University of Reading researchers have denounced the controversial idea of 'Geo-engineering' to offset the effects of global warming. They claimed that the intentional attempt to change the Earth's climate could backfire and lead to droughts and climate chaos in the poorest parts of the world.

Geo-engineering involves the process of artificial spraying of minute reflective particles into the upper atmosphere to prevent solar energy from reaching the surface. The idea is being seriously considered as an alternative if global efforts to cut down greenhouse gases fail.

Using computer models of the plan, the researchers said that constant injection of sulphates in large quantities into the stratosphere could cause altered rainfall patterns around the equator. It could dry out the tropical rainforests in South America and Asia and give rise to serious droughts in Africa.

While countries in Northern Europe and parts of Asia would probably benefit from the process, it would do more harm than good.

The Geo-engineering process mimics the cooling effects of huge volcanic eruptions. It is a known fact that the sulphate particles generated by volcanoes reduce incoming solar radiation significantly and cool global temperatures.

"We have shown that one of the leading candidates for geo-engineering could cause a new unintended side-effect over a large part of the planet," Andrew Charlton-Perez, a co-author of the study, said in a statement. "The risks from this kind of geo-engineering are huge."

Charlton-Perez said that Indonesia, for example, could rapidly become arid if the tropical rainfall reduces by 30 percent.

"The ecosystems of the tropics are among the most fragile on Earth. We would see changes happening so quickly that there would be little time for people to adapt. Discussion of geo-engineering often prompts heated debate, but very often there is a lack of understanding of what putting large amounts of aerosol in the stratosphere will do to the complex climate system.

In order to significantly reduce the predicted 4C rise in global temperatures, sulphate aerosols need to be injected in huge amounts into the upper atmosphere for several years continuously.

"To reduce global temperatures enough to counter effects of global warming would require a massive injection of aerosol - the small particles that reflect sunlight back into space. This would be equivalent to a volcanic eruption five times the size of that of Mount Pinatubo every year," Angus Ferraro of Exeter University said.

The finding has been published in the journal Environmental Research Letters.

Topics Reading, Planet, Global warming, Earth, Climate