Geoengineering is the large scale, deliberate manipulation of the earth's climate being researched as a possible way to counteract the effects of global warming.
There are many types of geoengineering, ranging from the relatively harmless – the planting of trees – to the more extreme, such as the spraying of sulphur in the stratosphere to act as a kind of giant mirror.
To date, no large scale geoengineering projects have been undertaken. Big projects will affect large areas of the planet and so have huge potential for political unrest. One country has the potential to affect the world.
There is a great deal of research going on however in order to access its potential and proposals for tests are being made. Environmentalists and geoengineering experts largely agree that it should not be used as an excuse not to reduce carbon emissions. It is largely viewed as a last resort, in case we are not able to reduce our carbon emissions in time.
An overview of geoengineering can be found on Wired.com(opens in a new window)
One of the world's leading experts on geoengineering is Ken Caldiera. You can read his research on the Carnegie Institution for Science website(opens in a new window)
'When Mount Pinatubo erupted in the Philippines on 15 June 1991, an estimated 20 million tons of sulphur dioxide and ash particles blasted more than 12 miles (20km) high into the atmosphere.'
– Jason Wolfe; Volcanoes and Climate Change (opens in a new window), NASA Earth Observatory, 5 Sept 2000.
'Friends of the Earth, and leading scientists studying geoengineering options, believes that making rapid carbon reductions is the priority but that geoengineering may have some necessary role in supplementing this action.'
– Friends of the Earth; Briefing note: Geoengineering (opens in a new window), Nov 2009.
'Tinkering with our entire planetary system is not a silver bullet. It's an expression of political despair'
– Doug Parr, Greenpeace UK's chief scientist, Geoengineering is no solution to climate change(opens in a new window), Sept 2008.
'Proposed methods of delivering the sulphur to the stratosphere include airplanes, cannons and balloon suspended hoses. One or two million tons of sulphur a year could keep the earth's temperature level even if greenhouse emissions doubled.'
Stewart Brand(opens in a new window), ; Whole Earth Discipline, p284.
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