Carbon dioxide levels in the atmosphere are at a 15 million year high, according to researchers at the University of California at Los Angeles.
“The only time in the last 20 million years that we find evidence for carbon dioxide levels similar to the modern level of 387 parts per million was 15 to 20 million years ago, when the planet was dramatically different,” said lead researcher Aradhna Tripati, a UCLA assistant professor in the department of Earth and Space Sciences. She called it “a slightly shocking finding.”
The report was released yesterday and appeared in the online edition of the journal Science.
Researchers have been able to gauge CO2 levels over the past 800,000 years by analyzing ice core samples, which trap gas inside bubbles. But they were unable to go back further than that.
In this project, scientists studied the chemical makeup of ancient single cell marine algae. They found that results matched the readings in ice core samples – but they were then able to reach conclusions about the atmosphere as far back as 20 million years.
They estimated that CO2 levels were about 400 parts per million during the period from 14 to 20 million years ago.
“The last time carbon dioxide levels were apparently as high as they are today – and were sustained at those levels – global temperatures were 5 to 10 degrees Fahrenheit higher than they are today,” Tripati said. “The sea level was approximately 75 to 120 feet higher than today, there was no permanent sea ice cap in the Arctic and very little ice on Antarctica and Greenland.”
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EVEN THE STREET GANGS ARE GETTING HOT: Graffiti I spotted on a building in downtown West Palm Beach yesterday – “Endless summer.”
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TROPICAL UPDATE: Tropical Storm Henri dissipated to a remnant low last night. The system was still producing sporadic blowups of convection as it moved west toward Puerto Rico. The National Hurricane Center said it did not expect Henri to regenerate.
The second system being watched by forecasters, tagged Invest 92L by the NHC, was moving west into the Caribbean today. It was hugging the coast of South America and was given a low chance of developing into a tropical storm due to its proximity to land.
Photo: http://www.flickr.com/photos/eye2eye/132813936/
