Global warming will expand forests over what are now grasslands.

According to a new study, "savanna trees were essentially CO2-starved under pre-industrial CO2 concentrations, and that their growth really starts taking off at the CO2 concentrations we are currently experiencing.“

These burgeoning forests will then rather neatly lock up in the biosphere all that extra carbon that we have been releasing into the atmosphere. Or some of it. But the major point of this paper is that far from climate change being a threat to the tropical forests, it looks as if it will be the cause of more of them growing....

Now all we have to hope for is that the upcoming IPCC report, the fifth, will report honestly and openly upon all the effects of rising CO2 levels so we can work out whether it's worth ditching industrial civilisation or not.... We know very well what the direct effect of a doubling of atmospheric CO2 is: a 0.7 degree rise in temperature – that's just straight physics. The idea that we might get 2 or 4 or 5 degrees of temperature change comes from the interaction of positive and negative feedback mechanisms. And we don't know what all of those mechanisms are, don't know the direction of some of them and are really very unsure indeed what the total value is.