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Intelligence Squared debate: Engineering solar radiation is a crazy idea

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Sunrise on a lake with a dock and boat.
Johannes Plenio | Unsplash file

Geoengineering is an ambitious set of experiments proposed by scientists to help mitigate the effects of climate change. And one type in particular — called solar geoengineering — has been the subject of debate.

This process involves, among other techniques, injecting reflective particles into the stratosphere to reduce the amount of sun and heat that reaches the planet.

The goal? To decrease global temperatures. Proponents argue this process would be inexpensive and effective. Plus, they say, it could limit changes in glacier melt and lessen the intensity of tropical storms.

But challengers argue these techniques do not address the underlying issues of climate change, and they worry that solar geoengineering could alter weather systems or possibly even cool the planet too much.

They also point to governance issues: Any country could engage these strategies, triggering the possibility of unintended consequences that could affect us all. Is solar geoengineering a radical idea? Or is it likely to emerge as an important, supplemental tool in the fight against climate change?

The Intelligence Squared debate motion: Engineering solar radiation is a crazy idea.

For the motion:  

• Clive Hamilton, author of "Earthmasters: The Dawn of the Age of Climate Engineering."

"Each decision will change the weather conditions of some people more than others. Who would you trust to have such power? Our opponents believe that it will be done on the advice of a cohort of clever, rational scientists. But that's not how the world works." 

• Anjali Viswamohanan, scholar at University of Oxford.

"The list of negative impacts on deployment is quite long, but one of the most immediate impacts will be to the change in the precipitation cycles. It will also affect tropical forests, the ozone layer, and the oceans." 

Against the motion:

• David Keith, professor at Harvard and founder of Carbon Engineering.

"Our contention is that solar geoengineering might be part of the way that humans manage environmental risks of climate change this century, that a combination of emissions cuts, adaptation, carbon removal, and solar geoengineering might enable a safer climate." 

• Ted Parson, professor at University of California, Los Angeles.

"Removing CO2 from the atmosphere is like draining a lake through a straw. It will work, but it'll take a long time. Deep emission cuts and carbon removal are both essential, but they may not be enough soon enough, even with extreme efforts. We need something else, and geoengineering might be that something else."