Guest essay by Eric Worrall

The show must go on; According to academics, Climate Geoengineers would have to stand ready to recalibrate their efforts if a major volcanic eruption or nuclear exchange affects stratospheric dust levels, or if a repeat of the Carrington Event damages their machines.

Trying to cool the Earth by dimming sunlight could be worse than global warming

February 7, 2022 11.46pm AEDT

Luke Kemp
Postdoctoral Research Associate in Existential Risk, University of Cambridge

Aaron Tang
PhD Scholar in Climate Governance, Australian National University

A group of 60 scientists called for a moratorium on solar geoengineering last month, including technologies such as stratospheric aerosol injection (SAI). This involves a fleet of aeroplanes releasing aerosol particles – which reflect sunlight back to outer space – into the atmosphere, cooling down the Earth. 

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A cooler Earth means less water would be evaporating from its surfaces into the atmosphere, changing rainfall patterns. This could produce ripple effects across the world’s ecosystems – but the exact nature of these effects depends on how SAI is used. Poor coordination of aerosol release could lead to extreme rainfall in some places and blistering drought in others, further triggering the spread of diseases.

SAI could also make natural catastrophes worse than they currently are. A volcanic eruption, like that of Iceland’s Eyjafjallajökull volcano in 2010, could naturally cool the Earth as plumes of ash block sunlight from reaching the planet’s surface. If this happened while SAI was deployed, it would have to be urgently adjusted (not an easy feat) to avoid overcooling one hemisphere and producing extreme weather patterns as a result.

Similarly, although nuclear war may seem unlikely, global nuclear capabilities continue to grow, and bad political decision-makers are in no short supply. A “nuclear winter”, during which global temperatures drop for years due to soot clouds from nuclear-triggered fires, could be deepened by SAI.

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Read more: https://theconversation.com/trying-to-cool-the-earth-by-dimming-sunlight-could-be-worse-than-global-warming-175455

I kind of think of geoengineering as gain of function research on the global climate; zero public value, marginally useful in research terms, potentially catastrophic in impact.

I’m pretty sure in the event of a large regional or global catastrophe, people might have other priorities than maintaining funding for a pointless virtue signalling exercise. But its nice to see that scientists are starting to notice some downsides of their plans.