One of the reasons that I'm suspicious of climate hysterics is that they seem to know so little about the carbon cycle and initial conditions. They don't seem to know the current state of things and don't seem to understand the dynamics of the system. They have a hugely simplified view of reality.

A detailed analysis of black carbon -- the residue of burned organic matter -- in computer climate models suggests that those models may be overestimating global warming predictions.

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.

As a result of global warming, soils are expected to release more carbon dioxide, the major greenhouse gas, into the atmosphere, which, in turn, creates more warming. Climate models try to incorporate these increases of carbon dioxide from soils as the planet warms, but results vary greatly when realistic estimates of black carbon in soils are included in the predictions, the study found.

Soils include many forms of carbon, including organic carbon from leaf litter and vegetation and black carbon from the burning of organic matter. It takes a few years for organic carbon to decompose, as microbes eat it and convert it to carbon dioxide. But black carbon can take 1,000-2,000 years, on average, to convert to carbon dioxide.

By entering realistic estimates of stocks of black carbon in soil from two Australian savannas into a computer model that calculates carbon dioxide release from soil, the researchers 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 findings are significant because soils are by far the world's largest source of carbon dioxide, producing 10 times more carbon dioxide each year than all the carbon dioxide emissions from human activities combined. Small changes in how carbon emissions from soils are estimated, therefore, can have a large impact.

Johannes Lehmann is the biochar guy so you can see where this is going. A better understanding of the various forms of soil carbon, and a better appreciation for its significance, can lead to more rational policies about both soil and climate. This implies changed energy and food policies.

Let's focus on that one Lehmann factoid: "soils are by far the world's largest source of carbon dioxide, producing 10 times more carbon dioxide each year than all the carbon dioxide emissions from human activities combined."

That can't be stopped since it is the natural and necessary decomposition of plant flesh that creates all that CO2. It's releasing CO2 drawn from the air by living plants back to where it came from. It feeds soil micro and microorganisms that are also necessary to planetary health. But the process can be slowed so that carbon builds up in soils, and since we have excess CO2 in the air it won't have a negative impact on plant breathing. This is good in countless ways, not least that increasing the size of the soil carbon working set reduces atmospheric concentrations. As Lehmann notes: "Small changes in how carbon emissions from soils are estimated, therefore, can have a large impact."