biodiversity in warmer climates

It seems that warmth is a good thing (as in global warmth) for genetic variability and evolution. Maybe we should just let the world get warmer and see what happens. Sure we and our bodies and the environment will have to adjust, but isn't that what evolution is all about? Survival of the fittest? After reading this article and some of the others, it seems all the alarmist depressing news about the world we live in may be in fact wrong and not so drastic as each and every article make it out to be. I feel sorry for all of us who are emotional and sensitive to have to be absorbing this information all the time. Especially the children, I am sorry they have to be taught these horrible things about 99% of the fish in the sea are dying and being caught in nets for no reason and just killed bla bla bla - and the poor honeybees - all that is just so sad - and depressing - and everyone is powerless to make changes - wow it's alot to be faced with day in and day out.