Scientific American: Climate scientists may have to rethink some of their old assumptions about carbon. US and European researchers have just established that black carbon, soot and biochar -- the burnt remains from countless forest fires -- doesn't stay in the soil indefinitely.
Around 27 million tons of the stuff gets dissolved in water and washed down the rivers into the oceans each year.
Black carbon or biochar has been hailed as one possible way of limiting greenhouse gas emissions, by taking carbon out of...