Injecting sulfate particles into stratosphere won’t fully offset climate change

Vince Stricherz in the University of Washington Today: As the reality and the impact of climate warming have become clearer in the last decade, researchers have looked for possible engineering solutions – such as removing carbon dioxide from the atmosphere or directing the sun’s heat away from Earth – to help offset rising temperatures.

New University of Washington research demonstrates that one suggested method, injecting sulfate particles into the stratosphere, would likely achieve only part of the desired effect, and could carry serious, if unintended, consequences.

The lower atmosphere already contains tiny sulfate and sea salt particles, called aerosols, that reflect energy from the sun into space. Some have suggested injecting sulfate particles directly into the stratosphere to enhance the effect, and also to reduce the rate of future warming that would result from continued increases in atmospheric carbon dioxide.

But a UW modeling study shows that sulfate particles in the stratosphere will not necessarily offset all the effects of future increases in atmospheric carbon dioxide. Additionally, there still is likely to be significant warming in regions where climate change impacts originally prompted a desire for geoengineered solutions, said Kelly McCusker, a UW doctoral student in atmospheric sciences.

The modeling study shows that significant changes would still occur because even increased aerosol levels cannot balance changes in atmospheric and oceanic circulation brought on by higher levels of atmospheric carbon dioxide. “There is no way to keep the climate the way it is now. Later this century, you would not be able to recreate present-day Earth just by adding sulfate aerosols to the atmosphere,” McCusker said...

An aerosol spray can, shot by PiccoloNamek, Wikimedia Commons, under the Creative Commons Attribution ShareAlike 3.0 License