Scientists at the University of Southampton found that the Earth’s climate is going to move for a few million years in the past. By 2025, the levels of carbon dioxide in the atmosphere reached record levels over the past 3.3 million years. This is caused by human activity. This was reported in an article published in the journal Scientific Reports.
The researchers analyzed the chemical composition of fossils collected from deep sediments of the Caribbean sea. The obtained data were used for the reconstruction of carbon dioxide concentrations in the Earth’s atmosphere about three million years ago, during the Pliocene (from 5.3 to 2.8 million years ago) when the Earth was three degrees warmer than today. Then the polar cap occupied a smaller area, and the sea level was higher.
To estimate ancient carbon dioxide concentration, scientists have determined the ratio of boron isotopes in the remains of the shells of foraminifera. The isotopic composition depends on the acidity of sea water, and that, in turn, from the carbon dioxide in the atmosphere.
It turned out that the warmest period of the Pliocene carbon dioxide concentration in the atmosphere reached 380-420 ppm. This compares with the current value equal to 415 parts per million. It shows that humanity has reached a level at which there are significant climatic changes. It is estimated that by 2025, the carbon dioxide will exceed all values for the last three million years. It also means that in the future levels more likely to reach record levels over the past 15 million years.
