Earth managed to “stay on the knife’s edge”:
In a new study, Professor Toby Tyrrell, a specialist on Earth system science at the University of Southampton, set out to shed light on how our planet has managed to remain habitable, and to what extent luck may have played a role in its continued success.
To this end Professor Tyrrell used the Iridis supercomputing facility located at the University of Southampton to model 100,000 randomly different worlds. He then simulated how their evolutionary paths, and therefore their temperatures, were affected by climate-altering events over the course of three billion years.
The evolution of each digital planet was simulated 100 times, and for each run different random events were inflicted upon the worlds.
It was discovered that out of the 100,000 planets, only one was able to maintain habitability for all 100 of its simulations. The remaining worlds that were able to maintain a temperature suitable for sustaining life for three billion years were only able to do so in some of their simulated histories, and thus had a probability of being habitable rather than a certainty of it.Anthony Wood, “Study calculates how lucky we are to have a habitable planet” at New Atlas (December 14, 2020)
“It was discovered that out of the 100,000 planets, only one was able to maintain habitability for all 100 of its simulations.” Sounds like winning a hundred lotteries in a row. Luck? Naw.
Paper. (open access)