Holistic climate justice: The guidelines recognize that geoengineering won’t affect just those people currently residing on Earth, but on future generations as well. Some methods, like stratospheric aerosols, don’t eliminate the risks caused by warming, but shift them onto future generations, who will face sudden and potentially dramatic warming if the geoengineering is ever stopped. Others may cause regional differences in either benefits or warming, shifting consequences to different populations.
Special attention should be paid to those who have historically been on the wrong side of environmental problems in the past. And harms to nature need to be considered as well.
Inclusive public participation: The research shouldn’t be approached as simply a scientific process; instead, any affected communities should be included in the process, and informed consent should be obtained from them. There should be ongoing public engagement with those communities and adapt to their cultural values.
Transparency: The public needs to be aware of who’s funding any geoengineering research and ensure that whoever’s providing the money doesn’t influence decisions regarding the design of the research. Those decisions, and the considerations behind them, should also be made clear to the public.
Informed governance: Any experiments have to conform to laws ranging from local to international. Any research programs should be approved by an independent body before any work starts. All the parties involved—and this could include the funders, the institutions, and outside contractors—should be held accountable to governments, public institutions, and those who will potentially be impacted by the work.
If you think this will make pursuing this research considerably more complicated, you are absolutely correct. But again, even tests of these approaches could have serious environmental consequences. And many of these things represent best practices for any research with potential public consequences; the fact that they haven’t always been pursued is not an excuse to continue to avoid doing them.
On Friday, the US Court of Appeals for the DC Circuit denied a request to put a hold on recently formulated rules that would limit carbon emissions made by fossil fuel power plants. The request, made as part of a case that sees 25 states squaring off against the EPA, would have put the federal government’s plan on hold while the case continued. Instead, the EPA will be allowed to continue the process of putting its rules into effect, and the larger case will be heard under an accelerated schedule.
Here we go again
The EPA’s efforts to regulate carbon emissions from power plants go back all the way to the second Bush administration, when a group of states successfully sued the EPA to force it to regulate greenhouse gas emissions. This led to a formal endangerment finding regarding greenhouse gases during the Obama administration, something that remained unchallenged even during Donald Trump’s term in office.
Obama tried to regulate emissions through the Clean Power Plan, but his second term came to an end before this plan had cleared court hurdles, allowing the Trump administration to formulate a replacement that did far less than the Clean Power Plan. This took place against a backdrop of accelerated displacement of coal by natural gas and renewables that had already surpassed the changes envisioned under the Clean Power Plan.
In any case, the Trump plan was thrown out by the courts on the day before Biden’s administration, allowing his EPA to start with a clean slate. Biden’s original plan, which would have had states regulate emissions from their electric grids by regulating them as a single system, was thrown out by the Supreme Court, which ruled that emissions would need to be regulated on a per-plant basis in a decision termed West Virginia v. EPA.
So, that’s what the agency is now trying to do. Its plan, issued last year, would allow fossil-fuel-burning plants that are being shut down in the early 2030s to continue operating without restrictions. Others will need to either install carbon capture equipment, or natural gas plants could swap in green hydrogen as their primary fuel.
And again
In response, 25 states have sued to block the rule (you can check out this filing to see if yours is among them). The states also sought a stay that would prevent the rule from being implemented while the case went forward. In it, they argue that carbon capture technology isn’t mature enough to form the basis of these regulations (something we predicted was likely to be a point of contention). The suit also suggests that the rules would effectively put coal out of business, something that’s beyond the EPA’s remit.
The DC Court of Appeals, however, was not impressed, ruling that the states’ arguments regarding carbon capture are insufficient: “Petitioners have not shown they are likely to succeed on those claims given the record in this case.” And that’s the key hurdle for determining whether a stay is justified. And the regulations don’t pose a likelihood of irreparable harm, as the court notes that states aren’t even expected to submit a plan for at least two years, and the regulations won’t kick in until 2030 at the earliest.
Meanwhile, the states cited the Supreme Court’s West Virginia v. EPA decision to argue against these rules, suggesting they represent a “major question” that requires input from Congress. The Court was also not impressed, writing that “EPA has claimed only the power to ‘set emissions limits under Section 111 based on the application of measures that would reduce pollution by causing the regulated source to operate more cleanly,’ a type of conduct that falls well within EPA’s bailiwick.”
To respond to the states’ concerns about the potential for irreparable harm, the court plans to consider them during the 2024 term and has given the parties just two weeks to submit proposed schedules for briefings on the case.
Enlarge/ Bioreactors that host algae would be one option for carbon sequestration—as long as the carbon is stored somehow.
More than 200 kilometers off Norway’s coast in the North Sea sits the world’s first offshore carbon capture and storage project. Built in 1996, the Sleipner project strips carbon dioxide from natural gas—largely made up of methane—to make it marketable. But instead of releasing the CO2 into the atmosphere, the greenhouse gas is buried.
The effort stores around 1 million metric tons of CO2 per year—and is praised by many as a pioneering success in global attempts to cut greenhouse gas emissions.
Last year, total global CO2 emissions hit an all-time high of around 35.8 billion tons, or gigatons. At these levels, scientists estimate, we have roughly six years left before we emit so much CO2 that global warming will consistently exceed 1.5° Celsius above average preindustrial temperatures, an internationally agreed-upon limit. (Notably, the global average temperature for the past 12 months has exceeded this threshold.)
Phasing out fossil fuels is key to cutting emissions and fighting climate change. But a suite of technologies collectively known as carbon capture, utilization and storage, or CCUS, are among the tools available to help meet global targets to cut CO2 emissions in half by 2030 and to reach net-zero emissions by 2050. These technologies capture, use or store away CO2 emitted by power generation or industrial processes, or suck it directly out of the air. The Intergovernmental Panel on Climate Change (IPCC), the United Nations body charged with assessing climate change science, includes carbon capture and storage among the actions needed to slash emissions and meet temperature targets.
Enlarge/ Carbon capture, utilization and storage technologies often capture CO2 from coal or natural gas power generation or industrial processes, such as steel manufacturing. The CO2 is compressed into a liquid under high pressure and transported through pipelines to sites where it may be stored, in porous sedimentary rock formations containing saltwater, for example, or used for other purposes. The captured CO2 can be injected into the ground to extract oil dregs or used to produce cement and other products.
Governments and industry are betting big on such projects. Last year, for example, the British government announced 20 billion pounds (more than $25 billion) in funding for CCUS, often shortened to CCS. The United States allocated more than $5 billion between 2011 and 2023 and committed an additional $8.2 billion from 2022 to 2026. Globally, public funding for CCUS projects rose to $20 billion in 2023, according to the International Energy Agency (IEA), which works with countries around the world to forge energy policy.
Given the urgency of the situation, many people argue that CCUS is necessary to move society toward climate goals. But critics don’t see the technology, in its current form, shifting the world away from oil and gas: In a lot of cases, they point out, the captured CO2 is used to extract more fossil fuels in a process known as enhanced oil recovery. They contend that other existing solutions such as renewable energy offer deeper and quicker CO2 emissions cuts. “It’s better not to emit in the first place,” says Grant Hauber, an energy finance adviser at the Institute for Energy Economics and Financial Analysis, a nonpartisan organization in Lakewood, Ohio.
What’s more, fossil fuel companies provide funds to universities and researchers—which some say could shape what is studied and what is not, even if the work of individual scientists is legitimate. For these reasons, some critics say CCUS shouldn’t be pursued at all.
“Carbon capture and storage essentially perpetuates fossil fuel reliance. It’s a distraction and a delay tactic,” says Jennie Stephens, a climate justice researcher at Northeastern University in Boston. She adds that there is little focus on understanding the psychological, social, economic, and political barriers that prevent communities from shifting away from fossil fuels and forging solutions to those obstacles.
According to the Global CCS Institute, an industry-led think tank headquartered in Melbourne, Australia, of the 41 commercial projects operational as of July 2023, most were part of efforts that produce, extract, or burn fossil fuels, such as coal- and gas-fired power plants. That’s true of the Sleipner project, run by the energy company Equinor. It’s the case, too, with the world’s largest CCUS facility, operated by ExxonMobil in Wyoming, in the United States, which also captures CO2 as part of the production of methane.
Granted, not all CCUS efforts further fossil fuel production, and many projects now in the works have the sole goal of capturing and locking up CO2. Still, some critics doubt whether these greener approaches could ever lock away enough CO2 to meaningfully contribute to climate mitigation, and they are concerned about the costs.
Others are more circumspect. Sally Benson, an energy researcher at Stanford University, doesn’t want to see CCUS used as an excuse to carry on with fossil fuels. But she says the technology is essential for capturing some of the CO2 from fossil fuel production and usage, as well as from industrial processes, as society transitions to new energy sources. “If we can get rid of those emissions with carbon capture and sequestration, that sounds like success to me,” says Benson, who codirects an institute that receives funding from fossil fuel companies.
Enlarge/ Fungus samples are seen on display inside the Fungarium at the Royal Botanic Gardens in Kew, west London in 2023. The Fungarium was founded in 1879 and holds an estimated 380,000 specimens from the UK.
It’s hard to miss the headliners at Kew Gardens. The botanical collection in London is home to towering redwoods and giant Amazonian water lilies capable of holding up a small child. Each spring, its huge greenhouses pop with the Technicolor displays of multiple orchid species.
But for the really good stuff at Kew, you have to look below the ground. Tucked underneath a laboratory at the garden’s eastern edge is the fungarium: the largest collection of fungi anywhere in the world. Nestled inside a series of green cardboard boxes are some 1.3 million specimens of fruiting bodies—the parts of the fungi that appear above ground and release spores.
“This is basically a library of fungi,” says Lee Davies, curator of the Kew fungarium. “What this allows us to do is to come up with a reference of fungal biodiversity—what fungi are out there in the world, where you can find them.” Archivists—wearing mushroom hats for some reason—float between the shelves, busily digitizing the vast archive, which includes around half of all the species known to science.
Enlarge/ Fungarium Collections Manager Lee Davies inspects a fungus sample stored within the Fungarium at the Royal Botanic Gardens in Kew, west London in 2023.
In the hierarchy of environmental causes, fungi have traditionally ranked somewhere close to the bottom, Davies says. He himself was brought to the fungarium against his will. Davies was working with tropical plants when a staffing reshuffle brought him to the temperature-controlled environs of the fungarium. “They moved me here in 2014, and it’s amazing. Best thing ever, I love it. It’s been a total conversion.”
Davies’ own epiphany echoes a wider awakening of appreciation for these overlooked organisms. In 2020, mycologist Merlin Sheldrake’s book Entangled Life: How Fungi Make Our Worlds, Change Our Minds, and Shape Our Futures was a surprise bestseller. In the video game and HBO series The Last of Us, it’s a fictional brain-eating fungus from the genus Cordyceps that sends the world into an apocalyptic spiral. (The Kew collection includes a tarantula infected with Cordyceps—fungal tendrils reach out from the soft gaps between the dead insect’s limbs.)
While the wider world is waking up to these fascinating organisms, scientists are getting to grips with the crucial role they play in ecosystems. In a laboratory just above the Kew fungarium, mycologist Laura Martinez-Suz studies how fungi help sequester carbon in the soil, and why some places seem much better at storing soil carbon than others.
Soil is a huge reservoir of carbon. There are around 1.5 trillion tons of organic carbon stored in soils across the world—about twice the amount of carbon in the atmosphere. Scientists used to think that most of this carbon entered the soil when dead leaves and plant matter decomposed, but it’s now becoming clear that plant roots and fungi networks are a critical part of this process. One study of forested islands in Sweden found that the majority of carbon in the forest soil actually came from root-fungi networks, not plant matter fallen from above the ground.
Mary Yap has spent the last year and a half trying to get farmers to fall in love with basalt. The volcanic rock is chock full of nutrients, captured as its crystal structure forms from cooling magma, and can make soil less acidic. In that way it’s like limestone, which farmers often use to improve their soil. It’s a little more finicky to apply, and certainly less familiar. But basalt also comes with an important side benefit: It can naturally capture carbon from the atmosphere.
Yap’s pitch is part of a decades-long effort to scale up that natural weathering process and prove that it can lock carbon away for long enough to make a different to the climate. “The bottleneck is getting farmers to want to do this,” Yap says.
On Thursday, Yap’s young startup, Lithos Carbon, got a $57.1 million boost for its quest to turn basalt dust into a viable climate solution. It came from Frontier, a benefit corporation backed by a consortium of companies aiming to finance promising approaches to carbon dioxide removal, or CDR. Lithos says it will use the funds to soak up 154,000 tons of CO2 by 2028, by sprinkling basalt dust on thousands of acres of US farmland. The average US car emits about 4 tons of CO2 each year.
The carbon removal purchase is the largest yet by Frontier, which was formed last year with nearly $1 billion from its tech-dominated members. Many of those companies, which include Meta, Alphabet, and payments processor Stripe, which owns Frontier, have made climate pledges that require not only reducing the emissions from their operations and supply chains but also “negative emissions”—sucking up carbon from the atmosphere to cancel out other emissions.
That accounting trick has been easier to prove out on paper than in practice. Many companies would have once turned to buying carbon offsets from activities like protecting forests that would otherwise be felled. But some have been trying to move away from those scandal-plagued and often short-lived approaches and into more durable techniques for carbon removal.
The current options for companies seeking negative emissions are limited. Frontier’s purchases are essentially down payments on ideas that are still in their infancy—generally too hard to verify or too expensive, or both, to attract a significant customer base. “What we’re trying to evaluate the field on is whether it’s on the trajectory to get to climate-relevant scale,” says Nan Ransohoff, who leads Frontier and also climate work at Stripe. The group starts with small “prepurchases” meant to help promising startups, and then moves on to “offtake” agreements for larger amounts of carbon that its members can count toward their emissions goals.
The Lithos purchase is one of those larger deals. It prices carbon removals at $370 per ton, about a quarter of which will pay for field monitoring and modeling to verify that carbon is being sequestered away from the atmosphere for the long term. Ransohoff says Frontier believes that Lithos is on a path to its goal of removing CO2 for customers at a cost of less than $100 per ton, and at a rate of at least a half a billion tons per year.
“Most promising” approach
Lithos, founded in 2022, is developing a technology called enhanced rock weathering. It involves spreading a fine dust of basalt across fields before planting. As the rock further weathers from rainfall, it reacts with CO2 in the air. That forms bicarbonate, which locks away the carbon by combining it with hydrogen and oxygen atoms. Ultimately, the compound is washed into the ocean, where the carbon should stay put.
The strategy has the benefit of piggybacking on things that humans already do, Yap says. That’s in contrast with techniques like direct air capture, which involves building industrial plants that suck carbon out of the atmosphere. It’s easy to measure carbon removed that way—it’s all captured there onsite—but critics say it will be difficult to scale up because removing enough carbon to make a difference will require thousands of dedicate, resource-intensive facilities.
Using basalt dust to capture carbon should be more easily scaled up. There are plenty of fields to dump rock dust onto, and plenty of water for carbon to end up in. But the distributed nature of the process also makes measuring how much carbon was actually removed from the atmosphere more difficult.
