Natural sinks still sopping up carbon
Earth's ecosystems keep soaking up more carbon as greenhouse gases accumulate in the atmosphere, new measurements find.
The research contradicts several recent studies suggesting that "carbon sinks" have reached or passed their capacity. By looking at global measurements of atmospheric carbon dioxide, the new work calculates instead that total sinks have increased roughly in line with rising emissions.
"The sinks have been more than able to keep up with emissions," said Pieter Tans, an atmospheric scientist at the National Oceanic and Atmospheric Administration's Earth System Research Laboratory in Boulder, Colo. Tans presented the findings May 15 at an annual conference on global monitoring hosted by the lab.
Careful measurements of atmospheric carbon dioxide taken in the rarefied air atop Mauna Loa, Hawaii, and elsewhere have established that levels of the gas are rising steadily, from 316 parts per million in 1959 to 392 parts per million today. The question is how Earth's great ecosystems respond to that increase. Forests can suck down carbon dioxide through photosynthesis, whereas oceans take it up proportionally as levels rise in the air.
Previous work has relied on carbon inventories that gather data from multiple sources to try to estimate how much is being put into the atmosphere and how much is being taken out every year. For the new study, Tans and his colleagues went back to basics, choosing 42 marine sites where carbon dioxide levels have been measured for decades.
Article continues Science News
Planet Earth image via Shutterstock