Warm seas when the Earth was still young?

Andreas Pack has studied the composition of the isotopes of rocks from the Earth's early history in Götttingen University's Isotope Laboratory Photo: Dennis Kohl Researchers from the Universities of Göttingen, Cologne and Århus calculate the water temperatures of the first oceans For decades, there has been controversy about the water temperatures of the first oceans on Earth. At that time, radiation from the Sun was much weaker and the oceans could have been very cold, perhaps even frozen. On the other hand, the very dense carbon dioxide (CO₂) atmosphere could have caused an extreme greenhouse effect, which might have led to ocean temperatures of around 70 degrees Celsius. Three scientists from the Universities of Cologne, Göttingen and Århus have now combined their research about the development of our atmosphere with that of the rock crust and seawater temperatures. They have calculated temperatures of about 40 degrees Celsius in the early period of the Earth. The results were published in the scientific journal Proceedings of the National Academy of Sciences. "The atmospheres of Earth and its sibling Venus have developed in very different directions over the last 4.6 billion years," says isotope geologist Professor Andreas Pack from the University of Göttingen.