Washington: Cheer up -- the earth may yet be able to recover faster from rising carbon dioxide (CO2) emissions than previously thought.
When faced with high levels of atmospheric CO2 and rising temperatures 56 million years ago, our planet increased its ability to pull carbon from the air.
This led to a recovery that was quicker than anticipated by many models of the carbon cycle, though still on the order of tens of thousands of years, said Gabriel Bowen, associate professor of atmospheric sciences at Purdue University, who led the study.
"We found that more than half of the added carbon dioxide was pulled from the atmosphere within 30,000 to 40,000 years, which is one-third of the time span previously thought," said Bowen, the journal Nature Geoscience reports.
"We still don`t know exactly where this carbon went, but the evidence suggests it was a much more dynamic response than traditional models represent," a Purdue statement quoted him as saying.
Bowen worked with James Zachos, professor of earth and planetary sciences at the
University of California, Santa Cruz, to study the end of the Palaeocene-Eocene Thermal
Maximum, a 170,000-year-period of global warming having many paralles with the world`s current situation, he said.
"During this prehistoric event, billions of tonnes of carbon were released into the ocean, atmosphere and biosphere, causing warming of about five degrees Celsius," Bowen said.
"This is a good analog for the carbon being released from fossil fuels today," Bowen said.
Scientists have known of this prehistoric event for 20 years, but how the system recovered and returned to normal atmospheric levels has remained a mystery.