The problem with playing God to fix the climate: It might not work

 

THE ROAD TO COP26

The problem with playing God to fix the climate: It might not work

 

Cutting emissions alone isn’t enough to bring global warming under control, and that’s spurring interest in geoengineering.

 

Illustration by Kumé Pather for POLITICO

BY KARL MATHIESEN

September 1, 2021 12:42 pm

https://www.politico.eu/article/climate-change-global-warming-ipcc-geoengineering-technology/

 

Climate scientists have a bleak new message: The world has almost certainly failed to limit global warming to 1.5 degrees and is on track for even steeper temperature increases.

 

That means interventions into the planet's largest and most basic functions — lumped under the term geoengineering and considered by many to be unethical, weird or dangerous — may now be the only way to limit warming.

 

“It's a scary prospect, I will totally admit that. But climate change is also scary,” said Ben Kravitz, an assistant professor of earth and atmospheric sciences at Indiana University Bloomington in the U.S.

 

Last month the U.N.'s Intergovernmental Panel on Climate Change (IPCC) report grimly described a future in which heat, drought, floods and fires worsen as the world drifts past 1.5 degrees sometime in the next 20 years; even the most optimistic emissions cutting scenario foresees that temperatures will cap out well above 2 degrees.

 

Even if the world stops adding greenhouse gases, the climate doesn’t just mellow out on its own. “When we stabilize global temperatures, that's our new climate that we have chosen to live in,” said Ed Hawkins, one of the authors of the report.

 

Getting to the relative safety of 1.5 degrees — something governments promised to try to achieve in the 2015 Paris Agreement — means humanity will need to cool the planet back down. There are two ways to do this: Remove carbon from the atmosphere or stop some of the sun’s radiation from warming the earth’s surface.

 

“We have no carbon budget left, we have to remove greenhouse gases from the atmosphere … [and] we need to repair parts of the global system that have gone past their tipping point,” said David King, former U.K. chief scientist and the founder and chair of the Centre for Climate Repair at Cambridge University.

 

Suggested techniques range from planting trees on a monumental scale and better managing soil to store more carbon to ideas that sound like playing God — brightening clouds, changing the chemistry of the ocean or shooting particles into the atmosphere to dim the light of the sun.

 

Those ideas make a lot of people very uncomfortable. There's the Frankenstein problem — the prospect of people tinkering with planetary systems they don't fully understand to create an even greater catastrophe. Then there's the ethical dilemma of a technological quick fix taking the pressure off politicians or companies to cut greenhouse gas pollution as fast as possible.

 

An even greater concern voiced by experts is that geoengineering — humanity's last resort — may not work well enough to spare us.

 

“Geoengineering won’t reverse climate change,” said Kravitz. “It might get some of the things pretty close. Some other things maybe not.”

 

A problematic concept

Efforts to quell climate change have focused on cutting emissions, which made geoengineering anathema to many. Even many scientists are leery of the stigma attached to the term.

 

King thinks only the most extreme forms of intervention in blocking the sun by spraying particles into the sky should be classed as geoengineering. Other methods, like brightening clouds, are "simply imitating natural processes," he said.

 

 

Kravitz, who studies solar radiation modification, thinks carbon dioxide removal doesn’t really count as geoengineering.

 

Other the other hand, David Keller, a specialist in CO2 removal from the GEOMAR Helmholtz Center for Ocean Research in Kiel, Germany, says even tree planting of the type and scale that can really make a difference to the global temperature would be a profoundly unnatural process.

 

Scientists have split into two camps — carbon dioxide removal researchers and those looking at solar radiation modification. “They are very different technologies,” said Keller, but “then there's also been a big philosophical difference.”

 

Every option has drawbacks.

 

Expanding forests is limited by the amount of viable land and the need to use some of it to feed people. Dark trees also soak in more heat. Like forests, carbon stored in the soil isn’t locked away permanently. One change of government policy, a fire or a rogue landowner might destroy years of work.

 

Enhanced weathering, in which crushed rock is spread over the land to speed natural reactions between minerals, water and airborne carbon dioxide, has limited potential because of available land, rock and money, the European Academies’ Science Advisory Council (EASAC) said in a detailed assessment in 2018. Fertilizing the oceans might allow carbon-absorbing plankton to bloom, but could damage a vital ecosystem and food source.

 

More hardcore technological measures for drawing carbon from the atmosphere include bioenergy or direct air capture in which the carbon waste is locked away in geological formations deep underground. But they “rely on carbon capture and storage technology being in place,” said Keller.

 

Governments and energy companies hope to be able to catch and store carbon from industrial chimneys, but the technology has not convinced researchers it can reach the scale and cost needed to squirrel away billions of tons of carbon each year. “That field of science is very far behind,” Keller said.

 

Direct air capture is making some halting steps toward being a commercial business. Climeworks, a company based in Switzerland, last week announced a €1 million a year, 10-year deal to help insurer Swiss Re soak up some of its extra emissions at a plant in Iceland. But the economics don't yet work. Last year, Climeworks told POLITICO it costs around €1,000 to remove 1 ton of carbon dioxide; the current price of a ton of CO2 on the EU's carbon market is about €60. The company hopes to lower its price to €100 per ton by 2030.

 

There may be no 'silver bullet'

The concern shared by scientists is that none of these technologies appear to be able to go big enough to manage a large temperature overshoot — exactly what the world is currently on track for.

 

“There doesn't appear to be a silver bullet,” said Keller, the CO2 removal expert. “I think we can probably accomplish some level of carbon dioxide removal … but whether or not that can be scaled up to remove the necessary amount of CO2, I am not sure.”

 

The European Academies’ Science Advisory Council concluded carbon dioxide removal technologies had “limited realistic potential” of laundering billions of tons of carbon from the atmosphere each year — the scale required by all future scenarios considered by the IPCC.

 

“There's no clear winner,” said Glen Peters, research director of the Center for International Climate and Environmental Research in Oslo, Norway.

 

That's why scientists like Kravitz are calling for more research.

 

“I don't know anyone in this field, who is really enthusiastic about geoengineering. I think we would all rather greenhouse gas mitigation gets ramped up in sufficient time,” he said.

 

King is adamant that at least one of these measures — brightening clouds with seawater droplets so they reflect more sunlight, in turn helping to refreeze the Arctic sea ice — is now “imperative.” The reflective ice in turn would help slow down the heat in the fastest-warming area on the planet.

 

But Kravitz says we are a long way from knowing enough about the knock-on effects. It sounds innocuous, even natural, he said: “Oh, you're just injecting salt into clouds over the ocean. Nobody lives over the ocean, and they've got salt in them anyway, what's the harm of that?” But according to one model, touching up the clouds could cause the Amazon to wither and die. “Which is anything but harmless,” he said.

 

When asked if there is a solar radiation modification that he thinks is most viable, Kravitz backs the one that instinctively terrifies many people: The injection of particles into the stratosphere to dull the light of the sun.

 

"It's basically mimicking a volcanic eruption ... so we kind of know what happens there," he said. "That one would probably work." But the results are likely to be mixed across the world, he said. And when it comes to the climate change impacts such as heat waves, floods, food security and water security, Kravitz’s models remain silent.

 

Ethical questions

Much of the debate around geoengineering is heightened by a sense of unease about its ethical or political implications.

 

A Harvard University balloon launch, planned for this summer in Sweden, would have scattered a few handfuls of calcium carbonate dust 20 kilometers above the surface of the earth to study how they behaved. But it was postponed indefinitely in March thanks to public opposition, in particular from local Sámi indigenous groups. Why study something that “seems to be too dangerous to ever be used?” asked a coalition of NGOs, including Greenpeace.

 

Those who study it say it makes sense to know what all the options are.

 

King said there should be a U.N. moratorium on using stratospheric aerosol injection — as it is known — at scale. But that should allow for research. "Because there may come a point in time when we have failed with every other effort to manage our future."

 

Field experiments will be the only way to know if we can do that successfully, said Kravitz.

 

“Quite frankly, I don't know whether it's a good or bad idea. But people definitely want to know more," Kravitz said. "And, honestly, I think that's healthy. I think if people are going to make a decision about whether geoengineering should be done, I'd really like that decision to be well informed.”

 

Zia Weise contributed reporting.