If the human race gets extinct, what will happen to the earth?

ByNASA Goddard Space Flight Center

Human beings are the only creatures on the earth who can make big changes such as building a river, creating artificial islands in the ocean and making the mountains flat, and changing the terrain and environment of the earth. If such a human being came out of the earth, what will happen to the earthAsapSCIENCEIt is explained in the movie.

What If Humans Disappeared? - YouTube


If people are gone from the earth, the chaotic condition will continue for the first few weeks.

First of all, when humans disappear, power plants run out of fuel within a few hours and the operation stops. Because of that influence the light will disappear from the city and the enclosure fence will no longer make sense, so that more than 1.5 billion cattle worldwide, about 1 billion pigs, 20 billion chickens and other domestic animals seeking food To get out of the barn and the fence.


As no one feeds animals, most of the livestock will starve and die, or it will be dogs with over 500 million dogs worldwide or cats considered to be of the same number.


However, artificially modified breeds of dogs and cats are not suitable for living in the wild and can be expected to become targets, perhaps more robust mongrel dogs, wolves, coyotes, wildcats etc.


In addition, rats and cockroaches will greatly reduce the number of individuals by eliminating humans, so that organisms such as human louse and head lice will be extinct.


Many famous boulevards in the city become rivers ... ...


Because the electric pump will not operate, the subway will be submerged.


And the streets and buildings will be covered with weeds and ivy, large plants and trees will grow.


However, before the city is submerged and covered with vegetation, it seems likely that many cities will be thoroughly destroyed by "fire". This is because many woods are used in modern houses, especially in suburban houses, once the fire has arrived at the house by lightning, the area will be burned down.


Meanwhile, wood in rural houses will also be destroyed within several decades. This cause is not "fire" but "termite" and otherDecomposerIt seems that there is a high possibility of a crime by.


If 100 years have passed since humans are gone, most wooden buildings will be gone. And the remainder are the foundation of the building and the steel used for the car etc.


However, these will corrode as soon as possible. Steel, for example, mostly made of iron, rusts with oxygen as soon as there is no coating on the surface, so these lifespan seems not so long if there are no people.


And hundreds of years after human beings are gone, most animals around the world will return to the standard of living before human beings are born. However, only the habitat distribution of organisms is expected to remain changed by humans, such as camels living in Australia, many birds imported from Europe to North America, and lions on Great Plains It is predicted that such things as inhabiting and hippopotamus in South America occur. The reason why such a thing happens is that animals escaping from zoos worldwide will form a new ecosystem as it is.


In addition, electromagnetic waves emitted from radio, satellite, telephone, etc. will remain permanently on the earth as what remains after human beings are gone.


Chemical binders such as plastic and sulfurized rubber are not affected by digestive enzymes used when bacteria and others decompose substances. So, unlike metals, plastics rust, will not corrode. Since these substances will not disappear, they will remain on the earth either by floating in the water or floating in the sea or burying them in the earth.


Of course, what is left on the earth and what goes away depends greatly on the environment, but in the desert more stuff remains for a long time. This is because there is less "moisture" in the desert to promote corrosion and support decomposition. There is also the possibility that the carbon cycle has returned the level of carbon dioxide to the level several thousand years ago.


In addition, organic chemicals and radioactive materials seem to remain on the earth for a long time.


It is quite a surprising result that it is only human beings that have changed their hands will disappear one after another.