Although sun radiation was relatively low, the temperature on the young Earth was warm. An international team of geoscientists has found important clues that high levels of carbon dioxide in the atmosphere were responsible for these high temperatures. It only got cooler with the beginning of plate tectonics, as the CO2 was gradually captured and stored on the emerging continents.
Very high atmospheric CO2 levels can explain the high temperatures on the still young Earth three to four billion years ago. At the time, our Sun shone with only 70 to 80 per cent of its present intensity. Nevertheless, the climate on the young Earth was apparently quite warm because there was hardly any glacial ice. This phenomenon is known as the ‘paradox of the young weak Sun.’ Without an effective greenhouse gas, the young Earth would have frozen into a lump of ice. Whether CO2, methane, or an entirely different greenhouse gas heated up planet Earth is a matter of debate among scientists. New research by Dr Daniel Herwartz of the University of Cologne, Professor Dr Andreas Pack of the University of Göttingen, and Professor Dr Thorsten Nagel of the University of Aarhus (Denmark) now suggests that high CO2 levels are a plausible explanation. This would also solve another geoscientific problem: ocean temperatures that were apparently too high. The study has now appeared in the Proceedings of the National Academy of Sciences.
Read more at: University of Cologne