Artificially cooling planet would cause climate chaos, scientists say

A press release from the University of Reading: Plans to reverse the effects of global warming by mimicking big volcanic eruptions would have a catastrophic impact on some of the most fragile ecosystems on earth, according to new research from the University of Reading.

Geo-engineering - the intentional manipulation of the climate to counter the effect of global warming - is being proposed as a last-ditch way to deal with the problems of climate change. However, University of Reading research suggests geo-engineering could cause massive changes to rainfall patterns around the equator, drying the tropical rainforests in South America and Asia and intensifying periods of drought in Africa.

• Pumping sunlight-reflecting particles into the atmosphere would cut tropical rainfall by 30%
• Reversing a 4 deg C temperature rise could benefit northern Europe but lead to drought in parts of South America, Asia and Africa

The research also highlights how global geo-engineering could provide solutions for some regions while causing more problems in others, opening up the possibility of conflict between countries if they were to act unilaterally to alter the climate. In general, countries in northern Europe and parts of Asia would be most likely to benefit, at the expense of parts of Africa, North and South America and South-East Asia.

Geo-engineering is a hot topic. Governments and the world's leading climate scientists on the UN's Intergovernmental Panel on Climate Change (IPCC) discussed the prospect of artificially cooling the climate at its meeting in Stockholm in September 2013.

Aerosols in the stratosphere reflect sunlight, reducing the amount of solar energy reaching the surface. This occurs naturally after big volcanic eruptions, such as that of Mount Pinatubo in 1991, which led to a large short-term dip in global temperatures. Aerosols could potentially be artificially sprayed into the upper atmosphere to counteract the effects of climate change.

But the researchers suggest that such stratospheric aerosol injection, probably the leading candidate for a workable geo-engineering scheme, would create significant, harmful side effects by weakening weather systems in the tropics....

Map from the University of Reading website