In this blog post, we will look at the various threats to humanity’s extinction and explore ways to overcome them through science and technology and 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 gone extinct. The reasons for the extinction of living organisms are diverse. They may have been wiped out by predators or have failed to adapt to changing habitat environments. It may have been a natural disaster such as an asteroid impact or a genetic problem such as a mutation. The important thing is that even the most prosperous species will eventually disappear. This is a natural law.
However, a species has appeared on Earth that can defy this natural law. This is the human race, which evolved from apes about one million years ago. They have “intelligence” that other living beings do not have, which has enabled them to develop science and technology and to escape many extinction risks. Humans devised tools to overcome physical limitations and climbed to the top of the food chain, freeing themselves from the threat of predators. They also created clothes, housing, and irrigation systems, enabling them to adapt to all regions of the world. Even today, human science and technology are developing rapidly, and the development of science and technology is further increasing the chances of human survival.
However, it is still too early to conclude that humanity has completely escaped the natural cycle of extinction. This is because a catastrophe that is incomparable to the crises that have occurred so far awaits humanity. These disasters will shake the very essence of human life and drive humanity to the brink of extinction. If humanity is to overcome this and survive, it must have the scientific and technological capabilities to prevent disasters. In the following, we will look at what disasters threaten the survival of humanity and what kind of science and technology is needed to overcome them.
The extinction of men, 120,000 years later
In order for a living organism to maintain its species, it must produce offspring that resemble itself. In this process, the parents’ genes are replicated and passed on to their offspring. However, the process of gene replication is not perfect, and there is a certain probability that mutations occur, causing the genetic information to gradually disappear. Human autosomes exist in pairs, so even if the genetic information of one chromosome is damaged, it can be replaced by exchanging some of the genetic information with the opposite chromosome. The problem occurs in the sex chromosomes. Women have XX sex chromosomes and men have XY sex chromosomes, but in the case of men, the Y chromosome does not have a pair to exchange genetic information with. Therefore, mutations that occur in the Y chromosome are not cured and continue to accumulate. If this process continues, at some point the Y chromosome will no longer function, and humans who inherit the XY chromosome will be born as women. At this point, humans will no longer be able to reproduce and will go extinct. If we calculate the cumulative rate of mutation of the Y chromosome, it is predicted to be about 120,000 years later. If humans do not develop a technology to control the mutation of the Y chromosome or find a way to reproduce without the Y chromosome by then, they will have no choice but to go extinct.
The extinction of plants, 100 million years later
In the early Cenozoic Era, the main components of the atmosphere were methane, ammonia, and carbon dioxide, making it an unsuitable environment for animals to live in. However, during the evolution of life, plants emerged that absorbed carbon dioxide and released oxygen. As plants thrived, the concentration of carbon dioxide in the atmosphere gradually decreased. As a result, the Earth now has the right levels of carbon dioxide and oxygen for life to thrive, and the Earth’s biosphere is enjoying its heyday.
However, this plant growth will not continue. The trend of decreasing carbon dioxide in the atmosphere will continue, and at some point, there will no longer be enough carbon dioxide left to support plant photosynthesis. This will lead to the extinction of most of the multicellular plants that exist today in about 100 million years. If plants are to go extinct, ecosystems will collapse in a chain reaction, and multicellular organisms, including humans, will disappear from the Earth’s biosphere. To prevent the extinction of plants, humanity must maintain the Earth’s atmospheric composition at a constant level. To do so, we need technology that can intervene in the global material cycle and artificially control all processes, and through this, we must continuously maintain the composition of the Earth’s materials so that it does not become a planet unsuitable for life.
The disappearance of the ocean and atmosphere, 700 million years later
The reason why a planet can have an atmosphere is because the planet’s gravity holds gas molecules to its surface. However, over time, gas molecules gradually escape into outer space, and at some point, the planet’s atmosphere disappears. Considering the current rate of atmosphere loss and the future environment of the Earth, the point at which the Earth will lose its atmosphere is predicted to be about 700 million years from now. As the atmosphere evaporates and the atmospheric pressure decreases, the evaporation of water vapor in the ocean also accelerates, and when the atmosphere disappears, the ocean will disappear as well. When the ocean disappears, the flow of heat within the Earth will stop, and the movement of the plates will also stop. The Earth will become a dead star. It is difficult for humans to control the escape of gas molecules on a planetary scale. Therefore, we must continue to supply water, oxygen, and other resources to Earth. Many comets in the outer solar system contain abundant resources such as water, methane, and oxygen. If we can continue to supply these comets’ gases to Earth, we may be able to prevent the disappearance of the atmosphere and oceans.
The sun’s extinction, 6 billion years later
The sun that shines on the earth also has a finite lifespan. Main-sequence stars, which are similar in size to the sun, gradually swell as they approach the end of their lifespan and become red giants. In about 3.5 billion years, the surface temperature of the earth will rise to over 100 degrees due to the expansion of the sun, and the earth will no longer be able to support life. After 5 billion years, the sun will expand to the orbit of the Earth and swallow it up. In this series of processes, humans must move their orbiting Earth outwards to survive. If a comet with a diameter of about 100 km repeatedly brushes against the Earth, the comet’s kinetic energy will be transferred to the Earth, and the Earth’s orbit will gradually increase. By repeating this process, we can move the Earth’s orbit to the current position of Mars, where it will survive safely from the red giant Sun in 5 billion years.
But it is too early to be relieved. Even after becoming a red giant, the Sun will continue to burn and explode 6 billion years from now, using up all its hydrogen and becoming a white dwarf. During this explosion, everything in the solar system will be blown away. If humanity does not have the ability to migrate to another solar system before this moment arrives, it will meet its end with the sun. However, if humanity finds a planet in another solar system that is habitable and has enough time, resources, and technology to migrate to it, it will be able to survive once again.
Conclusion
We have introduced the various disasters that must be overcome to prevent the extinction of humanity. In order to survive these disasters, humanity’s science and technology must advance. If the greatest purpose of living things is to ensure the survival of their species, then humans 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 a lot of resources. Science and technology should not be restricted by political logic, economic feasibility, etc. and should be treated with priority over other values. We must not forget that science and technology are directly linked to the survival of humanity.
