A recent geological analysis of atmospheric carbon dioxide levels yielded alarming results about the future. The study carried out covers the last 66 million years and shows that currently the level of CO₂ is the same as it was about 14 million years ago. Only in that remote era, the fault was not of humans, as it is today.
The result of the research was published in the journal Science. It was done by scientists and researchers at Columbia University in New York. They report that the last period when carbon dioxide levels were this high was between 14 and 16 million years ago.
Currently, the concentration is approximately 420 parts per million. Contrary to previous belief, the study indicates that this level is not on a time scale of 5 or 6 million years, as science thought until now.
The study was developed over 7 years of geological analysis and involved more than 80 scientists and researchers from 16 countries. According to Baerbel Hoenisch, coordinator of the study, this analysis gives a more solid idea of how the climate evolved over long periods of time.
CO₂ levels are comparable to those of very remote times
In times before the industrial revolution, the CO₂ concentration level was 280 ppm. With human activity it increased by 50%, which also caused a 1.2 degree increase in global temperature.
The alarming thing is that, if current emissions continue, the level of CO₂ concentration in our atmosphere could reach between 600 and 800 ppm. These high concentration rates are only comparable to those of the Eocene period, that is, about 30 or 40 million years ago. This happened before Antarctica was covered in ice.
It must be taken into account that man began to evolve only about three million years ago. For this reason, humans never experienced such extreme levels of heat on the planet.
How did you carry out the research?
To reconstruct such remote times, the team of researchers used a well-known technique. They recovered air bubbles from the depths of the polar caps that were trapped millennia ago. These bubbles, in turn, trapped air containing the composition of the atmosphere of ancient times.
Additionally, they explored geological retreat in greater depth by using indirect indicators. They analyzed the chemical composition of ancient plant leaves, minerals, plankton and other elements, making it possible to reconstruct events that occurred millions of years ago.
Of the 66 million years involved in the analysis, the Earth is known to have had its warmest period about 50 million years ago. Throughout that time, the concentration of CO₂ was 1,600 parts per million. Temperatures were therefore about 12 degrees higher than today. The problem is that it took the planet 150 thousand years to recover.
About 2.5 million years ago, levels decreased during the Ice Age, where the CO₂ concentration was between 270 and 280 ppm.
