You are correct that the
climate is always changing; we constantly fluxuate between periods of
warm and
cold. This is nothing new... although these changes may not be good for humans, they aren't harmful to nature in general, and actually probably speed up
evolution by causing environmental pressures. However, this possible greenhouse warming may be different. The problem is, most ice ages or warm periods come on very slowly, over hundreds of years. Although some organisms, such as long-lived trees, may not be able to cope with this (that is why
redwoods, once very widespread, are now confined to a small part of CA), most organisms can change and adapt to the changing climate. Supposedly, climate change caused by
humans would be much faster.
Another factor is that we are putting carbon into the atmosphere that hasn't been there since the day of the dinosaurs. If you look at the climate of those days, it was very hot, wet, and swampy. This might be good for dinosaurs, but it isnt for humans, who tend to do best in temperate forests and grasslands. Also, there are too many of us, and not enough room as it is. I don't for a second doubt that a sudden ice age would do just as much harm as a greenhouse warming. But, we shouldn't work to cause either.
While i agree that crazed ravings about the evils of technology get us nowhere, i fail to undrestand why we keep relying on oil from unstable countries or fragile ecosystems when we could run our cars guilt free off of agricultural ethanol. Our country produces lots of corn surplus as it is.. converting this to ethanol fuel would not be a problem.. and it would cease our reliance on the Middle East. Also, it will not increase the amount of carbon dioxide in the atmosphere, because the carbon in the fuel was just pulled out of the atmosphere via the plants. So... we could drive as much as we wanted or could afford, without increasing CO2
Why don't we use this technology now? Well, it seems obvious... the oil companies refuse to research it, and bury it in nonsense, because they find so much profit in the current fossil fuel oils. My truck can run on ethanol, but even in davis, a very 'liberal' city, I can't find ethanol sold anywhere. Although some say Al Gore might place too many restrictions on automobiles, it is obvious that Dubbya will support the oil companies. It is too bad that people dont realize that technology (humans) can coexist with the earth quite well with a bit of effort.