As a living planet, the species on Earth can be described as very rich, in the past billions of years, there have been continuous rebirth of species, but also the extinction of species, rebirth and extinction for this blue planet is just a normal thing.
The main reason for the extinction of a species is the change of living environment, but also by the influence of other species, and human beings as an intelligent life, for the survival of other species have a strong interference, according to the existing records, in 1600 years, the earth has been 724 species of animals and plants extinction, and the current global average of nearly 75 species per day extinction, obviously human activities have exacerbated the rate of extinction of species. What about humanity itself? Humans are also one of the species on Earth, will humans also go extinct? It is not easy to exterminate humanity.
Human beings are an intelligent life, which is fundamentally different from other species on the earth, especially with the blessing of modern technology, human beings have obtained super survivability and environmental adaptability, so human beings will not easily become extinct.
The factors that can lead to the extinction or the brink of extinction can be roughly classified into three categories, namely cosmic factors, Earth factors, and human factors themselves. First of all, let's talk about the human factors, human beings, like other creatures, there will be struggles within species because of the competition for survival resources, but the struggle between humans is obviously more terrible than other creatures, because humans apply advanced technology to the struggle, especially after the emergence of nuclear weapons, this struggle is likely to lead humanity to the brink of extinction. The threat of nuclear war to humanity is not limited to direct lethality, but also has far-reaching effects and even climate change.
When nuclear weapons explode, a large amount of soot will be thrown into the sky, because the diameter of these dust is less than the infrared wavelength, so it has a strong absorption effect on sunlight, when there are a large number of nuclear weapons in a short period of time successive explosion will change the earth's climate for a period of time, so that the earth into a cold winter, which is also known as "nuclear winter".
Of course, neither the direct killing of nuclear weapons nor the sudden climate change caused by nuclear war is enough to completely exterminate human beings with modern technology, and the belt will definitely push human beings to the brink of extinction, and the last people who can survive may be only a small part. If there is no war, can humanity sit back and relax? Not necessarily. The earth's resources are limited, the population it can carry is also limited, if the future population explosive growth, then human society may also face collapse, and then push human beings to the brink of extinction.
Although human factors are terrible, they can be prevented, and the earth factors are not what human beings can stop.
Earth is a paradise for life, but there are also hidden crises, such as the supervolcanoes under our feet. Volcanic eruptions we have all heard of, but we know that volcanoes and supervolcanoes are very different, in the history of the earth every supervolcano eruption will lead to mass extinction of organisms, for now, the United States yellow supervolcano is an active supervolcano, once it erupts, most of the United States mainland will be covered by tens of meters thick ash, the global temperature will drop 5 to 15 degrees, thus triggering a sudden change in the climate, the vast majority of human beings may be killed in this ongoing disaster, But with the blessing of modern technology, human beings should not be completely extinct.
In addition to supervolcanoes, there are also epidemics of earth.
In human history, there have been many large-scale epidemics, each of which has led to the loss of countless lives, but it is an exaggeration to say that epidemics can exterminate human beings. Any disease needs to spread from person to person, when the number of people due to the epidemic and plummeted to a certain extent, the epidemic will naturally disappear due to the decline in the speed of transmission, so the epidemic will push human beings to the brink of extinction, but can not really exterminate human beings. Whether it is human factors themselves or earth factors, it is difficult to make modern human beings completely extinct, and the cosmic factors that can really bring us ruin are the cosmic factors.
What are the cosmic factors? Asteroids? This is only the most inconspicuous of the cosmic factors.
With the existing technology of human beings can monitor the threat of asteroids, if there is really an asteroid rushing to the earth, humans can also try to change its orbit, at least can also make its impact angle change, thereby reducing the impact power, so the asteroid is difficult to completely exterminate human beings, the real danger is those wandering black holes in the universe. Not all celestial bodies in the universe have stable orbits, there are wandering planets, there are wandering stars, and even wandering black holes, if the trajectory of the solar system accidentally meets a wandering black hole, then neither the earth nor the sun can resist the gravitational pull of the black hole, then not to mention human beings, the entire earth may cease to exist.