It seems to me that when scientists predict something for 50-100 years, it is basically “a finger in the sky”, but to predict something for a long time ahead on the basis of about the same period already passed, a more accurate forecast is possible.
For example, what is expected to happen to our planet in 5 billion years. The Earth is 4.54 billion years old. These data are based on radioisotope dating of meteorite samples (chondrites) that formed before the formation of planets. And if approximately the same period of time passes?
With humanity, the devil only knows, but with the Planet itself?
Warmer, even warmer
Not many scientists predict a cold snap for our planet in the coming decades. Most are confident that global warming will continue. According to the most conservative estimates, in a hundred years this will lead to an increase in the level of the world ocean by a meter and a half. But in a thousand years, entire cities will go under the water: New York, Washington and Miami - as these have already disappeared. Even countries like Holland, Maldives and Bangladesh could disappear. More details "My Planet" wrote in the article "New Atlantis".
Coastal residents will have a hard time, but these are just flowers. "Berries" can be expected for all the inhabitants of Europe, who are now heated by the Gulf Stream - a current that "works" on the temperature difference between the equator and high latitudes. If, thanks to global warming, this difference decreases, according to some climatic models, the “hot water bottle of Europe”, according to some climatic models, may turn into an ice bubble in a century - at least it will heat up less, or even stop altogether. This threat especially concerns such a northern country as Great Britain, in the main part of which, according to all accounts, should not be warmer than in Siberia.
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Rising temperatures are already expanding the Sahara Desert further north, turning Morocco's once fertile lands to dust. Unsurprisingly, it all takes its toll on animals. Due to the rapid melting of ice, the population of polar bears, polar foxes and emperor penguins is declining. But trouble awaits not only the northern fauna, but also the southern one - for example, koalas, pandas, gorillas and beautiful pink flamingos, which will sooner or later be completely extinct.
Planet fever
Global warming does not mean that we have said goodbye to ice ages. Cooling and warming cycles on Earth occur at intervals of 100,000 to 20,000 years and are caused by changes in the parameters of the planet's motion around the Sun, the tilt of the Earth's axis, and other complex reasons. What awaits us in the next 50,000 years?
First of all, the fluctuations of the world's oceans. Periodic changes in temperature will lead to the fact that it will go down and then rise, so the continents will either shrink or grow again. Over the next 20,000 years, for example, ocean levels will drop and the US East Coast will expand further eastward - instead of large bays from Boston to Miami, only dry plateaus will remain. Alaska will be connected to Russia by an ice-covered isthmus, and from the British Isles to the mainland, as thousands of years ago, it will again be possible to go by land.
If you look further into the future - 100,000 years - you can see the contours of the continents even more changed. But that's okay. Much more serious is the threat of large volcanic eruptions. According to some theories, they occur with a frequency of about once every 30 million years. But one of such gigantic eruptions - the Taupo volcano in New Zealand, which ejected 830 km³ of lava and ash - occurred 26,500 years ago. Volcano Toba in Sumatra exploded even earlier - 74,000 years ago, spewing out 2800 km³ of lava. Far away from us? Very. But it is this eruption, for a minute, that is associated with the peak of one of the ice ages and thus the "bottleneck" (a decrease in the population to a critical size, close to the extinction of the species), through which our ancestors passed. The thickness of the ash from the Toba volcano in Malaysia was then 9 m,and in distant India - 6 m!
Wind and space aliens
Stones are wears away not only by water, but also by the wind. Oddly enough, but in a million years it will cause the world map to be slightly different from today's (the aforementioned ocean fluctuations will also contribute to this, and the shift of continents, which by that time will have shifted 45-60 km from the current location). This will especially affect the ocean shores.
For example, some volcanic islands or Calvert County, in the southern part of Maryland (USA) - its rocky coastline will completely "erode" after 50,000 years. Other countries, on the contrary, will acquire new territories. Among the lucky ones is Hawaii, in the area of which there is a young active volcano, which has already risen to 3000 m, although it is still hidden under water. And in a million years there will be a full-fledged island here. He was even given a name - Loikhi (after the name of the volcano itself).
At regular intervals, not only megavolcanoes erupt - scientists have calculated that once every tens of millions of years, large asteroids, like the one that finally crippled the life of dinosaurs 65 million years ago. Humanity in its entire history (extremely short in geological terms) has not yet encountered space aliens. But it will certainly collide. When is unknown. In 2029, the famous asteroid Apophis, 325-340 m in diameter, will deeply enter the orbit of the Moon, and on its next return will pass even closer to Earth. And then again and again. Scientists predict that such an alien should crash into our planet in the next 50 million years. What will happen to humanity in this case is better not to know.
What does the letter L have to do with it
In the past, continents have repeatedly disintegrated and reunited, forming a single supercontinent. Today these parts of the once broken "saucer" again tend to each other. Slowly but surely - by 2–5 cm per year. So after 20 million years, the world map will have to be redrawn - the Atlantic Ocean will become wider by several hundred kilometers, and the Pacific Ocean, on the contrary, will narrow by about the same distance. Australia will move north to South Asia. And in several tens of millions of years Africa, already today moving towards Europe, will finally cover the Mediterranean Sea, forming mountains of such height in this place that the modern Alps seem to be only a yard palisade. The new mountain range will stretch from the Atlantic to the Indian Ocean. The Atlantic itself, by the way, in 100 million years will become larger than the Pacific Ocean. Supercontinent formation will be in full swing,but how it will look, scientists do not yet know.
There are two main versions. According to the first, the Atlantic Ocean will continue to expand, causing both Americas to collide with Asia, Australia and Antarctica. Then North America will cover the Pacific Ocean and collide with Japan, and South America will be hooked, connecting with Antarctica. The continent that stretches from east to west along the equator is called Novopangea.
The second version: both America will face Europe and Africa, and Australia and Antarctica - with Southeast Asia. You will get a super-continent in the shape of the letter L, which has fallen on its back, - Amazia.
Heatstroke
The sun is warming up. It is a fact. 4.5 billion years ago, when our planet appeared, its luminosity was 70% of today's. 2.4 billion years later - already 85%, in 1 billion years our star will become even brighter.
The oceans will start to evaporate. Glaciers will disappear completely, the poles will turn into tropics. At the same time, life can still be healthy. But the merciless "yarilo" will still not retreat - as it warms up into space, hydrogen will evaporate, drying the Earth and turning it into a desert.
And then the reserves of hydrogen on the Sun itself will be depleted, which means that in 5 billion years it will begin to die. And it will do it beautifully - it will expand, absorbing first Mercury, then Venus, and then it will reach Earth. Scientists disagree on whether it will absorb it completely or only come close to orbit. But even in the most optimistic scenario, the luminary will burn our once blue planet to ashes, turning it into a firebrand, on the surface of which not only apple trees, but even mold in a jar will never bloom. But deep in the bowels of the microorganisms can remain for another billion years.
Used materials from the book by Robert Hazen "History of the Earth. From stardust to a living planet"
Author: Alga Fadeeva