Carbon dioxide emissions are rising so fast that some scientists are seriously considering putting Earth on life support as a last resort. But what is geoengineering, and is this potential solution worse than the problem?
As climate change intensifies, policymakers, climate scientists, and members of the Intergovernmental Panel on Climate Change (IPCC) have suggested novel methods to counteract harmful trends. These climate intervention techniques are referred to as geoengineering.
So, what is geoengineering, and what does it aim to achieve?
Geoengineering is a form of climate engineering or human climate intervention aimed at modifying long-term trends in Earth’s climate. Current geoengineering proposals primarily focus on two areas: reversing global warming and removing atmospheric carbon dioxide.
In theory, large-scale geoengineering projects could attempt to alter any aspect of Earth’s ecosystems or climate system, potentially addressing global warming effects, ocean acidification, melting polar ice, or volcanic eruptions that breach the Earth’s surface.
Most geoengineering efforts aim to mitigate the negative impacts of industrial activity on Earth’s climate. For instance, greenhouse gases such as carbon dioxide (CO2) and methane (CH4) are increasing in the atmosphere and stratosphere due to deforestation and fossil fuel combustion.
To address atmospheric carbon accumulation, resource conservation, and emission reduction are essential. However, geoengineering proposes to actively remove greenhouse gases from the atmosphere and stratosphere.
Despite its potential benefits, some argue that this planetary fix might be more harmful than the initial problem. There are even calls to remove it from higher education curricula.
In April 2024, researchers from the University of Washington conducted the nation’s first field test of solar geoengineering by dispersing sea salt particles into the air off the California coast. The idea was that certain aerosol particles, whether natural or synthetic, could cause clouds to brighten.
Brighter clouds would reflect more sunlight away from Earth, leading to localized cooling. If implemented on a large scale, solar geoengineering might offset the rapidly worsening impacts of climate change. The experiment was modest. The team sprayed sea salts for brief periods daily for four months from the deck of the USS Hornet, a decommissioned aircraft carrier docked in Alameda, California, to study particle dispersion.
However, public backlash was significant. Within two months of the experiment’s start, local officials voted unanimously to end it, citing the project’s lack of transparency, despite city consultants determining that the research wouldn’t impact wildlife or human health.
“This is the pitchfork brigades run amok,” Wake Smith, a climate researcher at Yale University, told environmental news agency Mongabay. “This involved spraying seawater into the air over the sea, mimicking the action of waves. It’s hard to conceive of a more harmless experiment. The Luddites are back.”
The public outcry in Alameda reflects several recent challenges faced by scientists attempting to research solar geoengineering through small-scale field experiments.
Meanwhile, a growing number of scientists are urgently calling for more research and funding into geoengineering. They’re not advocating for immediate deployment but emphasize that escalating emissions and worsening climate change impacts necessitate exploring all available options, even controversial ones.
However, not all scientists agree. Some criticized geoengineering as a dangerous distraction, arguing it shifts focus away from the crucial need for drastic emissions reductions and places humanity on a precarious path with potentially unforeseen consequences from untested technologies.
The debate extends beyond individual experiments to international forums. At the February 2024 United Nations Environment Assembly, Switzerland, supported by the U.S., Saudi Arabia, Canada, and Japan, clashed with African nations over advancing an expert panel to assess the benefits and risks of solar geoengineering. Switzerland did not prevail.
“I think the best way forward is to just take this option off the table, to stop these debates, and to support a non-use agreement on solar geoengineering,” said Frank Biermann, a social science researcher at the Global Sustainability Governance at Utrecht University in the Netherlands.
Paul Goddard does not agree. A researcher studying how solar geoengineering could slow melting in Antarctica, Goddard told Mongabay he couldn’t understand the opposition, as it “is potentially removing a great tool in the toolbox against climate change.”
Due to this heated dispute, those advocating for more field research to better understand solar geoengineering options are encountering roadblocks and issues of societal acceptance. At the same time, there is a growing shift as more researchers and policymakers begin to take solar geoengineering seriously.
Geoengineering research has become a political struggle, likely signaling even larger political battles over its deployment.
“It’s a political struggle of course, and there are people who have a lot of money; there’s a well-funded pro-SRM [solar radiation management] lobbying community in the United States and they’re doing their thing. They’re lobbying, they have money, we don’t have money,” Biermann said. “It’s a bit like David and Goliath.”
Reflecting on the David and Goliath story, it often seems that David is winning. In case after case, the opposition to geoengineering has halted field experiments. Biermann noted that one issue with geoengineering research is its frequent exclusion of social and governance considerations.
Those supporting geoengineering field research “are presumably natural scientists, so they have not been much involved in thinking about the political economy, the political ecology, and the governance challenges that come with [this new technology],” he explained.
Biermann doubts that any of the world’s current institutions could deploy geoengineering in a just manner.
“It will be hard to move forward until there are some full-throated advocates calling for it to countervail the full-throated opponents,” Smith said. “There is only so far that research can go without substantial public support.”
But Smith and others advocating for more field research argue that the dire impacts of climate change will eventually render this debate moot. It’s hard to imagine a non-use agreement preventing a nation from moving forward if millions of its citizens are displaced or perishing from extreme heat.
“Those disputing [solar geoengineering] do overplay risks, but more importantly, they underplay [the] risks of runaway climate change in the absence of solar [geoengineering],” Smith stressed. “They are implicitly comparing today’s climate to engineered climate, and saying, ‘I want today’s climate, not ‘Franken-climate!’ [man-made]. Well, so do I, but that won’t be the choice we will confront.”
References
Geoengineering Explained: Pros and Cons of Geoengineering
Don’t even study it: Geoengineering research hits societal roadblocks