Human-spewed CO2 overwhelming Earth’s defenses
April 28th, 2008 by Jim JustThe earth’s carbon cycle has natural negative feedbacks that reverse natural surges in carbon dioxide. But we are spewing CO2 into the atmosphere 14,000 times faster than nature has over the past 600,000 years – far too quickly for natural feedbacks to respond.
A study by Richard Zeebe and Ken Caldeira titled “Close mass balance of long-term carbon fluxes from ice-core CO2 and ocean chemistry records” in Nature Geosciences (subs. reqd.). A Reuters article includes this quote from Zeebe:
“These feedbacks operate so slowly that they will not help us in terms of climate change . . . that we’re going to see in the next several hundred years. Right now we have put the system entirely out of equilibrium.”
And we’re putting more CO2 into the atmosphere than ever. The U.S. government reported last week that in 2007 alone, atmospheric carbon dioxide increased by 2.4 parts per million – an increase of 19 billion tons, or 0.6%.
The natural mechanism will eventually absorb the excess carbon dioxide – but not for hundreds of thousands of years.