Scientist says ancient technique cuts greenhouse gas

By Gerard Wynn Science News
POZNAN, Poland (Reuters) - An ancient technique of plowing charred plants into the ground to revive soil may also trap greenhouse gases for thousands of years and forestall global warming, scientists said on Friday.
Heating plants such as farm waste or wood in airtight conditions produces a high-carbon substance called biochar, which can store the greenhouse gas carbon dioxide and enhance nutrients in the soil.
Plants absorb carbon dioxide from the atmosphere as they grow. Subsequently storing that carbon in the soil removes the gas from the atmosphere.
"I feel confident that the (carbon storage) time of stable biochar is from high hundreds to a few thousand years," said Cornell University's Johannes Lehmann, at an event on the sidelines of U.N. climate talks in the Polish city of Poznan.
Lehmann estimated that under ambitious scenarios biochar could store 1 billion tons of carbon annually -- equivalent to more than 10 percent of global carbon emissions, which amounted to 8.5 billion tons in 2007.
Under a conservative scenario the technique could store 0.2 billion tons of carbon annually, he said. That would still require heating without oxygen -- called pyrolysis -- some 27 percent of global crop waste and plowing this into the soil.
Lehmann cited experiments on 10 farm crops suggesting biochar can also increase yields by up to three times, because the organic matter holds on to nutrients. Read whole story. Looks like we will save the earth after all now that the Bush Administration is almost over.