A Hot Earth Is Normal

Some Like It Hot Humans may struggle to survive in hot weather, but the planet does just fine. In fact, the Earth existed in a greenhouse climate free of ice caps for much of its history and only developed its ice caps through a lucky coincidence. A new study shows that ice caps formed due to a fortunate combination of low global volcanism and widely dispersed continents with large mountains, which facilitated global rainfall, and enhanced processes that remove carbon from the atmosphere, said researchers at the University of Adelaide in Australia. “The important implication here is that the Earth’s natural climate regulation mechanism appears to favor a warm and high-CO2 world with no ice caps, not the partially glaciated and low-CO2 world we have today,” explained Andrew Merdith, lead author of the study. Researchers believe Earth’s general tendency towards a warm climate has generally prevented catastrophic “snowball Earth” glaciations, allowing life to prosper. Researchers have long tried to explain the cold intervals in Earth’s history by following clues such as decreased CO2 emissions from volcanoes, the reaction of CO2 with certain rocks, and increased carbon storage by forests. Now, researchers were able to conduct the first comprehensive test of all these cooling processes using a new long-term 3D Earth model developed because of advances in computing. The team concluded that no single process could create these cold climates and that the cooling was produced by the combined effects of several processes that took place at the same time. “Over its long history, the Earth likes it hot, but our human society does not,” said co-author Benjamin Mills, adding that this study carries implications for global warming and that we should not always expect Earth to return to the cooler climate of the pre-industrial age.