Nature Reports Climate Change
Published online: 20 November 2008 | doi:10.1038/climate.2008.122
Carbon is forever
Carbon dioxide emissions and their associated warming could linger for millennia, according to some climate scientists. Mason Inman looks at why the fallout from burning fossil fuels could last far longer than expected.
Carbon is forever
Distant future: our continued use of fossil fuels could leave a CO2legacy that lasts millennia, says climatologist David Archer
123RF.COM/PAUL MOORE
After our fossil fuel blow-out, how long will the CO2 hangover last? And what about the global fever that comes along with it? These sound like simple questions, but the answers are complex — and not well understood or appreciated outside a small group of climate scientists. Popular books on climate change — even those written by scientists — if they mention the lifetime of CO2 at all, typically say it lasts "a century or more"1 or "more than a hundred years".
"That's complete nonsense," says Ken Caldeira of the Carnegie Institution for Science in Stanford, California. It doesn't help that the summaries in the Intergovernmental Panel on Climate Change (IPCC) reports have confused the issue, allege Caldeira and colleagues in an upcoming paper in Annual Reviews of Earth and Planetary Sciences2. Now he and a few other climate scientists are trying to spread the word that human-generated CO2, and the warming it brings, will linger far into the future — unless we take heroic measures to pull the gas out of the air.
University of Chicago oceanographer David Archer, who led the study with Caldeira and others, is credited with doing more than anyone to show how long CO2 from fossil fuels will last in the atmosphere. As he puts it in his new book The Long Thaw, "The lifetime of fossil fuel CO2 in the atmosphere is a few centuries, plus 25 percent that lasts essentially forever. The next time you fill your tank, reflect upon this"3.
"The climatic impacts of releasing fossil fuel CO2 to the atmosphere will last longer than Stonehenge," Archer writes. "Longer than time capsules, longer than nuclear waste, far longer than the age of human civilization so far."