The hot controversy surrounding solar geoengineering

Could blocking the sun help reverse climate change? Scientists say maybe, thanks to solar geoengineering. The emerging solution is designed to cool the Earth and prevent catastrophic warming. Despite solar geoengineering's potential, some experts are wary of the solution's long-term effects on the planet's climate and weather patterns. Because of this, there has been a lack of experimentation or governance related to solar geoengineering. But with the atmospheric conditions rapidly worsening, cutting emissions alone may not be enough to curtail disaster. 

Sunblock, but bigger

As the planet's temperatures continue rising, scientists are exploring options to cool down the planet. One of those methods is geoengineering, an "umbrella term for any actions that try to change the climate of Earth itself artificially," said Popular Mechanics. While geoengineering can take many forms, solar geoengineering has recently garnered attention because of its controversial nature. Solar geoengineering "seeks to change the climate by blocking the sun with reflective materials. If solar radiation bounces off, proponents argue, then the Earth's climate will cool."

A number of solar geoengineering projects have been considered over the last 50 years, however, many governments and scientists are hesitant to permit actual experimentation. For example, a high-profile project at Harvard University was discontinued in March, with the project's platform being "repurposed for basic scientific research in the stratosphere unrelated to solar geoengineering," said an announcement from the university. Those in support of solar geoengineering, though, believe "scientists should explore all possible avenues to address the planet's rapidly rising temperatures," said Scientific American.

Subscribe to The Week

Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

SUBSCRIBE & SAVE

Sign up for The Week's Free Newsletters

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.

Sign up

Solar geoengineering has a lot of potential to help reverse global warming, but nobody is certain how manually cooling the Earth will affect other natural processes and organisms. "The thing is, these science-based guesses are still subject to the unexpected consequences that use in the real world might cause — and that's something we can't know unless scientists, somewhere, are allowed to do experiments of some kind," said Popular Mechanics. But there is no standard way to govern solar geoengineering, yet. "With many unknowns and risks, there is a strong need to establish an international scientific review process to identify scenarios, consequences, uncertainties and knowledge gaps," said a report by the United Nations Environment Programme.

Cloudy outcomes

The hesitancy around solar geoengineering stems from the field's myriad unknowns, as well as the potential lack of accountability. "Scientists caution that solar geoengineering could carry a wide array of unintended side effects, including negative impacts on the Earth's ozone layer or weather patterns," Scientific American said. Without opportunities to test the technology, those effects will remain a mystery. "For now, no one really knows what might happen with large-scale geoengineering projects. It might help cool down the planet; it also might rip open the ozone over Antarctica," said The Verge.

On top of potential environmental impacts, some fear solar geoengineering will remove the incentive for companies and countries to restrict greenhouse gas emissions. "Humanity must not pursue dangerous distractions that do nothing to tackle the root causes of climate change, come with incalculable risk and will likely further delay climate action," a group of scientists said in a piece for The Conversation. "Calls for outdoor experimentation of the technologies are misguided and detract energy and resources from what we need to do today: phase out fossil fuels and accelerate a just transition worldwide."

While cutting back on fossil fuels and curbing emissions are indeed necessary to combat climate change, they may not be enough. Lynn Russell, a climate scientist at the Scripps Institution of Oceanography at the University of California San Diego, said in a press release, "The recent acceleration of impacts from global warming means that we need to consider non-ideal backup plans just to buy us enough time to reduce greenhouse gas emissions and existing burdens."