Upcoming telescopes will give us more power to search for biosignatures on all the exoplanets we’ve found. Much of the biosignature conversation is centred on biogenic chemistry, such as atmospheric gases produced by simple, single-celled creatures. But what if we want to search for technological civilizations that might be out there? Could we find them by searching for their air pollution?
If a distant civilization was giving our planet a cursory glance in its own survey of alien worlds and technosignatures, they couldn’t help but notice our air pollution.
The pandemic caused by the novel coronavirus is creating all kinds of chaos for human society. But for the dear old Earth, and the humans and creatures that breathe its air, it’s a bit of a reprieve. Mirroring what happened in China during lock-down, Europe is now seeing the same drop in air pollution.