Less freshwater availability, and with it more intense droughts, is likely to occur in West Africa, Central America, southern Europe and the eastern USA. Other regions will be at significant risk of excessive runoff as trees are lost, increasing the chances of flooding as temperatures rise.
The researchers also found that if the temperature increase is more than 3°C, land carbon sinks could release their stored carbon, starting a positive feedback loop that would increase atmospheric carbon dioxide.
QUEST (Quantifying and Understanding the Earth System) is a £21 million programme funded by the Natural Environment Research Council (NERC).