Rate of atmospheric carbon dioxide rise unprecedented
Human activity dwarfs fastest increase since time of dinosaurs, study finds
CLIMBING CARBON The rate of extra carbon currently entering the atmosphere is unmatched in at least 66 million years. Not even a massive outpouring of carbon 56 million years ago (recorded in this ocean sediment core as the 25-centimeter-long red band) comes close, a new study suggests.
James Zachos
MONTREAL — Humans are dumping extra carbon into the atmosphere at a rate unprecedented since at least the time the dinosaurs went extinct about 66 million years ago, new research suggests.
Previously, a massive outpouring of carbon about 56 million years ago had been proposed as faster than the current rate of net increase in atmospheric carbon. But researchers comparing data collected from ocean sediment cores with climate simulations show that this event at most reached only about a tenth of today’s carbon increase rate. The work suggests that no direct historical analogs exist to help predict the planet’s response to rapidly amassing greenhouse gases, the researchers said May 6 at a meeting of the American Geophysical Union and other organizations.
