> Go back 1 billion years, and you will find that the earth has warmed and cooled far more dramatically than in the last 100 years. You're confusing a wide ran

> Go back 1 billion years, and you will find that the earth has warmed and cooled far more dramatically than in the last 100 years. You're confusing a wide range of historical temperatures with a rate of change. Today's rate of change is unprecedented. A temperature change of 10 or 20 degrees Celsius over ten million years isn't likely to wipe out species, but that same change over 500 years is much more likely to greatly reduce populations of species that cannot adapt fast enough -- including us.