When you look around you, almost anywhere on Earth, you see life. The earth seems extremely supportive of life: we see it in the air, in the water, on land and even in the underground depths.
But was it inevitable? We know that there have been events of mass extinction in the past, some eliminating most of life on Earth. However, since life began and spread on Earth, there has been no event that has taken place. completely eradicated life. Of course! Otherwise we wouldn’t be here to think about it.
However, it is interesting. This means that, despite severe temporary disability, the Earth’s climate has remained relatively stable for 3-4 billion years.
It’s also weird. We know that stars like the Sun become hotter as they age, and that long ago the Sun was about 30% weaker. This means that the ancient Earth should have been solid frozen, or, assuming it was lenient, the Earth should be boiling now. None is true, which is a mystery.
This is called the Faint Young Sun Paradox and has led many scientists to assume that the Earth has some kind of thermostat, a set of conditions that tend to rebalance a system that comes out of the blow so that it does not heat up too much or too much. . cold. This would be a system of negative feedback, if if a condition arises that says, say, global warming, things will change in a way that will cool it back.
But we know that there are also conditions for positive feedback. If you release too much carbon dioxide into the air, the oceans will heat up, which releases more CO2and you’ll get a feedback loop that ends badly. As we see now. And if there is too little CO2 in the air the Earth would be solid frozen.
So maybe we’re just lucky, and our environment has happened to remain stable for all those eons in which life has existed.
So is it by chance or by mechanism? Or both?
To find out, a scientist conducted an intelligent experiment. He created a simulation of 100,000 planets (!!) in which each received a set of random climate reactions, some negative and some positive, and tracked their temperatures for 3 billion years – without other variables (content of water, for example, or breathable atmosphere)) was simulated. For simplicity, he just wanted to see if a planet could maintain a habitable temperature for a long time, as Earth did.
To be clear, the simulated feedbacks were not based on real ones, such as CO2 in the air; instead, he assigned the planets at random mathematical feedback, strictly numerical situations to see what would happen. It also threw larger random changes at random times to simulate external temperature forcing, similar to things like the asteroid impact or supervolcano eruptions.
Each sim planet was then run 100 times, with variations in it slightly modified, to see what happens to the temperature.
The idea here was not to create a complete climate simulation, but to see how great a chance it plays a role in the home of a planet. He tested two hypotheses. Hypothesis 1 is that feedback has no effect, so random fluctuations govern the day; it is only a pure chance if a planet remains in a habitable temperature range for billions of years. The second hypothesis is that having feedback, either negative or positive, GUARANTEES either success or failure, with the chance that it plays no role.
In other words, he hopes to see if climate reactions are really why the Earth has been 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. Out of 100,000 planets, 9% were successful at least once (and 1,400 were successful in the very first round of 100 rounds). Some planets were successful twice, others three times … and in fact, looking at all 100,000 planets, he each had between 1 and 100 successful rounds.
But, only one planet had 100 success points out of 100. This is a robust planet, which indicates that nothing could stop it from being a beautiful place to live (and at least at temperature).
In general, analyzing the range of results and how they occurred, his conclusion is that both feedback and random chance play a role in a planet’s ability to remain within a viable temperature range. While the success rate varied from model to model, the changing factors during the 100 runs further supported the idea that both the mechanism and the chance played a role.
Apparently, wealth favors the prepared planet.
So we can extrapolate this to Earth, saying that both the feedback we have and the random chances have kept our world right, well, correct? If we unroll the box and change the circumstances a little, would we still have a habitable world to live in?
I wouldn’t go that far. This seems to support this idea, but as the author said in the paper, “The simplifications and uncertainties in the design of the model mean that it must be unrealistic in some respects. Therefore, caution is required in extrapolating from model results to reality. “
In other words, this is a very simplistic test and much more complicated tests should be done. After all, the Earth has approached the peak several times, so it’s not hard to imagine a huge asteroid impact or other factor that makes us dirty. But still, this simulation is an interesting first step!
Make a prediction: most Earth-like exoplanets will be uninhabitable, as this has happened in most of its tests. Planets like Earth were the exception. If we find it to be true, it is not so prove hypothesis, but media This one. And if we really find the most you habitable, well, that’s going to be interesting, isn’t it?
And it serves as a warning story. Not realy Know how robust the Earth is, how well it can hit and continue to continue. It has been hit in the past, staggered and shaken things up, but not without some degree of long-term environmental impact. And our own species, our civilization, is balancing on a razor right now. It would not take such a big blow to cause us unspeakable misfortune, even if the Earth’s ecosystem somehow managed to survive.
I have a lot of problems with people, but I’d rather not disappear. Uncontrolled fiddling with existing feedback seems like a pretty terrible idea to me. The earth can be robust, but we are not.
We need to be more careful. There are reasons why these things are called warning stories.