When you look around you, almost anywhere on Earth, you see life. The Earth seems exquisitely favorable to life: we see it in the air, in the water, on the earth, and even in the depths of the earth.
But was it inevitable? We know that there have been mass extinction events in the past, some eliminating most of life on Earth. However, since life began and spread on Earth, there has been no event that completely eradicated life. Of couse! Otherwise, we wouldn’t be here to reflect on it.
Still, it’s interesting. This means that despite some severely disabling temporary events, the Earth’s climate has remained relatively stable for 3-4 million years.
This is also strange. We know that stars like the Sun heat up as they age and that long ago the Sun was 30% weaker. This means that the ancient Earth should have been frozen or else, assuming it was lenient, the Earth should be boiling now. Neither is true, which is a mystery.
It’s called the paradox of the faint young sun and has motivated many scientists to assume that the Earth has some sort of thermostat, a set of conditions that tend to rebalance a system that comes out of the shock so it doesn’t get too hot or too hot. cold. This would be a negative feedback system, in case a condition arises to, for example, heat the Earth, things will change so that it cools down.
But we know that there are also positive feedback conditions. If you release too much carbon dioxide into the air, the oceans will heat up, releasing more CO2and you’ll get a feedback loop that ends badly. As we are seeing now. And if there is too little CO2 in the air the Earth would be frozen and solid.
So maybe we are lucky and our environment has remained stable for all the eons that life has had.
So is it by chance or by mechanism? Or both?
To find out, a scientist conducted a smart experiment. He created a simulation of 100,000 planets (!!) where each was given a set of random climate feedback, some negative and some positive, and tracked their temperatures for 3 billion years, with no other variables ( water content, for example, or breathable atmosphere)) was simulated. For simplicity, I just wanted to see if a planet could maintain a habitable temperature for a long period of time, just as Earth has.
To be clear that the simulated comments were not based on actual comments like CO2 on air; instead, he assigned the planets at random mathematics comments, strictly numerical situations to see what would happen. It also caused larger random changes at random times to simulate the external forcing of temperature, similar to things like asteroid impacts or supervolcano eruptions.
Then each planet simulator ran 100 times, with its variations a bit, to see what happens with the temperature.
The goal here was not to create a complete climate simulation, but to see how great the role opportunity plays in the habitability of a planet. I tested two hypotheses. Hypothesis 1 is that feedback has no effect, so random fluctuations rule the day; it is only pure possibility if a planet remains in a habitable temperature range for billions of years. The second hypothesis is that having comments, negative or positive, guarantees success or failure, without chance having any role.
In other words, I was hoping to see if climate reactions really are the reason why the Earth has remained habitable for so long or if we are just lucky. A planet was considered habitable if its temperature remained relatively stable during the 3 billion-year simulation.
What he found is interesting. Of every 100,000 planets, 9% were successful at least once (and 1,400 were successful the first time in 100 rolls). Some planets were successful twice, others three times … and in fact, looking at the 100,000 planets, I had all the numbers between 1 and 100 successful races.
But only one planet had 100 out of 100 successful routes. This is a robust planet, indicating that nothing could have prevented it from being a pleasant place to live (and with less temperature).
In general, looking at the scope of the results and how they occurred, their conclusion is that both feedback and chance play a role in a planet’s ability to stay within a habitable temperature range. Although the success rate varied from model to model, the change in factors during the 100 tests still supported the idea that both mechanism and chance played a role.
Apparently, fortune favors the prepared planet.
So we can extrapolate it to Earth, saying that it’s the comments we have and the chance that have kept our world fair, well, Fair? If we rewind the tape and vary the circumstances a little, would we still have a livable world to live in?
I wouldn’t go that far. This seems to support this idea, but, as the same author said in the paper, “Simplifications and uncertainties in the design of the model make it unreal in some respects. Therefore, we must be careful when extrapolating the results of the model to reality.
In other words, it is a very simplistic test and much more complicated tests have to be done. After all, the Earth has sometimes approached the turning point, so it’s not hard to imagine a big impact of asteroids or some other factor that would get us dirty. But still, this simulation is an interesting first step.
He makes a prediction: most Earth-like exoplanets will be uninhabitable, as this happened in most of their tests. Planets like Earth were the exception. If we find that to be true, it does not demonstrate the hypothesis, however supports that. And if we really find it they are habitable, well, it will be interesting, right?
And that serves as a cautionary tale. We don’t really do that to know how solid is the Earth, that it may well have a blow and continue it. In the past, things have been staggered, staggered and shaken, but not without some degree of long-term environmental impacts. And our own species, our civilization, is balancing on a razor right now. It would not take such a huge blow to cause us incalculable calamity, even if the Earth’s ecosystem somehow managed to survive.
I have a lot of problems with humans, but I would rather they didn’t go extinct. An uncontrolled game with existing comments seems like a pretty terrible idea to me. The Earth may be robust, but we are not.
We need to be more careful. There is a reason these things are called caution tales.