FORBES - Man-made greenhouse gases have long been a hot button topic here on earth since as pollutants, they are largely responsible for anthropogenic climate change. But what about alien civilizations that intentionally use greenhouse gases to save their planet from the onset of a snowball earth type situation; that is, a completely ice-covered planet? Or to terraform a frozen desert-like planet, not unlike Mars? Or even to stave off the effects of a long period of planetary glaciation?
In a paper to appear in The Astrophysics Journal, the authors outline the rationale in looking for the technosignatures of such artificial greenhouse gases in the atmospheres of far-flung planets.
We outline two scenarios where artificial greenhouse gases could produce a detectable signature, Edward Schwieterman, the paper’s lead author and an astrobiologist at the University of California, Riverside, told me via email. The first would be if an alien civilization were to terraform an otherwise uninhabitable planet in their planetary system, as humans have proposed for Mars, he says.