Updated Feb 28, 2023, 11:42am EST
net zerotech

The UN wants to explore a last-ditch climate solution that could start wars

A photo shows the sun appearing to set into the sea off the Italian coast.
Wikimedia Commons/Vincenzo Gianferrari Pini

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The News

With global warming expected to surpass the 1.5 Celsius threshold within the next 15 years, the United Nations Environment Programme (UNEP) is calling for research into a different and more controversial approach: solar geoengineering.

A new report released by the UNEP Monday argues that while geoengineering, also known as solar radiation modification (SRM), is a quick way to cool the planet, it is not without its own risks.

The scientists behind the report are suggesting more investigation into the benefits — and possibly extreme consequences — of SRM.

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The Facts

What is SRM?

Solar radiation modification is a process that would reflect “some amount of incoming solar energy back into space before that energy can be trapped by the gases that produce the greenhouse effect,” according to American University professor Simon Nicholson. It acts as a “reflective shield” essentially blocking sunlight to cool the earth more rapidly.


Does that mean we could stop trying to hit net zero?

No. SRM would cool the earth, but it wouldn’t eliminate the effects of climate change. Issues such as ocean acidification, sea level rise, and extreme weather events would persist unless addressed directly, the UN report says.

What are the risks?

There are many varied risks with SRM, from damage to the ozone layer to rapid global warming if the program ends too quickly. The report notes that solar geoengineering could potentially spark conflicts between countries or be misused by rogue states or private entities.

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Know More

With such major risks to deploying SRM, including the threat of global conflict, the UNEP suggests that more research is required to analyze the cost and benefit of solar geoengineering.


While global warming is rapidly moving towards 1.5 Celsius, the report’s authors don’t think the time is right to implement the measure, and describe such a move in the near- to mid-term as “unwise.”

The review concluded that SRM “cannot replace reducing greenhouse gas emissions.”

SRM would be “at best a temporary measure,” the report’s authors said, which would have to operate simultaneously to other climate change mitigation strategies.

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The View From Mexico

SRM is so controversial that some countries are already prohibiting experiments which would test its effectiveness.

In Mexico, solar geoengineering trials were banned last month after a startup in Baja California launched sulfur dioxide into the stratosphere, using supplies like weather balloons which it purchased off Amazon.

The startup didn’t track its balloons, so it’s unclear if the experiment yielded any early results.

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  • The U.S. intelligence community is already investigating how to prevent a war which could start if solar geoengineering leads to tensions between countries, The Washington Post reports. Janos Pasztor, a former UN official, described the possible conflicts as “a powder keg.”
  • Billionaires kind of love the idea of blocking out the sun, Time magazine reports. George Soros is the latest to throw himself behind research into SRM, but Bill Gates, Jeff Bezos, and Dustin Moskovitz have all invested money into researching the method, too.