Oh my goodness,” she remembers thinking. “These families are going to have to wait a long period of time to get identification. How do we make this go faster?”


Ten days

One flier pleading for information about “Uncle Raffy,” as people in the community knew Rafael Sr., was posted on a brick-red stairwell outside Paradise Supermart, a Filipino store and restaurant in Kahului, 25 miles away from the destruction. In it, just below the words “MISSING Lahaina Victim,” the 63-year-old grandfather smiled with closed lips, wearing a blue Hawaiian shirt, his right hand curled in the shaka sign, thumb and pinky pointing out.

Raphael Imperial Sr
Raven remembers how hard his dad, Rafael, worked. His three jobs took him all over town and earned him the nickname “Mr. Aloha.”
COURTESY OF RAVEN IMPERIAL

“Everybody knew him from restaurant businesses,” Raven says. “He was all over Lahaina, very friendly to everybody.” Raven remembers how hard his dad worked, juggling three jobs: as a draft tech for Anheuser-Busch, setting up services and delivering beer all across town; as a security officer at Allied Universal security services; and as a parking booth attendant at the Sheraton Maui. He connected with so many people that coworkers, friends, and other locals gave him another nickname: “Mr. Aloha.”

Raven also remembers how his dad had always loved karaoke, where he would sing “My Way,” by Frank Sinatra. “That’s the only song that he would sing,” Raven says. “Like, on repeat.” 

Since their home had burned down, the Imperials ran their search out of a rental unit in Kihei, which was owned by a local woman one of them knew through her job. The woman had opened her rental to three families in all. It quickly grew crowded with side-by-side beds and piles of donations.

Each day, Evelyn waited for her husband to call.

She managed to catch up with one of their former tenants, who recalled asking Rafael Sr. to leave the house on the day of the fires. But she did not know if he actually did. Evelyn spoke to other neighbors who also remembered seeing Rafael Sr. that day; they told her that they had seen him go back into the house. But they too did not know what happened to him after.

A friend of Raven’s who got into the largely restricted burn zone told him he’d spotted Rafael Sr.’s Toyota Tacoma on the street, not far from their house. He sent a photo. The pickup was burned out, but a passenger-side door was open. The family wondered: Could he have escaped?

Evelyn called the Red Cross. She called the police. Nothing. They waited and hoped.


Back in Paradise in 2018, as Gin worried about the scores of waiting families, she learned there might in fact be a better way to get a positive ID—and a much quicker one. A company called ANDE Rapid DNA had already volunteered its services to the Butte County sheriff and promised that its technology could process DNA and get a match in less than two hours.

“I’ll try anything at this point,” Gin remembers telling the sheriff. “Let’s see this magic box and what it’s going to do.”

In truth, Gin did not think it would work, and certainly not in two hours. When the device arrived, it was “not something huge and fantastical,” she recalls thinking. A little bigger than a microwave, it looked “like an ordinary box that beeps, and you put stuff in, and out comes a result.”

The “stuff,” more specifically, was a cheek or bloodstain swab, or a piece of muscle, or a fragment of bone that had been crushed and demineralized. Instead of reading 3 billion base pairs in this sample, Selden’s machine examined just 27 genome regions characterized by particular repeating sequences. It would be nearly impossible for two unrelated people to have the same repeating sequence in those regions. But a parent and child, or siblings, would match, meaning you could compare DNA found in human remains with DNA samples taken from potential victims’ family members. Making it even more efficient for a coroner like Gin, the machine could run up to five tests at a time and could be operated by anyone with just a little basic training.

ANDE’s chief scientific officer, Richard Selden, a pediatrician who has a PhD in genetics from Harvard, didn’t come up with the idea to focus on a smaller, more manageable number of base pairs to speed up DNA analysis. But it did become something of an obsession for him after he watched the O.J. Simpson trial in the mid-1990s and began to grasp just how long it took for DNA samples to get processed in crime cases. By this point, the FBI had already set up a system for identifying DNA by looking at just 13 regions of the genome; it would later add seven more. Researchers in other countries had also identified other sets of regions to analyze. Drawing on these various methodologies, Selden homed in on the 27 specific areas of DNA he thought would be most effective to examine, and he launched ANDE in 2004.

But he had to build a device to do the analysis. Selden wanted it to be small, portable, and easily used by anyone in the field. In a conventional lab, he says, “from the moment you take that cheek swab to the moment that you have the answer, there are hundreds of laboratory steps.” Traditionally, a human is holding test tubes and iPads and sorting through or processing paperwork. Selden compares it all to using a “conventional typewriter.” He effectively created the more efficient laptop version of DNA analysis by figuring out how to speed up that same process.

No longer would a human have to “open up this bottle and put [the sample] in a pipette and figure out how much, then move it into a tube here.” It is all automated, and the process is confined to a single device.

gloved hands load a chip cartridge into the ANDE machine
The rapid DNA analysis boxes from ANDE can be used in the field by anyone with just a bit of training.
ANDE

Once a sample is placed in the box, the DNA binds to a filter in water and the rest of the sample is washed away. Air pressure propels the purified DNA to a reconstitution chamber and then flattens it into a sheet less than a millimeter thick, which is subjected to about 6,000 volts of electricity. It’s “kind of an obstacle course for the DNA,” he explains.

The machine then interprets the donor’s genome and and provides an allele table with a graph showing the peaks for each region and its size. This data is then compared with samples from potential relatives, and the machine reports when it has a match.

Rapid DNA analysis as a technology first received approval for use by the US military in 2014, and in the FBI two years later. Then the Rapid DNA Act of 2017 enabled all US law enforcement agencies to use the technology on site and in real time as an alternative to sending samples off to labs and waiting for results.

But by the time of the Camp Fire the following year, most coroners and local police officers still had no familiarity or experience with it. Neither did Gin. So she decided to put the “magic box” through a test: she gave Selden, who had arrived at the scene to help with the technology, a DNA sample from a victim whose identity she’d already confirmed via fingerprint. The box took about 90 minutes to come back with a result. And to Gin’s surprise, it was the same identification she had already made. Just to make sure, she ran several more samples through the box, also from victims she had already identified. Again, results were returned swiftly, and they confirmed hers.

“I was a believer,” she says.

The next year, Gin helped investigators use rapid DNA technology in the 2019 Conception disaster, when a dive boat caught fire off the Channel Islands in Santa Barbara. “We ID’d 34 victims in 10 days,” Gin says. “Completely done.” Gin now works independently to assist other investigators in mass-fatality events and helps them learn to use the ANDE system.

Its speed made the box a groundbreaking innovation. Death investigations, Gin learned long ago, are not as much about the dead as about giving peace of mind, justice, and closure to the living.


Fourteen days

Many of the people who were initially on the Lahaina missing persons list turned up in the days following the fire. Tearful reunions ensued.

Two weeks after the fire, the Imperials hoped they’d have the same outcome as they loaded into a truck to check out some exciting news: someone had reported seeing Rafael Sr. at a local church. He’d been eating and had burns on his hands and looked disoriented. The caller said the sighting had occurred three days after the fire. Could he still be in the vicinity?

When the family arrived, they couldn’t confirm the lead.

“We were getting a lot of calls,” Raven says. “There were a lot of rumors saying that they found him.”

None of them panned out. They kept looking.


The scenes following large-scale destructive events like the fires in Paradise and Lahaina can be sprawling and dangerous, with victims sometimes dispersed across a large swath of land if many people died trying to escape. Teams need to meticulously and tediously search mountains of mixed, melted, or burned debris just to find bits of human remains that might otherwise be mistaken for a piece of plastic or drywall. Compounding the challenge is the comingling of remains—from people who died huddled together, or in the same location, or alongside pets or other animals.

This is when the work of forensic anthropologists is essential: they have the skills to differentiate between human and animal bones and to find the critical samples that are needed by DNA specialists, fire and arson investigators, forensic pathologists and dentists, and other experts. Rapid DNA analysis “works best in tandem with forensic anthropologists, particularly in wildfires,” Gin explains.

“The first step is determining, is it a bone?” says Robert Mann, a forensic anthropologist at the University of Hawaii John A. Burns School of Medicine on Oahu. Then, is it a human bone? And if so, which one?

Rober Mann in a lab coat with a human skeleton on the table in front of him
Forensic anthropologist Robert Mann has spent his career identifying human remains.
AP PHOTO/LUCY PEMONI

Mann has served on teams that have helped identify the remains of victims after the terrorist attacks of September 11, 2001, and the 2004 Indian Ocean tsunami, among other mass-casualty events. He remembers how in one investigation he received an object believed to be a human bone; it turned out to be a plastic replica. In another case, he was looking through the wreckage of a car accident and spotted what appeared to be a human rib fragment. Upon closer examination, he identified it as a piece of rubber weather stripping from the rear window. “We examine every bone and tooth, no matter how small, fragmented, or burned it might be,” he says. “It’s a time-consuming but critical process because we can’t afford to make a mistake or overlook anything that might help us establish the identity of a person.”

For Mann, the Maui disaster felt particularly immediate. It was right near his home. He was deployed to Lahaina about a week after the fire, as one of more than a dozen forensic anthropologists on scene from universities in places including Oregon, California, and Hawaii.

While some anthropologists searched the recovery zone—looking through what was left of homes, cars, buildings, and streets, and preserving fragmented and burned bone, body parts, and teeth—Mann was stationed in the morgue, where samples were sent for processing.

It used to be much harder to find samples that scientists believed could provide DNA for analysis, but that’s also changed recently as researchers have learned more about what kind of DNA can survive disasters. Two kinds are used in forensic identity testing: nuclear DNA (found within the nuclei of eukaryotic cells) and mitochondrial DNA (found in the mitochondria, organelles located outside the nucleus). Both, it turns out, have survived plane crashes, wars, floods, volcanic eruptions, and fires.

Theories have also been evolving over the past few decades about how to preserve and recover DNA specifically after intense heat exposure. One 2018 study found that a majority of the samples actually survived high heat. Researchers are also learning more about how bone characteristics change depending on the degree. “Different temperatures and how long a body or bone has been exposed to high temperatures affect the likelihood that it will or will not yield usable DNA,” Mann says.

Typically, forensic anthropologists help select which bone or tooth to use for DNA testing, says Mann. Until recently, he explains, scientists believed “you cannot get usable DNA out of burned bone.” But thanks to these new developments, researchers are realizing that with some bone that has been charred, “they’re able to get usable, good DNA out of it,” Mann says. “And that’s new.” Indeed, Selden explains that “in a typical bad fire, what I would expect is 80% to 90% of the samples are going to have enough intact DNA” to get a result from rapid analysis. The rest, he says, may require deeper sequencing.

The aftermath of large-scale destructive events like the fire in Lahaina can be sprawling and dangerous. Teams need to meticulously search through mountains of mixed, melted, or burned debris to find bits of human remains.
GLENN FAWCETT VIA ALAMY

Anthropologists can often tell “simply by looking” if a sample will be good enough to help create an ID. If it’s been burned and blackened, “it might be a good candidate for DNA testing,” Mann says. But if it’s calcined (white and “china-like”), he says, the DNA has probably been destroyed.

On Maui, Mann adds, rapid DNA analysis made the entire process more efficient, with tests coming back in just two hours. “That means while you’re doing the examination of this individual right here on the table, you may be able to get results back on who this person is,” he says. From inside the lab, he watched the science unfold as the number of missing on Maui quickly began to go down.

Within three days, 42 people’s remains were recovered inside Maui homes or buildings and another 39 outside, along with 15 inside vehicles and one in the water. The first confirmed identification of a victim on the island occurred four days after the fire—this one via fingerprint. The ANDE rapid DNA team arrived two days after the fire and deployed four boxes to analyze multiple samples of DNA simultaneously. The first rapid DNA identification happened within that first week.


Sixteen days

More than two weeks after the fire, the list of missing and unaccounted-for individuals was dwindling, but it still had 388 people on it. Rafael Sr. was one of them.

Raven and Raphael Jr. raced to another location: Cupies café in Kahului, more than 20 miles from Lahaina. Someone had reported seeing him there.

Rafael’s family hung posters around the island, desperately hoping for reliable information. (Phone number redacted by MIT Technology Review.)
ERIKA HAYASAKI

The tip was another false lead.

As family and friends continued to search, they stopped by support hubs that had sprouted up around the island, receiving information about Red Cross and FEMA assistance or donation programs as volunteers distributed meals and clothes. These hubs also sometimes offered DNA testing.

Raven still had a “50-50” feeling that his dad might be out there somewhere. But he was beginning to lose some of that hope.


Gin was stationed at one of the support hubs, which offered food, shelter, clothes, and support. “You could also go in and give biological samples,” she says. “We actually moved one of the rapid DNA instruments into the family assistance center, and we were running the family samples there.” Eliminating the need to transport samples from a site to a testing center further cut down any lag time.

Selden had once believed that the biggest hurdle for his technology would be building the actual device, which took about eight years to design and another four years to perfect. But at least in Lahaina, it was something else: persuading distraught and traumatized family members to offer samples for the test.

Nationally, there are serious privacy concerns when it comes to rapid DNA technology. Organizations like the ACLU warn that as police departments and governments begin deploying it more often, there must be more oversight, monitoring, and training in place to ensure that it is always used responsibly, even if that adds some time and expense. But the space is still largely unregulated, and the ACLU fears it could give rise to rogue DNA databases “with far fewer quality, privacy, and security controls than federal databases.”

Family support centers popped up around Maui to offer clothing, food, and other assistance, and sometimes to take DNA samples to help find missing family members.

In a place like Hawaii, these fears are even more palpable. The islands have a long history of US colonialism, military dominance, and exploitation of the Native population and of the large immigrant working-class population employed in the tourism industry.

Native Hawaiians in particular have a fraught relationship with DNA testing. Under a US law signed in 1921, thousands have a right to live on 200,000 designated acres of land trust, almost for free. It was a kind of reparations measure put in place to assist Native Hawaiians whose land had been stolen. Back in 1893, a small group of American sugar plantation owners and descendants of Christian missionaries, backed by US Marines, held Hawaii’s Queen Lili‘uokalani in her palace at gunpoint and forced her to sign over 1.8 million acres to the US, which ultimately seized the islands in 1898.

Queen Liliuokalani in a formal seated portrait
Hawaii’s Queen Lili‘uokalani was forced to sign over 1.8 million acres to the US.
PUBLIC DOMAIN VIA WIKIMEDIA COMMONS

To lay their claim to the designated land and property, individuals first must prove via DNA tests how much Hawaiian blood they have. But many residents who have submitted their DNA and qualified for the land have died on waiting lists before ever receiving it. Today, Native Hawaiians are struggling to stay on the islands amid skyrocketing housing prices, while others have been forced to move away.

Meanwhile, after the fires, Filipino families faced particularly stark barriers to getting information about financial support, government assistance, housing, and DNA testing. Filipinos make up about 25% of Hawaii’s population and 40% of its workers in the tourism industry. They also make up 46% of undocumented residents in Hawaii—more than any other group. Some encountered language barriers, since they primarily spoke Tagalog or Ilocano. Some worried that people would try to take over their burned land and develop it for themselves. For many, being asked for DNA samples only added to the confusion and suspicion.

Selden says he hears the overall concerns about DNA testing: “If you ask people about DNA in general, they think of Brave New World and [fear] the information is going to be used to somehow harm or control people.” But just like regular DNA analysis, he explains, rapid DNA analysis “has no information on the person’s appearance, their ethnicity, their health, their behavior either in the past, present, or future.” He describes it as a more accurate fingerprint.

Gin tried to help the Lahaina family members understand that their DNA “isn’t going to go anywhere else.” She told them their sample would ultimately be destroyed, something programmed to occur inside ANDE’s machine. (Selden says the boxes were designed to do this for privacy purposes.) But sometimes, Gin realizes, these promises are not enough.

“You still have a large population of people that, in my experience, don’t want to give up their DNA to a government entity,” she says. “They just don’t.”

Kim Gin
Gin understands that family members are often nervous to give their DNA samples. She promises the process of rapid DNA analysis respects their privacy, but she knows sometimes promises aren’t enough.
BRYAN TARNOWSKI

The immediate aftermath of a disaster, when people are suffering from shock, PTSD, and displacement, is the worst possible moment to try to educate them about DNA tests and explain the technology and privacy policies. “A lot of them don’t have anything,” Gin says. “They’re just wondering where they’re going to lay their heads down, and how they’re going to get food and shelter and transportation.”

Unfortunately, Lahaina’s survivors won’t be the last people in this position. Particularly given the world’s current climate trajectory, the risk of deadly events in just about every neighborhood and community will rise. And figuring out who survived and who didn’t will be increasingly difficult. Mann recalls his work on the Indian Ocean tsunami, when over 227,000 people died. “The bodies would float off, and they ended up 100 miles away,” he says. Investigators were at times left with remains that had been consumed by sea creatures or degraded by water and weather. He remembers how they struggled to determine: “Who is the person?”

Mann has spent his own career identifying people including “missing soldiers, sailors, airmen, Marines, from all past wars,” as well as people who have died recently. That closure is meaningful for family members, some of them decades, or even lifetimes, removed.

In the end, distrust and conspiracy theories did in fact hinder DNA-identification efforts on Maui, according to a police department report.


33 days

By the time Raven went to a family resource center to submit a swab, some four weeks had gone by. He remembers the quick rub inside his cheek.

Some of his family had already offered their own samples before Raven provided his. For them, waiting wasn’t an issue of mistrusting the testing as much as experiencing confusion and chaos in the weeks after the fire. They believed Uncle Raffy was still alive, and they still held hope of finding him. Offering DNA was a final step in their search.

“I did it for my mom,” Raven says. She still wanted to believe he was alive, but Raven says: “I just had this feeling.” His father, he told himself, must be gone.

Just a day after he gave his sample—on September 11, more than a month after the fire—he was at the temporary house in Kihei when he got the call: “It was,” Raven says, “an automatic match.”

Raven gave a cheek swab about a month after the disappearance of his father. It didn’t take long for him to get a phone call: “It was an automatic match.”
WINNI WINTERMEYER

The investigators let the family know the address where the remains of Rafael Sr. had been found, several blocks away from their home. They put it into Google Maps and realized it was where some family friends lived. The mother and son of that family had been listed as missing too. Rafael Sr., it seemed, had been with or near them in the end.

By October, investigators in Lahaina had obtained and analyzed 215 DNA samples from family members of the missing. By December, DNA analysis had confirmed the identities of 63 of the most recent count of 101 victims. Seventeen more had been identified by fingerprint, 14 via dental records, and two through medical devices, along with three who died in the hospital. While some of the most damaged remains would still be undergoing DNA testing months after the fires, it’s a drastic improvement over the identification processes for 9/11 victims, for instance—today, over 20 years later, some are still being identified by DNA.

Raphael Imperial Sr
Raven remembers how much his father loved karaoke. His favorite song was “My Way,” by Frank Sinatra. 
COURTESY OF RAVEN IMPERIAL

Rafael Sr. was born on October 22, 1959, in Naga City, the Philippines. The family held his funeral on his birthday last year. His relatives flew in from Michigan, the Philippines, and California.

Raven says in those weeks of waiting—after all the false tips, the searches, the prayers, the glimmers of hope—deep down the family had already known he was gone. But for Evelyn, Raphael Jr., and the rest of their family, DNA tests were necessary—and, ultimately, a relief, Raven says. “They just needed that closure.”

Erika Hayasaki is an independent journalist based in Southern California.

Want less mining? Switch to clean energy.

Political fights over mining and minerals are heating up, and there are growing environmental and sociological concerns about how to source the materials the world needs to build new energy technologies. 

But low-emissions energy sources, including wind, solar, and nuclear power, have a smaller mining footprint than coal and natural gas, according to a new report from the Breakthrough Institute released today.

The report’s findings add to a growing body of evidence that technologies used to address climate change will likely lead to a future with less mining than a world powered by fossil fuels. However, experts point out that oversight will be necessary to minimize harm from the mining needed to transition to lower-emission energy sources. 

“In many ways, we talk so much about the mining of clean energy technologies, and we forget about the dirtiness of our current system,” says Seaver Wang, an author of the report and co-director of Climate and Energy at the Breakthrough Institute, an environmental research center.  

In the new analysis, Wang and his colleagues considered the total mining footprint of different energy technologies, including the amount of material needed for these energy sources and the total amount of rock that needs to be moved to extract that material.

Many minerals appear in small concentrations in source rock, so the process of extracting them has a large footprint relative to the amount of final product. A mining operation would need to move about seven kilograms of rock to get one kilogram of aluminum, for instance. For copper, the ratio is much higher, at over 500 to one. Taking these ratios into account allows for a more direct comparison of the total mining required for different energy sources. 

With this adjustment, it becomes clear that the energy source with the highest mining burden is coal. Generating one gigawatt-hour of electricity with coal requires 20 times the mining footprint as generating the same electricity with low-carbon power sources like wind and solar. Producing the same electricity with natural gas requires moving about twice as much rock.

Tallying up the amount of rock moved is an imperfect approximation of the potential environmental and sociological impact of mining related to different technologies, Wang says, but the report’s results allow researchers to draw some broad conclusions. One is that we’re on track for less mining in the future. 

Other researchers have projected a decrease in mining accompanying a move to low-emissions energy sources. “We mine so many fossil fuels today that the sum of mining activities decreases even when we assume an incredibly rapid expansion of clean energy technologies,” Joey Nijnens, a consultant at Monitor Deloitte and author of another recent study on mining demand, said in an email.

That being said, potentially moving less rock around in the future “hardly means that society shouldn’t look for further opportunities to reduce mining impacts throughout the energy transition,” Wang says.

There’s already been progress in cutting down on the material required for technologies like wind and solar. Solar modules have gotten more efficient, so the same amount of material can yield more electricity generation. Recycling can help further cut material demand in the future, and it will be especially crucial to reduce the mining needed to build batteries.  

Resource extraction may decrease overall, but it’s also likely to increase in some places as our demands change, researchers pointed out in a 2021 study. Between 32% and 40% of the mining increase in the future could occur in countries with weak, poor, or failing resource governance, where mining is more likely to harm the environment and may fail to benefit people living near the mining projects. 

“We need to ensure that the energy transition is accompanied by responsible mining that benefits local communities,” Takuma Watari, a researcher at the National Institute for Environmental Studies and an author of the study, said via email. Otherwise, the shift to lower-emissions energy sources could lead to a reduction of carbon emissions in the Global North “at the expense of increasing socio-environmental risks in local mining areas, often in the Global South.” 

Strong oversight and accountability are crucial to make sure that we can source minerals in a responsible way, Wang says: “We want a rapid energy transition, but we also want an energy transition that’s equitable.”

How to build a thermal battery

This article is from The Spark, MIT Technology Review’s weekly climate newsletter. To receive it in your inbox every Wednesday, sign up here.

The votes have been tallied, and the results are in. The winner of the 11th Breakthrough Technology, 2024 edition, is … drumroll please … thermal batteries! 

While the editors of MIT Technology Review choose the annual list of 10 Breakthrough Technologies, in 2022 we started having readers weigh in on an 11th technology. And I don’t mean to flatter you, but I think you picked a fascinating one this year. 

Thermal energy storage is a convenient way to stockpile energy for later. This could be crucial in connecting cheap but inconsistent renewable energy with industrial facilities, which often require a constant supply of heat. 

I wrote about why this technology is having a moment, and where it might wind up being used, in a story published Monday. For the newsletter this week, let’s take a deeper look at the different kinds of thermal batteries out there, because there’s a wide world of possibilities. 

Step 1: Choose your energy source

In the journey to build a thermal battery, the crucial first step is to choose where your heat comes from. Most of the companies I’ve come across are building some sort of power-to-heat system, meaning electricity goes in and heat comes out. Heat often gets generated by running a current through a resistive material in a process similar to what happens when you turn on a toaster.

Some projects may take electricity directly from sources like wind turbines or solar panels that aren’t hooked up to the grid. That could reduce energy costs, since you don’t have to pay surcharges built into grid electricity rates, explains Jeffrey Rissman, senior director of industry at Energy Innovation, a policy and research firm specializing in energy and climate. 

Otherwise, thermal batteries can be hooked up to the grid directly. These systems could allow a facility to charge up when electricity prices are low or when there’s a lot of renewable energy on the grid. 

Some thermal storage systems are soaking up waste heat rather than relying on electricity. Brenmiller Energy, for example, is building thermal batteries that can be charged up with heat or electricity, depending on the customer’s needs. 

Depending on the heat source, systems using waste heat may not be able to reach temperatures as high as their electricity-powered counterparts, but they could help increase the efficiency of facilities that would otherwise waste that energy. There’s especially high potential for high-temperature processes, like cement and steel production. 

Step 2: Choose your storage material

Next up: pick out a heat storage medium. These materials should probably be inexpensive and able to reach and withstand high temperatures. 

Bricks and carbon blocks are popular choices, as they can be packed together and, depending on the material, reach temperatures well over 1,000 °C (1,800 °F). Rondo Energy, Antora Energy, and Electrified Thermal Solutions are among the companies using blocks and bricks to store heat at these high temperatures. 

Crushed-up rocks are another option, and the storage medium of choice for Brenmiller Energy. Caldera is using a mixture of aluminum and crushed rock. 

Molten materials can offer even more options for delivering thermal energy later, since they can be pumped around (though this can also add more complexity to the system). Malta is building thermal storage systems that use molten salt, and companies like Fourth Power are using systems that rely in part on molten metals. 

Step 3: Choose your delivery method

Last, and perhaps most important, is deciding how to get energy back out of your storage system. Generally, thermal storage systems can deliver heat, use it to generate electricity, or go with some combination of the two. 

Delivering heat is the most straightforward option. Typically, air or another gas gets blown over the hot thermal storage material, and that heated gas can be used to warm up equipment or to generate steam. 

Some companies are working to use heat storage to deliver electricity instead. This could allow thermal storage systems to play a role not only in industry but potentially on the electrical grid as an electricity storage solution. One downside? These systems generally take a hit on efficiency, the amount of energy that can be returned from storage. But they may be right for some situations, such as facilities that need both heat and electricity on demand. Antora Energy is aiming to use thermophotovoltaic materials to turn heat stored in its carbon blocks back into electricity. 

Some companies plan to offer a middle path, delivering a combination of heat and electricity, depending on what a facility needs. Rondo Energy’s heat batteries can deliver high-pressure steam that can be used either for heating alone or to generate some electricity using cogeneration units. 

The possibilities are seemingly endless for thermal batteries, and I’m seeing new players with new ideas all the time. Stay tuned for much more coverage of this hot technology (sorry, I had to). 


Now read the rest of The Spark

Related reading

Read more about why thermal batteries won the title of 11th breakthrough technology in my story from Monday.

I first wrote about heat as energy storage in this piece last year. As I put it then: the hottest new climate technology is bricks. 

Companies have made some progress in scaling up thermal batteries—our former fellow June Kim wrote about one new manufacturing facility in October.

VIRGINIA HANUSIK

Another thing

The state of Louisiana in the southeast US has lost over a million acres of its coast to erosion. A pilot project aims to save some homes in the state by raising them up to avoid the worst of flooding. 

It’s an ambitious attempt to build a solution to a crisis, and the effort could help keep communities together. But some experts worry that elevation projects offer too rosy an outlook and think we need to focus on relocation instead. Read more in this fascinating feature story from Xander Peters.

Keeping up with climate  

It can be easy to forget, but we’ve actually already made a lot of progress on addressing climate change. A decade ago, the world was on track for about 3.7 °C of warming over preindustrial levels. Today, it’s 2.7 °C with current actions and policies—higher than it should be but lower than it might have been. (Cipher News)

We’re probably going to have more batteries than we actually need for a while. Today, China alone makes enough batteries to satisfy global demand, which could make things tough for new players in the battery game. (Bloomberg

2023 was a record year for wind power. The world installed 117 gigawatts of new capacity last year, 50% more than the year before. (Associated Press)

Here’s what’s coming next for offshore wind. (MIT Technology Review)

Coal power grew in 2023, driven by a surge of new plants coming online in China and a slowdown of retirements in Europe and the US. (New York Times)

People who live near solar farms generally have positive feelings about their electricity-producing neighbors. There’s more negative sentiment among people who live very close to the biggest projects, though. (Inside Climate News)

E-scooters have been zipping through city streets for eight years, but they haven’t exactly ushered in the zero-emissions micro-mobility future that some had hoped for. Shared scooters can cut emissions, but it all depends on rider behavior and company practices. (Grist)

The grid could use a renovation. Replacing existing power lines with new materials could double grid capacity in many parts of the US, clearing the way for more renewables. (New York Times

The first all-electric tugboat in the US is about to launch in San Diego. The small boats are crucial to help larger vessels in and around ports, and the fossil-fuel-powered ones are a climate nightmare. (Canary Media)