Please name your source that says the temperature has risen 10 degrees in less than 300 years. I've consistently seen just over one degree in the past century. Assuming fossil fuels have something to do with it, one can safely assume that it was less in the century before that, and still less before that. Thus we can probably place the rise in temperature at less than 2.5 degrees. You also have to keep in mind that there was a mini-ice age in the Middle Ages. Also keep in mind that we are still recovering from the ice ages of 10,000 years ago and earlier. The world is normally warmer than it is now. We're stuck in a giant cold spell, and I doubt leaving it will kill us all.

Perhaps the 10 degrees in 300 years is for the U.S.A. only. In that case, the rest of the world has less cause for concern and has likely warmed even less than the 2.5 degrees I estimated above since the U.S.A. is one of the largest producers of greenhouse gases.

Also, if the world has indeed been warming by a significant amount from at least 300 years ago, which is before the Industrial Revolution, then humans cannot take all, or even most of, the blame for global warming. This means that it's probably part of the natural cycle of warming and cooling that has been going on for billions of years. I would also like to point out that climate change is included among the theories of the causes for some of the several mass extinctions that have occurred throughout earth's history, indicating again that this is nature at work, and humans cannot be blamed for it all. Of greater concern is probably the clear-cutting of forests and inefficient use of space.