THE HIGHEST CO2 CONCENTRATION

FOR 3 MILLION YEARS

The concentration in the atmosphere of CO2 is at its highest for 3 million years, making the dramatic rise in global temperature and ocean levels unavoidable in a few centuries, warns researchers.

In fact, researchers have taken ice cores and marine sediments from the coldest part of the planet. The result is cold in the back:

the current level of carbon dioxide, a little over 400 parts per million (ppm), is the highest since 3 million years!

So far, the current level of carbon dioxide was no greater than that of 800,000 years ago, during a period marked by warming and cooling cycles of the Earth that would continue unabated. way today without the warming related to human activities.

Where the rub is the exceeding of the bar of 400 ppm that back to 3 million years back during the Pliocene.

Why ?

At that time at higher temperatures of 3 to 4 ° C, trees were growing in Antarctica and the ocean level was 15 meters higher!

"The end of the Pliocene is relatively close to us in terms of CO2 levels," said Matteo Willeit, researcher at the Potsdam Institute for Climate Impact Research (PIK), lead author of the study

"Our models suggest that in the Pliocene there were no glacial cycles or large ice caps in the northern hemisphere. The CO2 was too high and the climate too hot to allow it. ".

What about the Paris agreement on the 2015 climate?

If it aims to limit global warming to + 2 ° C, or + 1.5 ° C, compared to the pre-industrial era in 2017, greenhouse gas emissions exceeded all records in human history!

The commitments of the signatory states of the Paris agreement would lead the world towards + 3 ° C.

Based on the CO2 concentrations, glaciologists predict an increase in ocean level between 50 cm and one meter by the end of this century, says the researcher.

"It would be difficult to be more, because the melt takes time. But it does not stop at 2100, it continues.

There are lessons to be learned from the Pliocene.