The statement that Earth has another 500 million years left before becoming a microbial-only planet is based on scientific estimates of the future habitability of our planet. However, it's important to note that the future of humanity and our ability to survive for such an extended period is subject to a wide range of factors and uncertainties. While 500 million years is a very long time frame, there are several reasons why it is highly unlikely for humans to survive that long:
Natural Catastrophes: Over such an immense time span, the Earth is likely to experience various natural catastrophes such as supervolcanic eruptions, asteroid impacts, or other significant events that could have devastating effects on life, including human civilization.
Climate Change: While Earth's climate has naturally fluctuated throughout its history, human activities have significantly accelerated climate change in recent centuries. If we don't take adequate measures to mitigate its impacts, climate change could lead to severe consequences for human civilization in the coming centuries.
Technological Risks: As technology advances, so do the potential risks associated with it. Humanity faces potential dangers from nuclear weapons, biotechnology, artificial intelligence, and other rapidly developing technologies. A single catastrophic event or misuse of advanced technologies could have disastrous consequences.
Resource Depletion: As the human population continues to grow, there is an increasing strain on Earth's resources, including water, arable land, and energy sources. Unsustainable consumption and resource depletion may lead to societal collapse or conflicts.
Space Threats: The Earth is vulnerable to space threats, such as large asteroids or comets, which could cause widespread destruction and disrupt life on the planet.
Evolution and Adaptation: Over the course of millions of years, organisms on Earth undergo evolutionary changes. Human beings, as they exist today, may not be suited to survive in the far future if the environment drastically changes.
Unknown Unknowns: There are many unknown factors and variables that could come into play over such an extended period, making it challenging to predict the fate of humanity accurately.
While it is essential to consider the long-term sustainability of our species and the planet, making predictions about events hundreds of millions of years into the future is fraught with uncertainty. Our focus should be on addressing the immediate and pressing challenges facing humanity today, such as climate change, resource management, and sustainable development, to ensure a better future for generations to come.