The World At 4C By 2060
By John James
27 October, 2009
Countercurrents.org
London Science Museum unveils climate change map showing impact of 4C rise.
http://guardian.co.uk:80/environment/2009/oct/
22/science-museum-climate-map
A new interactive map of the world that details the likely effects of a failure to cut carbons emissions has been developed by Met Office scientists David Adam and Allegra Stratton, showing the impact of a global temperature rise of 4C that John Beddington, the government's chief scientist, said would be "disastrous".
A study by the Met Office last month said that such a 4C rise could come as soon as 2060 without urgent and serious action to reduce emissions.
David Miliband, foreign secretary, said a new deal needed to be strong enough to limit global temperature rise to 2C, although many involved in the negotiations privately believe this to be impossible. The map's release marks a significant shift in political discourse on climate change, with many politicians until recently unwilling to discuss the possibility of a failure to hit the 2C target.
David Miliband warned today that the Copenhagen talks were "the most complicated international negotiations ever attempted". He predicted that unless climate change was slowed there would be "high pressure" on water and food shortages. "We cannot cope with a 4C world. This map clearly illustrates the scale of the challenge facing us today ... To tackle the problem of climate change, all of us, foreign ministries, environment ministries, treasuries, departments of defence, and all parts of government and societies, must work together to keep global temperatures to 2C. Britain's scientists have helped to illustrate the catastrophic effects that will result if the world fails to limit the global temperature rise to 2C.
The map is based on temperatures between 2060 and 2100 if current rates of climate change are not slowed. It shows that the rise will not evenly be spread across the globe, with temperature rises much larger than 4C in high latitudes such as the Arctic. Because the sea warms more slowly, average land temperature will increase by 5.5C, which scientists said would shrink agricultural yields for all major cereal crops on all major regions of production. A 4C world would also have a major impact on water availability, and bad news for the Amazon, with some computer models predicting severe drying and subsequent die-back.
One of the biggest, more subtle, effects could be on the way the world's oceans and ecosystems absorb carbon. About half of our carbon emissions are currently soaked up in this way, which helps put the brake on global warming. In a 4C world, scientists say the amount of emissions re-absorbed in this way could shrink to just 30%.
