Changing earth is nothing new

Extinction Level Events are nothing new. It has been going on since the birth (or big bang) of the earth. If you believe in God, look at it this way. When God gets bored (or fustrated) with humans destroying his world, why would he not just get rid of them and try something else. He has done it before. If you don't believe in God, just consider it a timely occurance as shown by history.

What is an Extinction Level Event?
An extinction event is a period in time when a large number of species die out. The normal background rate of extinctions is about two to five families of marine invertebrates and vertebrates every million years. Since life began on Earth, this background extinction rate has been punctuated by seven major extinction events.

500 million years ago a series of mass extinctions at the Cambrian-Ordovician boundary (the Cambrian-Ordovician extinction events) eliminated many brachiopods and conodonts and severely reduced the number of trilobite species.

440 million years ago at the Ordovician-Silurian transition two Ordovician-Silurian extinction events occurred, probably as the result of a period of glaciation. Marine habitats changed drastically as sea levels decreased, causing the first die-off, then another occurred between 500 thousand and a million years later when sea levels rose rapidly.

365 million years ago in the transition from the Devonian period to the Carboniferous period about 70% of all species were eliminated. This was not a sudden event; evidence suggests that the extinctions took place over a period of some three million years.

252 million years ago, in the Permian-Triassic extinction event, about 95% of all marine species went extinct. This catastrophe was Earth's worst mass extinction, killing 53% of marine families, 84% of marine genera, and an estimated 70% of land species (including plants, insects, and vertebrate animals.)

195 million years ago, the Triassic-Jurassic extinction event eliminated about 20% of all marine families as well as most non-dinosaurian archosaurs, most therapsids, and the last of the large amphibians.

65 million years ago, the Cretaceous-Tertiary extinction event killed about 50% of all species, including the dinosaurs.

20 thousand years ago through today, humans are causing another extinction event. Hunting and overfishing have already caused extinctions and population collapses of many large land animals and fish species. Industrial development is causing habit destruction and climate changes which are bringing about the extinction of many animals and plants throughout the world.

So is there some way humans can control their possible extinction? How much control do humans actually have in their future? Do we really care enough to pursue the possibility and work to prevent it? Who knows? After all, maybe it won't happen in our lifetime.