The last time the average level of carbon dioxide in the atmosphere was equal to its current values was 14-16 million years ago, according to the authors of a study published on Friday in the scientific journal “Science”. Researchers warn against further increases in greenhouse gas emissions.
As indicated by the findings of a group of 80 scientists from 16 countries around the world, the last recorded average carbon dioxide concentration of 420 ppm in the atmosphere occurred 14-16 million years ago, and not 3-5 million years ago, as previously thought. This discovery “makes us realize that what we are doing is truly unique in the history of the Earth,” says lead author Baerbel Hoenisch, quoted by Live Science. The scientists reached these findings by analyzing previously published work by other researchers and comparing them with the latest data.
– The species Homo sapiens evolved only three million years ago, notes Hoenisch, adding that for this reason “our civilization is adapted to the sea level we have today, to the warm tropics, cool poles and temperate regions where there is a lot of rainfall.” “. Further increases in the average concentration of carbon dioxide may cause the climate to develop completely differently.
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The last time CO2 levels were this high was 14 million years ago
If global CO2 emissions continue to increase, carbon dioxide concentrations in the atmosphere could reach 600-800 ppm by 2100. The last time such high levels occurred was in the Eocene, about 30-40 million years ago. Antarctica was not yet covered with ice at that time, and the fauna and flora found on Earth were completely different from what we know today, scientists point out.
As academics note, in the period from about 2.5 million years ago to the end of the 18th century, the average CO2 concentration in the atmosphere was about 280 ppm. Since the beginning of industrialization, humans have already caused an approximately 50% increase in greenhouse gas emissions. This resulted in an increase in the average global temperature by 1.2 degrees Celsius. Further increases in carbon dioxide emissions can only make this worse.
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