Here's the countdown to climate armageddon.
It has take 250 years to burn the first half trillion tons of carbon and current trends suggest it will take less that 40 years to burn the next half trillion. That's 2050.
To avoid dangerous climate change of 2C, the world can only burn another half a trillion tonnes of carbon, climate change experts warn.
The world has already burned half the fossil fuels necessary to bring about a catastrophic 2C rise in average global temperature, scientists revealed today.
The experts say about half a trillion tonnes of carbon have been consumed since the industrial revolution. To prevent a 2C rise, they say, the total burnt must be kept to below a trillion tonnes. On current rates, that figure will be reached in 40 years.
Writing in today's Nature, Allen and colleagues say a trillion tonnes of carbon burnt would be likely to produce a warming of between 1.6C and 2.6C, with a "most likely" 2C rise.
http://www.guardian.co.uk/environment/2009/apr/29/fossil-fuels-trillion-tonnes-burned