People usually imagine that life on Earth as we know it will continue indefinitely, or at least until the end of the solar life cycle. While this is of course possible, we know that it is not very likely. In fact, there are several reasons why the Earth\’s ecology could change drastically.
It is important to say here that what matters is how fast these changes will occur. The faster the changes proceed, the worse the consequences. If the Earth\’s climate changes only slowly, life will have a chance to adapt to the changing conditions. But if a catastrophe suddenly occurs, the chances of that happening are virtually nil. This is why we fear, say, an asteroid impact or nuclear war more than we fear climate change. We can cope with climate change as it progresses. We cannot cope with sudden accidents. But
The question is, how likely is such a thing to happen? For that, we can look at the statistics to date. Life has existed on Earth for about 3.5 billion years, of which about 2 billion years were spent as multicellular organisms. During that time, there have been several global extinctions, and most species of plants and animals have become extinct. For example, the proto-Permian extinction caused by elevated oxygen levels, and the Cretaceous extinction caused by asteroids. There is still about 5 billion years to go before our planet will be swallowed by the sun. Thus, it is highly likely that at least one more such event will occur.
Would such a thing mean the real end of life? It turns out that it does not. Indeed, it will take a long time to regain diversity, and it will look very different from what we know today. Still, there are things we can do to protect it.
The ideal solution would be to colonize and terraform other planets. This would ensure that whatever happens to the home planet, life as we have become accustomed to it will continue.
