The geoengineering debate: Can imitating volcanic eruptions combat climate change?

Over recent years, the once controversial idea of combatting climate change through geoenginnering has slowly been gaining popularity, with some scientists suggesting it could be an important tactic in fixing our global warming problems. New research from the University of Exeter is now offering evidence that this untested approach could in fact cause climate chaos, resulting in both more drought and tropical cyclones around the globe.

One of the key geoengineering strategies floated by scientists is inspired by the effects of volcanic eruptions. When a volcano erupts it launches particles into the stratosphere that reflect sunlight and temporarily cool the planet before falling back to Earth.

Unsurprisingly, this idea is controversial, but it is being quite seriously explored by many scientists and policymakers. A recent Harvard study, for example, has identified a particle that could be the safest and most effective candidate for launching into the atmosphere.

While some studies suggest the technique would be effective in reducing the global temperature, and even potentially improving crop yields, the global climate effects remain unknown – and, according to Naomi Klein, ultimately untestable.

"…you could not conduct meaningful tests of these technologies without enlisting billions of people as guinea pigs – for years. Which is why science historian James Fleming calls geoengineering schemes 'untested and untestable, and dangerous beyond belief',"writes Klein.

A new study from the University of Exeter uses complex climate modeling to simulate the global effects of the most popular form of localized atmospheric geoengineering called stratospheric aerosol injection (SAI).

The results were significant and broad, with aerosol injection into the atmosphere in the Northern Hemisphere reducing tropical cyclone frequency in the North Atlantic and causing drought in the Africal Sahel region, while aerosol injection in the Southern Hemisphere would cause the opposite effect, increasing tropical cyclone frequency in the North Atlantic.

"Our results confirm that regional solar geoengineering is a highly risky strategy which could simultaneously benefit one region to the detriment of another," says lead author on the paper, Anthony Jones.

Some scientists are already calling for small-scale experiments in these geoengineering techniques, but Jones and his research team see this as shortsighted and drastically misunderstanding the risk of affecting weather systems outside of the local climate that is being specifically targeted.

"It is vital that policymakers take solar geoengineering seriously and act swiftly to install effective regulation," says Jones.

It's a minefield of a research area with opinions oscillating from continuing the research cautiously as a long-term emergency back-up plan to Naomi Klein's assertion that geoengineering research is dangerous and will result in "life-changing consequences".

The new study was published in the journal Nature Communications.

Source: University of Exeter