A breathtaking view of a perfect world can easily turn into a nightmare. Our wonderful blue and green Earth is teeming with life, while Venus is a barren and sterile wasteland. The thin line that separates them is just a matter of a few degrees in temperature. A team of astronomers from the University of Geneva (UNIGE), along with the support of CNRS laboratories of Paris and Bordeaux, has achieved a landmark feat by simulating the entire runaway greenhouse process that has the power to transform the climate of a planet from idyllic and perfect for life, to a place more than harsh and hostile. The scientists have shown that even in the initial stages of the process, the atmospheric structure and cloud coverage undergo significant changes, leading to an almost-unstoppable and very complicated to reverse runaway greenhouse effect. These groundbreaking results are published in Astronomy & Astrophysics.
Too much of a good thing can turn deadly. Water vapor, a vital natural greenhouse gas, can drive a planet from an Earth-like paradise to a scorching hell with surface temperatures above 1,000°C. A little greenhouse effect is important, as it prevents Earth from becoming a frozen wasteland and keeps the temperature perfect for life. But too much greenhouse effect spells disaster, increasing the evaporation of oceans and leading to temperatures reaching several hundred degrees. “Until now, other key studies in climatology have focused solely on either the temperate state before the runaway, or either the inhabitable state post-runaway,” says Martin Turbet, researcher at CNRS laboratories of Paris and Bordeaux, and co-author of the study. “It is the first time a team has studied the transition itself with a 3D global climate model, and has checked how the climate and the atmosphere evolve during that process.”
The study also uncovers the emergence of a unique and striking cloud pattern during the process. For further information, visit phys.org.