The concentration of carbon dioxide reached 400 parts per million Sunday in readings taken by “The National Oceanic and Atmospheric Administration” and “The Scripps Institution of Oceanography ; the two top monitors of greenhouse gases.
the recorded values were 400.06 ppm and 400.15 ppm respectively.
Both measures came from the top of Mauna Loa volcano in Hawaii, and are considered an important bellwether for the status of Earth’s atmosphere. Readings have exceeded that milestone in the Arctic but had not reached the level in the temperate latitudes in the middle of the Pacific Ocean, far from pollution sources.
The last time Earth’s atmosphere contained 400 parts per million of carbon dioxide was more than 2.5 million years ago, during the Pleistocene Epoch. Scientists estimate that average temperatures during that time rose as much as 18 degrees Fahrenheit. Sea levels ranged between 16-131 feet higher than current levels, according to Richard Norris, a Scripps geologist.
The Scripps carbon dioxide measurements were made famous by Al Gore in his documentary “An Inconvenient Truth.” Instituted by climate science pioneer Charles David Keeling at Scripps, it represents the longest continuous record of CO2 in the world, starting from 316 ppm in March 1958.
At the current emission rate, the maximum Carbon Di Oxide limit of 450 ppm will reach in a few decades.
Source : Scripps Institution of Oceanography