Global Warning Predictions Overestimated?

November 25th, 2008

Mandatory preface to these kinds of posts requires that I say in advance this post has nothing to do with saying that global warming does not exist. The last thing I need is a bunch of greenies hopped up on Ephedrasil hardcore acting like someone just killed their family because they think that some idiot is saying there is no global warming. So…read what this is about before you get your panties in a bunch.

A detailed analysis of black carbon, which is the residue of burned organic matter in computer climate models suggests that those models may be overestimating global warming predictions. By entering realistic estimates of black carbon in soil from two Australian savannas into a computer model that calculates carbon dioxide release from soil, researchers have found that carbon dioxide emissions from soils were reduced by about 20 percent over 100 years, as compared with simulations that did not take black carbon’s long shelf life into account.

The Earth’s soil is responsible for releasing 10 times the amount of carbon dioxide than all man made activities combined. So if the measurements made from soils has been wrong then there could be a major impact in the overall outlook. A small change in the soil measurements would have a great influence.

A new Cornell study, published online in Nature Geosciences, quantified the amount of black carbon in Australian soils and found that there was far more than expected, said Johannes Lehmann, the paper’s lead author and a Cornell professor of biogeochemistry. The survey was the largest of black carbon ever published.

“We know from measurements that climate change today is worse than people have predicted,” said Lehmann. “But this particular aspect, black carbon’s stability in soil, if incorporated in climate models, would actually decrease climate predictions.”

The study quantified the amount of black carbon in 452 Australian soils across two savannas. Black carbon content varied widely, between zero and more than 80 percent, in soils across Australia.

“It’s a mistake to look at soil as one blob of carbon,” said Lehmann. “Rather, it has different chemical components with different characteristics. In this way, soil will interact differently to warming based on what’s in it.”