Dec 7, 2013
More Heatwaves by 2020 ‘Almost Certain’
Posted on Aug 16, 2013
By Tim Radford, Climate News Network
The researchers calculate that because of extreme events that already occur, terrestrial ecosystems – forests, marshes, mangrove swamps, grasslands and so on – absorb around 11 billion tons of carbon dioxide less than they would if there were no extremes.
This time, they weren’t working just with simulations. They pored over satellite images from 1982 to 2011 to work out how much biomass a particular ecosystem accumulated during or after an extreme weather event.
They also used data from a global network of recording stations that samples the air above forest canopies to check their figures, and came to the total of 11 billion tons. “That is roughly equivalent to the amount of carbon dioxide sequestered in terrestrial environments every year”, said Dr Reichstein. “It is therefore by no means negligible.”
The next step is to investigate the ways that ecosystems respond to events. Experiments so far have measured responses only to so-called “once a century” events.
“We should also take account of events which so far have happened once in 1,000 years or even 10,000 years”, said Michael Bahn from the University of Innsbruck, “because they are likely to become much more frequent by the end of this century.”
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