It’s the year 2300. Extreme weather events such as building-flattening hurricanes, years-long droughts and wildfires are so common that they no longer make headlines. The last groups of humans left near the sizzling equator pack their bags and move toward the now densely populated poles.
This so-called “hothouse Earth,” where global temperatures will be 7 to 9 degrees Fahrenheit (4 to 5 degrees Celsius) higher than preindustrial temperatures and sea levels will be 33 to 200 feet (10 to 60 meters) higher than today, is hard to imagine — but easy to fall into, said a new perspective article published today (Aug. 6) in the journal Proceedings of the National Academy of Sciences. [Top 9 Ways the World Could End]
In the article, a group of scientists argued that there is a threshold temperature above which natural feedback systems that currently keep the Earth cool will unravel. At that point, a cascade of climate events will thrust the planet into a “hothouse” state. Though the scientists don’t know exactly what this threshold is, they said it could be as slight as 2 degrees C (around 4 degrees F) of warming above preindustrial levels.