As the title calls "the next mass extinction", the target is the so-called "five mass extinctions" that may have occurred in the history of the earth, and the probability of human survival is extremely high. In fact, humanity is now leading the Holocene mass extinction or the Anthropocene mass extinction, and is trying to avoid killing itself.
The "Five Mass Extinctions", or "Five Mass Extinction Events", was identified in a 1982 paper by David Locke and Jack Sekowski:
I. Ordovician-Silurian extinction events
Occurred between 445 million and 443 million years ago, about 27% of families and 57% of genera became extinct. The number of extinct genera ranks third out of five. The immediate cause is the entry of the gondwana continent into the Antarctic region, which affects the global atmospheric circulation, resulting in global cooling and a significant decline in sea level.
Second, the extinction event of the late Devonian period
Occurred between 375 million and 360 million years ago, mainly affecting marine life, about 19% of families and 50% of genera are extinct. This has lasted a long time, and the last three decades have been thought to be a possible biological cause of an ice age due to an increase in oxygen levels in the Earth's atmosphere and a significant decrease in carbon dioxide due to the massive breeding of terrestrial plants. The developed roots of terrestrial plants go several meters under the surface soil, accelerate the weathering of the rocky soil on land, release a large amount of iron and other elements into the surface water, and cause a large outbreak of eutrophication in the water system, resulting in a lack of oxygen on the seabed. Massive settlement of red tides further sends carbon dioxide from the atmosphere into seafloor sediments in batches, enhancing global cooling.
III. Permian -Triassic extinction event
It occurred 250 million years ago and is the most extinct of the five. The entire order or suborder of many animals is extinct. About 57% of families and 83% of the genera (including 53% of the families of marine life, 84% of the genera of marine life, about 96% of the species of marine life, and about 70% of the species of terrestrial life) are extinct and the only time that some damage is caused to insects. The effect on plants was small, but the tongue and sheep teeth were almost extinct, and new plant taxa began to dominate. This may be due to massive volcanic eruptions in Siberia causing massive releases of methane from combustible ice from the nearby shallow seas, as well as changes to the global atmospheric circulation and ocean current system caused by the formation of Pangea.
IV. Triassic-Jurassic extinction event
Occurred 200 million years ago, about 23% of families and 48% of the genus (including 20% of marine organisms and 55% of marine life) went extinct. It is generally believed that large-scale volcanic eruptions cause combustible ice below.
V. Cretaceous-Paleogene extinction events
Occurring between 66 million and 65 million years ago, about 17% of the families and 50% of the genera went extinct, and the number of extinct genera ranked fourth among the five, but it became famous for the complete destruction of non-avian dinosaurs. It is thought to have been caused by an impact of the Chicxulub meteorite that occurred on the Yucatan Peninsula in Mexico.
We can see the commonalities of the five mass extinctions:
Suppression of photosynthesis by shading or low temperatures strikes photosynthetic ecosystems and causes highly vegetative species to collapse.
The effect on the chemical energy ecosystem is very weak.
Limited effect on insects.
The average nutritional level of modern humans is 2.21, which is much lower than the 5.5 of the average top predator. It does not require many populations to maintain the continuation of the human species, and it is completely possible to engage in ignition synthesis producers or photosynthetic producers under artificial light in a limited number of shelters to eat, rely on water, wind, tides, nuclear, fossil fuels, new dead biomass, photovoltaics hanging on the top of the stratosphere, etc. to cultivate energy or let them play on their own in the dark, and help with catalysts on the whole point, electrolytes of suitable concentrations, and the like. Some cyanobacteria can produce organic matter in light and in the dark, and can be harvested every day. None of the above five mass extinction mechanisms seem to be enough to wipe out humans.
If the same catastrophe as the five mass extinctions above occur at the same time, the fastest is a meteorite impact, the huge volcanic eruption has a warning period of decades, the most unfavorable occasion warning period for asteroids with a diameter of 10 kilometers is one month, and humans can only make a small amount of preparations, continue to work after the successful deflection or impact to prepare for the volcano. According to the most exaggerated description of mass extinctions in recent decades, the simultaneous occurrence of the same catastrophe as the five mass extinctions above could allow the global basic night situation to last for four hundred thousand years, but even so, the equatorial poles still allow low-level photosynthesis. Less exaggerated inferences would be shortened to less than twenty thousand years.
If some volcanoes are located closer to the surface of the sea, they can try to pour seawater into their interior to cool it down to prevent eruptions. Of course, this has the potential to cause small eruptions on the spot.
The effects of cyanobacteria and plants in the mass extinction can be selectively counteracted by humans. And since termites and the like are already on Earth, there's no reason for plants to cause global cooling anymore. In fact, some scholars believe that quaternary glaciers are no less powerful than the global cooling mentioned above, but the Earth's biosphere has not suffered as much damage as in history.
The "Sixth Mass Extinction", the Holocene Mass Extinction, usually counts from the birth of human civilization, and some scientists advocate counting from the Quaternary extinction event, and some scientists propose to change the calculation from the beginning of the Anthropocene in 1950, called the Anthropocene mass extinction. Some scientists estimate that 2 million species actually went extinct in the 20th century, and the peak rate is 140,000 species extinctions per year, based on the species area curve [1]. Some studies believe that since the birth of human civilization, 83% of the biomass of wild animals and 50% of the biomass of wild plants have been destroyed by humans.
But even with 140,000 species extinctions per year, some scholars' assertion that "the current rate of extinction is the fastest in Earth's history" is clearly a false proposition — most of the species we exterminate are rainforest endemic species, which is faster than the Hyksulub meteorite hit the Yucatan Peninsula.
The large-scale ecological collapse that occurred in the ancient rainforest often left little of the fossil record.
The "likely impact" of the mass extinction can only be vaguely predicted at this time:
E.O. Wilson believes that at the rate at which humans are destroying the environment now, half of the existing species on Earth will go extinct by 2100 AD.
Regarding the formation rate of new species on the earth, the views of different scholars are very different, some believe that about 2 to 3 species per year, some believe that each mass extinction event will cause larger-scale breeding and increase species diversity, and if the extinction rate set off by humans is 20,000 to 140,000 species per year, the seeding rate of earth organisms will gradually accelerate to more than 40,000 to 180,000 species per year. In 100 years, humans may be surrounded by millions of new species of their own creation, the fastest rate of speciation in Earth's history — what you might call an "Anthropocene explosion."
In any case, scholars have watched with the naked eye the natural birth of new species such as the North American apple fly, the Italian sparrow, and the yellow-flowered York wheatgrass around them, the hybrids of European rhododendron and North American rhododendron thriving in the wasteland, and the hybrids of North American bison and domestic cattle, and the hybrids of red deer and sika deer can produce fertile offspring. Reproductive isolation has been observed in a subset of vertebrates in just 3 generations. Coral reefs are largely bleached and dead, seaweed forests are gradually retreating, while jellyfish, ctenophores, and sponges are increasing, and the sea is showing a trend of dreaming back to cambrian. It seems that not only will humans survive, but there will be many species clustered around humans.