if they can do it, why can’t we?


So why don’t we see advanced civilizations swarming across the Universe? One problem may be climate change. It is not that advanced civilizations always destroy themselves by over-heating their biospheres (although that is a possibility).

Instead, because stars become brighter as they age, most planets with an initially life-friendly climate will become uninhabitably hot long before intelligent life emerges. Other inhabited planets in the Universe must also have found ways to prevent global warming.

Watery worlds suitable for life will have climates that, like the Earth, are highly sensitive to changing circumstances.

The repeated canceling of star-induced warming by “geobiological” cooling, required to keep such planets habitable, will have needed many coincidences, and the vast majority of such planets will have run out of luck long before sentient beings evolved. However, the Universe is immense, and a few rare worlds will have had the necessary good fortune.

It may just be that Earth is one of those lucky planets—a precious, fragile jewel in space. So, perhaps inevitably, climate change will remain a bane of the continued existence of life on such planets. ars technica, 10 Jun 2014