It took three to four billion years for evolution to produce Homo sapiens. If the climate had failed at some point in this process even once, we might not have existed at all. Scientist demonstrates this in an exciting simulation.
The models showed that within a few million years, Earth’s climate could degrade to temperatures well below zero or near the boiling point. We also know that the sun gives out 30 percent more light since the first life on Earth. In principle, the oceans should have evaporated as a result. This did not happen.
There are two possible explanations for this. The first is that Earth somehow has some kind of thermostat, which is a mechanism that prevents the climate from rising or falling to lethal temperatures. The second option is that Earth succeeds in this through sheer luck. Out of the millions of planets that are out there, every now and then, there is one that makes them.
Toby Terrell, Professor of Earth System Sciences at University of Southampton Create a computer simulation to prove it’s part of both. It produced 100,000 planets with any combination of climate mechanisms. These are the processes that can either enhance or weaken climate change. Consider, for example, polar ice that is melting, so that it cannot reflect sunlight, but instead turns into water that absorbs sunlight, causing the Earth to warm, which in turn causes more ice to melt.
The professor started the planets “over again” hundreds of times with different initial temperatures and different climate processes, such as volcanic eruptions and meteorite impacts. All simulations tracked 100 temperatures of the planet until it became too hot or too cold for life or 3 billion years to live, which could make room for smart life.
Of the 100,000 simulated planets, only one managed to pass all 100 simulations. So he had enough climate stabilizers and enough luck. Most of the planets that have remained habitable at least once have survived less than ten times out of a hundred.
It always took luck to reach the finish line, but that in itself was not enough. After all, planets that do not have corrective climate processes remain habitable.
Our planet itself has some climate mechanisms that have a stabilizing effect, but without much of luck, we wouldn’t be there for long. For example, if a solar flare or asteroid were slightly larger or struck at a weaker time, the world would likely look very different.
Bron (nene): Science alert