Geoengineering has been a topic on the fringe of climate discussions for more than a decade, but it’s been edging ever closer to the mainstream as carbon pollution rises.
It’s slated to take a step closer still later this year, with a group of Harvard scientists planning a small scale experiment. Their test will redirect the sun’s rays back into space as part of a larger research program aimed at understanding the benefits and risks of geoengineering the planet to have a cooler climate.
The scientists are focused not only on the climate but also on the policy realm. The project is pushing the once taboo idea of intentionally altering the climate to the forefront of discussions about how humanity can cope with the increasing risks from climate change.
“Solar radiation management is a topic that looks like adaptation looked like in the 1990s,” Gernot Wagner, an economist at Harvard working on the new project, said. “There were some traditional environmentalists in the 1990s who said thou shalt not talk about adaptation because it will detract from the need to mitigate. That has changed a lot.”
Wagner and his colleagues plan to take to the Tucson desert sometime in the next year. There, they’ll release a high-altitude balloon outfitted with sensors that will find its way into the stratosphere, more than 7 miles above the earth’s surface.
Once there, it will spray a fine mist of highly reflective particulate matter that would reflect sunlight back into space. Less energy coming into the earth’s system means there’s less to be trapped by the carbon dioxide-laden atmosphere and thus, less warming.
The sensors would measure the reflectiveness of the particles and how they behave in the stratosphere, providing some of the first real world data. That’s crucial for scientists who currently rely on lab tests and computer models to understand the impacts of solar radiation management. It could be the first of many test flights to gather as much data as possible, improving predictions of what would happen if this type of project was implemented at a regional or even global scale.
Wagner and his colleagues hope their project will break down barriers to considering geoengineering, though he stressed that the project is not endorsing doing large-scale solar radiation management. The effort comes at a time, though, when the world is being forced to cope with the realities of climate change like never before.
Humans have unintentionally been altering the climate by dumping carbon dioxide into the atmosphere for centuries. But the impacts are becoming more clear with each passing day. The world had its hottest year on record in 2016 for the third year in a row. It also breached the 1.5°C (2.7°F) threshold for a few months last year, a crucial milestone for small island states and particularly vulnerable nations.
With only a few decades until humanity burns through the carbon budget that would send the world sailing past its main climate goal of keeping warming below 2°C (3.6°F), Wagner said it’s important to consider alternatives in case the clean energy revolution falters or climate change becomes too much to bear.
The balloon experiment is the splashy part of the program. It feels a bit like an episode of the British science fiction show “Black Mirror”, with scientists performing a test that could both help combat climate change and lead to a raft of new problems.
“When I talk about solar radiation management, it is not putting the climate backward to an earlier state,” David Titley, the director of Penn State’s Center for Solutions to Weather and Climate Risk, said. “It’s one that puts it sideways into a new state that we haven’t fully thought about.”
The idea of altering the atmosphere intentionally inspires fear and discomfort in many researchers and policymakers.
Wagner likened it to the trolley problem, a thought experiment where there’s a runaway trolley and you’re standing by the track switch level. If you don’t pull it, the trolley will run over five people on the tracks ahead. If you do, you’ll switch the trolley to a different set of tracks but kill one person on those tracks.
In the case of geoengineering, we’d have to make an active choice to pull the lever. In doing so, it could unleash a host of consequences, that while less bad than runaway climate change, would still harm people, divert funds from other beneficial projects or have unintended impacts.
Only two known solar radiation management experiments have ever been implemented, one in California and the other in Russia in 2011 and 2009, respectively. A third was scuttled in the U.K. in 2012 after public outcry.
That’s a big reason why the new Harvard program has a less splashy but equally important component to study how geoengineering could impact not just the climate but climate action.
There’s a concern, for example, that geoengineering the planet to a cooler state could stall climate action because the global average temperature is the benchmark for the world’s main climate goal. That would be bad news for ocean acidification, which would continue unabated, and in some ways potentially hook us on geoengineering for a longer period of time, further raising the risk of unintended consequences.
There’s also the risk that undertaking geoengineering could divert money from climate adaptation or improving clean energy technology.
“Something like solar geoengineering is comparatively cheap,” Holly Buck, a PhD candidate studying the social impacts of geoengineering in the Arctic at Cornell, said. “There are a bunch of costs besides operation costs, though. Is it better than spending money on a war in Iraq? Sure. But is it better than putting it into adaptation? I don’t know.”
Buck also said that some people in the Arctic are concerned about bearing a disproportionate amount of the environmental burden from contaminants falling back to earth, due to past experiences with environmental contaminants.
Understanding these and other concerns about geoengineering are just as important to the Harvard researchers and the high-profile people and groups funding their research, including Bill Gates, the Hewlett Foundation and Alfred P. Sloan Foundation.
Ultimately, Wagner said the goal isn’t to turn the project into a full-time geoengineering operation, but to provide policymakers with clear, level-headed information about a topic that stirs up some of our most basic emotions.
“Here’s a controversial topic that’s controversial for a good reason,” he said. “Fear is healthy when it comes to this topic. Fear of climate risk is healthy, too. Let’s put this into context and calibrate that within the context of existing climate risk.”