When you look around, you can see almost anywhere on the planet. The earth seems to be very supportive of life: we can see it in the air, in the water, on land and even deep underground.
But is it inevitable? We know that there have been mass extinctions in the past, some of which have wiped out most life on Earth.However, since life began and spread on the earth, there have been no events completely Annihilate life. of course! Otherwise we would not think about it here.
However, this is interesting. This means that despite the occurrence of some serious impotent temporary events, the earth’s climate has remained relatively stable for 300-400 million years.
This is also very strange. We know that stars like the sun get hotter with age, and long ago, the sun was about 30% darker. This means that the ancient earth should have been frozen as a solid, or assuming it was Clement, then the earth should now be boiling. None of it is true, this is a mystery.
This is known as the faint young sun paradox and has prompted many scientists to speculate that the earth has some kind of thermostat, a condition that tends to rebalance an out-of-control system so that it does not become too hot or too hot. cold. This will be a negative feedback system. In this case, if something happens, such as making the earth warm, things will change in a way that changes how they cool.
But we know that there are also positive feedback conditions. If you release too much carbon dioxide into the air, the ocean will warm up and release more carbon dioxide.2, You will get a feedback loop that will fail severely. As we see now.If CO is too little2 In the air, the earth will be frozen as a solid.
Therefore, maybe we are just lucky, and our environment happens to remain stable for all such long lives.
So is it accidental or mechanism? Or both?
To find out, the scientist conducted a clever experiment. He created a planet that simulates 1
To be clear, analog feedback is not based on real feedback (such as CO)2 In the air; instead, he randomly assigned the planets mathematical Feedback, strict numbers, and see what happens. He also randomly generates large random changes to simulate external forcing of temperature, which is similar to an asteroid impact or a supervolcanic eruption.
Then each planetary simulation ran 100 times, and the changes in it were changed to see what happened to the temperature.
The purpose here is not to create a complete climate simulation, but to see how much opportunity plays in the habitability of planets. He is testing two hypotheses. Hypothesis 1 is that the feedback has no effect, so random fluctuations determine the day; if the planet maintains a habitable temperature within the temperature range of billions of years, it will be a complete opportunity. The second hypothesis is to get positive or negative feedback, Guarantee Regardless of success or failure, opportunities do not work.
In other words, he wants to know whether climate feedback is really the reason why the earth can live for a long time, or whether we are lucky. If the temperature remains relatively stable during the 3 billion years of simulation, the planet is considered habitable.
His findings are very interesting. Among 100,000 planets, 9% succeeded at least once (in the first of 100 planets, 1400 succeeded). Some planets succeeded twice, about three times as long… In fact, from the perspective of all 100,000 planets, his number of successful operations is between 1 and 100.
However, only 100 planets have successfully orbited. This is a robust planet, showing that nothing can prevent it from becoming an ideal habitat (and the lowest temperature).
Overall, looking at the scope of the results and the way they occur, he concludes that both feedback and random chance have an impact on the planet’s ability to stay within the habitable temperature range. Although the success rate varies from model to model, changing factors in more than 100 runs still supports the view that both mechanisms and opportunities are at work.
Obviously, wealth prefers prepared planets.
So, can we extrapolate it to the earth, saying that this is the feedback and random opportunities we have to keep our fair world, fair? If we rewind and change the situation a bit, do we have a habitable world?
I will not go that far. This seems to support this idea, but as the author himself said in the paper: “The simplification and uncertainty of model design means that it must be unrealistic in some respects. Therefore, you need to be cautious when inferring from model results to reality. .”
In other words, this is a very simple test and more complex tests should be performed. After all, the earth has been close to the critical point several times, so it is not difficult to imagine that a huge asteroid impact or some other factors make us dirty. However, this simulation is still an interesting first step!
It did make a prediction: most exoplanets similar to the Earth will be uninhabitable, because this happened during most of his tests. Planets like the earth are an exception.If we find that it’s true, it’s not prove Suppose, but stand by it.If we find the most true Yes It’s habitable, that would be fun, wouldn’t it?
This is a warning story.We are not real know How strong the earth is, its ability to withstand impacts, and its ability to move forward continuously. It has been slammed, staggered and shaky in the past, but it is not without a certain degree of long-term environmental impact. Now, our own species, our civilization is balanced on the edge of the razor. Even if the earth’s ecosystem survives in some way, it will not bring us huge disasters.
I have many questions about mankind, but I hope we will not be extinct. I was shocked by uncontrollably fiddling with the feedback that already existed. It was a very bad idea. The earth may be strong, but it is not.
We need to be more careful.These things are called for a reason Warning story.