British scientists are predicting global warming will cause the extinction of half the species on Earth.
I love all these scientists who seem not to conveniently forget the concept of natural selection when it suits them (i.e., only when not debunking creationism). Species adapt to environmental changes through continued survival and reproduction of members of the species with useful mutations -- that's why there are different species at all. If this wasn't the case, we'd all be the same -- protozoa.
In other words, global warming might end half of all the species that currently exist, but think of all the new species it'll create through useful adaptations!! It's strange that environmentalist scientists conceive of our planet as being in some sort of stasis where everything the way it was pre-industry is exactly how it should be. If and when the environment changes, organisms will survive through adaptation, and dying species will spin off new species, fitted with advantageous mutations for the hot, stormy, and water logged world.
This is not to say that climate change is a good thing, but simply that it could have happened (or still could happen) naturally, through weather changes, volcanic eruptions, or other geological processes. And organisms will react to it the same way they've been reacting to similar events over the past 4 billion years -- by changing. And some of that change might bring something good, or at least interesting (squirrels with gills, anyone?). After all, human civilization developed in part because of the environmental changes caused by the last Ice Age, and that turned out to be a pretty good deal for us.