Microbes and Global Warming
For years, climate scientists have puzzled about the impact of warming on the silent living things - microbes - under foot and out of sight. They identified the microbial world as the key to the puzzle of the carbon budget and wondered about the rate at which soil could absorb carbon and store it. They also warned that, in a warmer world, soil microbes might become more active.
Microbes are putting more energy into the the important business of decay and recycling, carbon dioxide is being exhaled back into the atmosphere at a faster rate.About 25 years ago, microbes accounted for 54% of soil respiration. Now they account for 63%.
And their numbers are huge: so vast that the terrestrial bacteria add up to 70 billion tons of living carbon, and fungi another 12 billion tons, according to a recent estimate. Together these microbes weigh 40 times as much as all the animals on the planet.
As a consequence, more carbon dioxide escapes into the atmosphere, according to a new study. And since there is twice as much carbon in the soil - mostly in the form of plant detritus as there is in the atmosphere, the discovery is ominous.