CO2 levels reach milestone
The amount of CO2 in the atmosphere hasn’t been this high in at least 15 million years, according to study.
Fri, Oct 09, 2009 at 09:23 PM
SLIGHTLY SHOCKING: The Industrial Revolution helped create carbon dioxide levels that haven't been seen for at least 15 million years. (Photo: Jupiterimages)
The Earth’s atmosphere has achieved a feat not seen in at least 15 million years, according to UCLA assistant professor and lead author Aradhna Tripati, who recently found that today’s carbon dioxide (CO2) levels are so high that it’s necessary to go back millions of years just to find similar levels.
Until now, scientists could determine the Earth’s atmosphere only up to 800,000 years ago by looking at air bubbles trapped in Antarctic ice.
Tripati, however, wanted to go further, so while part of a research team at England’s University of Cambridge she helped develop a new technique that could determine the carbon dioxide levels of millions of years ago by “studying the ratio of the chemical element boron to calcium in the shells of ancient single-celled marine algae,” according to the online news site, ScienceDaily.
“A slightly shocking finding," Tripati said, "is that 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.”
Tripati wasn’t exaggerating about the shocking part, either.
According to the team’s findings, the last time that CO2 levels were as high as they are today, “global temperatures were 5 to 10 degrees Fahrenheit higher than they are today, the sea level was approximately 75 to 120 feet higher than today, [and] there was no permanent sea ice cap in the Arctic and very little ice on Antarctica and Greenland.”
Though it’s hardly news that today’s carbon dioxide levels are unprecedented in the last 800,000 years or so, the fact that these levels haven’t been seen for millions of years is pretty alarming.
Not surprisingly, Tripati points to the Industrial Revolution and all the carbon dioxide that came with it as the culprit for the extraordinary levels of greenhouse gas emissions.
According to Tripati, “This record is the first evidence that carbon dioxide may be linked with environmental changes, such as changes in the terrestrial ecosystem, distribution of ice, sea level and monsoon intensity.”
For example, though the Arctic Ocean is currently frozen over all year long (for now), that wasn't the case 14 million years ago, when carbon dioxide levels were similar to today's. Back then, there was no permanent sea cap.
Today, carbon dioxide levels hover at around 400 parts per million, but some predict that those numbers could increase to as much as 600 or even 900 parts per million in the next century unless CO2 reductions are made.
Many scientists advocate that carbon dioxide levels need to be reduced to 350 parts per million in order to maintain a health planet.
But that goal is looking even more unlikely as “U.N. climate talks ended in a whimper Friday without progress on the pressing issues of emission cuts for wealthy nations or financing for the developing ones, both of which are crucial to reaching a global warming pact," the Associated Press reported.
As Copenhagen looms nearer, many are crossing their fingers that meaningful climate legislation will somehow be passed this December.
Otherwise, judging by what happened the last time the atmosphere had this much carbon dioxide, we’d all better learn to swim.