We used to think that our planet is perfect.for life and we like it. On Earth there are all conditions for life to exist, flourish and develop over billions of years. We have liquid water on the surface, not very thin and not very thick atmosphere, suitable pressure and temperature at sea level. Fortunately for us, we need not only to be at a certain distance from the Sun.
Our sun can be an ordinary star, likemany others, but unlike brighter and bluish stars that are scattered across the sky, but do not live long, our Sun will shine with a relatively constant brightness of billions of years. And if the Sun shone with its constant brightness, and the Earth absorbed light during the day and reflected it at night, the laws of physics directly tell us that the temperature on the surface of our planet would be 255 kelvins (-18 degrees Celsius).
However, the average temperature is obviouslyEarth is different; Our world is much warmer than it should be, based on these calculations. The combination of cloud cover, carbon dioxide and water vapor - three things that absorb and “cover” the infrared light emitted by our planet - maintains the temperature in our world at 33 degrees Celsius. When the Earth was much younger, billions of years ago, we also had huge amounts of methane in the atom sphere, and then the planet could hold even more heat.
And although we do not believe that warming on Earth is good, billions of years ago it was necessary.
You see, when the solar system was younger,The sun was not only younger, but also colder. The star receives energy in the process of nuclear fusion in its depths: hydrogen burns to form helium. When the core heats up to high temperatures, the rate of synthesis increases, and the star burns hotter. In most cases, we think that more massive stars burn hotter (and burn their fuel more), and this is true. But as the star ages, the more hydrogen is converted into helium, the core begins to shrink. Gravitational compression emits energy, this energy has nowhere to go - it is concentrated in the core of the star - and the core heats up.
Put it all together and we will get the inevitable conclusion: as the star ages and burns more and more of its fuel, it produces more and more energy.
Today's Sun, which is 4.5 billion years old,20% more vigorous than before. If it were not for the greenhouse effect of our atmosphere, the Earth in her youth would be as cold as Mars today. But time passes, and the Sun warms up more and more. This is manifested in the scale of not hundreds, thousands or millions of years, but hundreds of millions.
Increase in solar flux by 1% will not becatastrophic, but the luminosity of the sun increases by this figure every 110 million or so. At some point - after the flow increases by 10-30%, depending on the state of our atmosphere - we will overcome the critical threshold: the surface temperature rises to 100 degrees Celsius. In other words, at some point the Sun will become so hot that the oceans of the Earth boil. This will be the ultimate form of global warming: the world will become so hot that there will simply be no more water. Life on Earth will cease to exist, although some intelligent species will still be able to stay in the upper, cooler layers of the atmosphere.
According to best estimates, this should happen later.billion-other years, although there is considerable uncertainty about how much time we have to come up with smart solutions, for example, to keep the Earth away from the Sun. We can also allow everything to take its course, knowing that when the Sun becomes a red dwarf, other worlds will become more favorable to life.
One day global warming will destroy life onEarth: not only the lives of people, but all life on the surface of the planet, including the sea. After a billion or two years, long before the Sun becomes the red giants and starts burning helium, the temperature of our world will become too unbearable for plants, animals or other living beings. Perhaps we will go to the stars, to other planets or find a place in the solar system.
Whichever way you look, we are incrediblelucky that life went on this way. If the Cambrian explosion or biological evolution would have proceeded more slowly, intelligent life would simply not have enough time to appear.