Increase in precipitation contributes primarily to increase evapotranspiration rather than surface runoff, consistent with observations, and results in an additional cooling effect not fully accounted for in previous simulations with elevated CO2.
Thursday, December 9, 2010
New NASA Paper - It's Better Than We Thought!
More signs of cracks in the Warmist edifice when a NASA/NOAA paper is published saying that a doubling of CO2 would only cause a 1.6 Deg C rise in global temperatures due to increased vegetation growth having a negative feedback effect, absorbing CO2.
Bounoua and her colleagues write:
The NASA and NOAA boffins used their more accurate science to model a world where CO2levels have doubled to 780 parts per million (ppm) compared to today's 390-odd. They say that world would actually warm up by just 1.64°C overall, and the vegetation-cooling effect would be stronger over land to boot – thus temperatures on land would would be a further 0.3°C cooler compared to the present sims.
International diplomatic efforts under UN auspices are currently devoted to keeping global warming limited to 2°C or less, which under current climate models calls for holding CO2 to 450 ppm – or less in many analyses – a target widely regarded as unachievable. Doubled carbon levels are normally viewed in the current state of enviro play as a scenario that would lead to catastrophe; that is, to warming well beyond 2°C.
It now appears, however, that the previous/current state of climate science may simply have been wrong and that there's really no need to get in an immediate flap. If Bounoua and her colleagues are right, and CO2 levels keep on rising the way they have been lately (about 2 ppm each year), we can go a couple of centuries without any dangerous warming. There are lots of other factors in play, of course, but nonetheless the new analysis is very reassuring.
The fact that this paper has been published at all shows a sea change in attitude as it previously would never have seen the light of day.