The last time carbon dioxide was at this level in Mother Earth’s atmosphere, humans didn’t exist.
Just a few days ago scientists at the National Oceanic and Atmospheric Administration (NOAA) reported that carbon dioxide in the atmosphere was about to reach 400 parts per million (ppm). (Related: Global CO2 Concentrations Reaching High of 400 ppm for First Time in Human History)
“Carbon dioxide above 400 parts per million was first seen in the Arctic last year, and had also spiked above that level in hourly readings at Mauna Loa,” The New York Times reported on May 10. “But the average reading for an entire day surpassed that level at Mauna Loa for the first time in the 24 hours that ended at 8 p.m. Eastern Daylight Time on Thursday, according to data from both NOAA and Scripps.”
The Times pointed out that although summer leaves would suck about 10 billion tons of carbon out of the air in the Northern Hemisphere and bring the level below 400 ppm, it's only a matter of time before that lower summer level remains above 400.
Air bubbles interred in Antarctic ice measure a range from 180 ppm during the coldest part of the ice ages to about 280 during warm periods, with this evidence demonstrating a solid link between temperatures and CO2 levels, The Times said.
“This number is a reminder that for the last 150 years—and especially over the last several decades—we have been recklessly polluting the protective sheath of atmosphere that surrounds the Earth and protects the conditions that have fostered the flourishing of our civilization,” said climate activist and former Vice President Al Gore in a statement. “We are altering the composition of our atmosphere at an unprecedented rate.”
The last time it was this high was during the Pleistocene Era, NOAA scientist Pieter Tans told the Associated Press.
"It was much warmer than it is today," he said. "There were forests in Greenland. Sea level was higher, between 10 and 20 meters [33 to 66 feet]."
Moreover, the level is increasing 100 times faster than it was at the end of the last Ice Age, the AP said. Back then CO2 took 7,000 years to increase its saturation by 80 ppm, Tans told the newswire, but now they have risen that much in just 55 years because of fossil fuel consumption.
Although such alarming levels would seem to indicate sense of urgency is in order, governments such as those of the U.S. and China are rushing to curtail their use.
“If you start turning the Titanic long before you hit the iceberg, you can go clear without even spilling a drink of a passenger on deck,” said Richard B. Alley, a climate scientist at the Pennsylvania State University, to The New York Times. “If you wait until you’re really close, spilling a lot of drinks is the best you can hope for.”