Global Warming

I found the abstract of a research paper reporting studies of temperature in the Alps. The researchers find that the temperatures between 800 and 1300 were comparable to today's temperatures. This is one of the big problems I've always had with the global warming theory. The supporter will show graphs indicating the temperature of the Earth (whatever that means) has been rising, and at an increasing rate, in recent decades. This, they say, supports global warming. But showing climatic variation does not prove global warming. We know that the Earth's climate changes over time. These are changes purely driven by natural forces. Global warming requires more than simply showing the "temperature" is increasing. Global warming says the temperature is increasing because of greenhouse gases in the atmosphere from the burning of fossil fuels and other causes. Therefore, we have to differentiate climatic variations due to natural changes in solar output or whatever from variations due to greenhouse gases.

A few years ago, I watched an old In Search Of from the 70's warning that climatic variations were indicating a coming ice age.