My problem with this debate is that it is, as in almost every scientific controversy engaged in by non-scientists, waged in entirely the wrong terms.
It should come as no surprise to anyone that coming out of "the Little Ice Age" of the 1600s, global warming has occurred and is occurring. Anyone who makes even a cursory study of the climate of the past would discover that we live in one of the cooler eras of Geologic history, so warming is hardly a surprise. That addition of carbon dioxide to the air may be adding to the warming is certainly a possibility.
But set all of these things aside. Let's assume that the fluctuations are merely manifestations of Milankovich cycles, they come and they go in predictable ways. The question still boils down to--if we can avoid doing so should we be spewing noxious substances into the air, water, and land? Skip global warming--is it a good thing to burn down tropical rain forests to yield land that might give up one season or two seasons of crops?
We are facing a question of proper stewardship even absent calamity. We can do better, there are technologies for doing so. So why do we choose not to do so? Why do we mortgage our children's and their children's futures? Everything we dump into the air and water now persists for some half-life of recovery--that might be short, that might be, in human terms, nearly endless. Shouldn't we be taking steps to limit the amount of damage we do here and now? The Earth, like most humans, has remarkable recuperative mechanisms--but it is hard to recuperate from complete destruction. A tree is renewable, an entire forest is not.
It would seem that our community obligation is to protect and preserve to the best of our ability all of the goods that have come into our hands. Indeed, according to the parable of the Talents, it is our duty to foster these goods, to make them grow and to give back to God in the body of future generations more than we have been given.
These should be the terms of the debate. If we can control emissions, should we not do so? If we can find alternatives, should we not use them? If we can find means to produce less waste and preserve more of the natural world, should we not do so?
Politicians who raise the warning flag about global warming and then have energy bills in the thousands of dollars which they "offset" by purchasing "greening certificates" are doing a great deal more harm than good. You cannot offset tremendous fossil fuel energy usage by buying "green certificates." It's like sending someone else off to die in that war for you. Each person is responsible here and now for curtailing their own usage and waste--such a thing cannot be purchased from others as though it were a tradable commodity.
The reality is that I would be very surprised if Global warming were not occurring. Earth has been much warmer in the past than it is presently, and life has gotten along just fine. Multiple disaster scenarios are simply the way we seem to think in this day and age.
Christian stewardship demands of us responsible use of our own local resources and careful use of all Earth's resources. It requires that we make reasonable decisions regarding usage and conservation--neither curbing ourselves to ultra-asceticism nor squandering everything we have. We need neither to go out and hug trees nor to go out and cut them down because they are in the way of my view of the lake--but we need to find a middle road that accommodates us, our children, and the great diversity and gift of life on Earth.
And the global warming debate tends to mask the fundamental importance of these issues. It does not raise awareness, but rather focuses it improperly.