more system measuring the concentration of CO2 in the air has passed the symbolic threshold of 400 ppm (parts per million) as reported on Friday the National Oceanic and Atmospheric Agency U.S.. UU. (NOAA, its acronym in English), a level not seen for millions of years.
Studies on the volcano Mauna Loa in Hawaii (Pacific) showed a concentration of 400.03 parts per million (ppm) on Thursday . The measure of air quality over the Pacific Ocean is currently considered “preliminary”, according to NOAA. According to the Scripps Institute of Oceanography in San Diego also still healing from 400 ppm , showing in its latest statement on Thursday the figure of 399.73 ppm.
These measurements are one of the reasons most famous of the case against the man’s role in global warming . From the first steps, adjusted to 316 ppm in 1958, the curve has increased continuously. Until the Industrial Revolution and the massive use of fossil fuels, the rate does not exceed 300 ppm for at least 800,000 years, according to the polar ice samples.
“The last time the world had a concentration of 400 ppm CO2 was about three million years ago, when global temperature was two to three degrees higher than pre-industrial era,” said Bob Ward, communications director of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and Political Science.
A “prehistoric environment”
“The ice caps were smaller and the sea level was about 20 meters higher than today.’re creating a prehistoric environment in which our society will face a huge and potentially catastrophic risks,” he added.
target set by the international community is to contain global warming to 2 ° C above pre-industrial levels, the threshold beyond which scientists warn that the climate system will be out of control, with consequent extreme.
However, 400 ppm CO2 is already being the world on the road to an increase averaging 2.4 degrees , according to the latest report by UN experts on Climate Change (IPCC). “We can reduce carbon dioxide levels by reducing global emissions,” added Bob Ward. According to Michael Mann, a climatologist at Penn State University, the main problem is the rate at which CO2 concentrations increase.
“There is no precedent in the history of the Earth, where there has been a sharp increase in the concentrations of emissions of greenhouse gases “, told AFP. “Nature needed hundreds of millions of years to change the concentrations of CO2 through natural processes such as carbon burial. And we do digging, but not for 100 million years. We dug up and burned on a scale of 100 years, a million times faster, “says Mr Mann.
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