In this blog post, we will examine various threats to human extinction and explore ways to overcome them through science and technology to make the Earth sustainable.
Natural laws and human survival
In the natural world, the birth and extinction of a species is a natural occurrence. Since the first life forms appeared on Earth 3.8 billion years ago, countless species have been born and become extinct. There are many reasons for the extinction of life forms. They may have been wiped out by predators or failed to adapt to changes in their habitat.
Natural disasters such as asteroid collisions or genetic issues such as mutations may also play a role. The important thing to remember is that no matter how prosperous a species may be, it will eventually disappear. This is the law of nature. However, a species capable of defying this natural law has emerged on Earth. This is humanity, which evolved from primates approximately 1 million years ago.
Humans possess intelligence, which is unique among living beings, enabling them to develop science and technology. Thanks to this, humans have been able to avoid many extinction threats. Humans invented tools to overcome physical limitations, rose to the top of the food chain, and escaped the threat of predators. Additionally, humans created clothing, shelters, and irrigation systems, allowing them to adapt to all regions of the world.
Today, human science and technology continue to advance rapidly, and this progress is further enhancing humanity’s chances of survival. However, it is still too early to conclude that humanity has completely escaped the natural cycle of extinction. This is because disasters of an unprecedented scale, incomparable to any crises we have faced so far, lie ahead. These disasters will shake the very foundations of human life and push humanity to the brink of extinction.
In order for humanity to overcome these disasters and survive, we must possess scientific and technological capabilities that can prevent them. In the following section, we will examine what disasters threaten the survival of humanity and what scientific and technological capabilities are necessary to overcome them.
The extinction of men in 120,000 years
In order for living organisms to maintain their species, they must produce offspring that resemble themselves. In this process, the parents’ genes are replicated and passed on to their offspring. However, the process of gene replication is not perfect, and mutations occur with a certain probability, causing genetic information to gradually disappear. Human autosomes exist in pairs, so even if the genetic information on one chromosome is damaged, it can be partially exchanged with the opposite chromosome to fill the gap. The problem arises with sex chromosomes. Females have XX sex chromosomes, while males have XY sex chromosomes. In males, the Y chromosome has no counterpart to exchange genetic information with. Therefore, mutations that occur on the Y chromosome are not repaired and continue to accumulate. As this process continues, the Y chromosome eventually loses its function, and individuals inheriting the XY chromosomes are born female. At this point, humanity will no longer be able to reproduce and will become extinct. Calculating the rate of mutation accumulation on the Y chromosome, this is predicted to occur in approximately 120,000 years. If humanity fails to develop technology to control mutations on the Y chromosome or discover a method of reproduction without the Y chromosome by that time, humanity will inevitably face extinction.
Extinction of plants, 100 million years later
In the early geological era, the atmosphere was composed mainly of methane, ammonia, and carbon dioxide, making it an inhospitable environment for animals. However, during the course of evolution, plants emerged that absorbed carbon dioxide and released oxygen. As plants flourished, the concentration of carbon dioxide in the atmosphere gradually decreased.
As a result, Earth now has the appropriate levels of carbon dioxide and oxygen for life to thrive, and the Earth’s biosphere is in its prime.
However, this proliferation of plants will not continue indefinitely. The trend of decreasing carbon dioxide in the atmosphere will continue, and at some point, there will no longer be enough carbon dioxide to sustain photosynthesis in plants. As a result, most multicellular plants similar to those we see today will go extinct in as little as 100 million years. The extinction of plants will trigger a domino effect, causing ecosystems to collapse, and multicellular organisms, including humans, will inevitably disappear from Earth’s biosphere. To prevent the extinction of plants, humanity must maintain a constant composition of the Earth’s atmosphere. This requires technology capable of intervening in global material cycles and artificially controlling all processes, ensuring that the Earth’s material composition remains suitable for life.
The disappearance of oceans and atmosphere, 700 million years from now
Planets can have atmospheres because their gravity holds gas molecules to their surfaces. However, over time, gas molecules gradually escape into space, and at some point, the planet’s atmosphere disappears. Considering the current rate of atmospheric loss and the future environment of Earth, it is predicted that Earth will lose its atmosphere in approximately 700 million years. As the atmosphere gradually evaporates and atmospheric pressure decreases, the evaporation of water vapor from the oceans accelerates, and when the atmosphere is completely gone, the oceans also disappear. When the oceans disappear, the heat flow within the Earth stops, and even the movement of tectonic plates comes to a halt. In essence, the Earth becomes a dead planet. Humans have little control over this planetary-scale escape of gas molecules. Therefore, water and oxygen must be continuously supplied to Earth. Numerous comets existing in the outer reaches of the solar system contain abundant resources such as water, methane, and oxygen. If the gases from these comets can be continuously supplied to Earth, humans may be able to prevent the loss of the atmosphere and oceans.
The death of the Sun, 6 billion years from now
The life of the Sun that shines on Earth is also finite. Main-sequence stars similar in size to the Sun gradually expand as they approach the end of their lifespans, becoming red giants. Approximately 3.5 billion years from now, the Sun’s expansion will cause Earth’s surface temperature to rise above 100 degrees Celsius, rendering it uninhabitable. By 5 billion years from now, the Sun will have expanded to encompass Earth’s orbit, engulfing the planet. To survive this process, humanity must gradually move Earth’s orbital path outward. By repeatedly causing comets with a diameter of about 100 kilometers to graze Earth, the comets’ kinetic energy is transferred to Earth, gradually increasing its orbital distance. Repeating this process can move Earth’s orbit to the current position of Mars, where it can safely survive the red giant phase of the Sun 5 billion years from now.
However, it is too early to feel secure. Even after becoming a red giant, the Sun will continue to burn until it exhausts all its hydrogen in 6 billion years, exploding into a white dwarf. In this explosion, everything in the solar system will be obliterated. If humanity does not acquire the ability to migrate to another solar system before this moment arrives, it will meet its end alongside the Sun. However, if humanity discovers another planet in another solar system where it can live, and if it has sufficient time, resources, and technology to relocate there, it will be able to survive once again.
Conclusion
In this article, we introduced various disasters that humanity must overcome in order to avoid extinction. In order to survive these disasters, humanity must advance its science and technology. If the ultimate purpose of life is the survival of the species, humanity must develop science and technology to ensure the survival of the human species. Therefore, humanity must encourage the development of science and technology and invest significant resources in it. Science and technology should not be restricted by political logic or economic considerations but should be prioritized above other values. We must never forget that science and technology are directly linked to the survival of humanity.
