Recent observations show that societies are highly vulnerable to even modest levels of climate change, with poor nations and communities particularly at risk. Temperature rises above 2°C will be very difficult for contemporary societies to cope with, and will increase the level of climate disruption through the rest of the century.

Scientists must make clear the disastrous effects of climate change so the world takes action now to cut carbon emissions, leading economist Nicholas Stern said on told the gathering of 2,000 scientists.