Geographer Tim DeVries and colleagues determine why the ocean has absorbed more carbon over the past decade.
Geographer Tim DeVries and colleagues determine why the ocean has absorbed more carbon over the past decade.
With the ocean absorbing more carbon dioxide (CO2) over the past decade, less of the greenhouse gas is reaching the Earth’s atmosphere. That’s decidedly good news, but it comes with a catch: Rising levels of CO2 in the ocean promote acidification, which breaks down the calcium carbonate shells of some marine organisms.
The cause of this recent increase in oceanic CO2 uptake, which has implications for climate change, has been a mystery. But new research from UC Santa Barbara geographer Timothy DeVries and colleagues demonstrates that a slowdown of the ocean’s overturning circulation is the likely catalyst. Their findings appear in the journal Nature.
“Such a slowdown is consistent with the projected effects of anthropogenic climate change, where warming and freshening of the surface ocean from melting ice caps leads to weaker overturning circulation,” DeVries explained. “But over the time periods we studied, it’s not possible to say whether the slowdown is related to natural climate variability or to climate change caused by human activity.”
DeVries and fellow researchers Mark Holzer of the University of New South Wales in Sydney and François Primeau of UC Irvine compiled existing oceanographic tracer data — measurements of temperature, salinity, CFCs (manmade gases that dissolve into the ocean) and carbon-14 — and separated it into three decade-long time periods: the 1980s, the 1990s and the 2000s.
Read more at University of California - Santa Barbara
Photo credit: Kein via Wikimedia Commons
