I personally believe that global warming is the catastrophe du jour. In the 80s, it was global cooling. In the 90s, it was the hole in the ozone layer. Some climatologists have found a slight warming trend since such things were recorded. Recently, certain politicians and activists have claimed that this warming trend is caused by human being's use of carbon-based resources. On the other hand, some paleoclimatologists have found a cyclical trend over many centuries, which would mean that humans have nothing to do with it.
The thing to be wary about in this debate is that each side has an agenda and investments.
I personally believe that the "global warming" issue isn't really that important. However, there are related issues that are important to our lifestyle. First, we need to achieve energy independence. By relying on certain unsavory characters for our oil, we are putting ourselves, as a country, in a very risky position economically. Not only that, but researching and developing alternative fuels and energy sources just adds to our choices as consumers. However, energy independence also includes keeping independence from global, even national, organizations who dictate what a country's "carbon footprint" should be. We go from dependence on one side of the debate to dependence on the other.
Another issue is one which we Scouts should be especially involved in, environmental responsibility. We are by far the biggest users of American backcountry. Every year, this backcountry is damaged, even destroyed, by carelessness, development, and ignorance. As we teach and live by the principles of LNT, we can become better stewards of the environment.
In all, we need to be wary of who we throw our support behind. We need to be vigilant in studying out the evidence and decide for ourselves what makes sense. Not necessarily what someone else tells us. (For example, I read an article today about an environmental think tank suggesting that the entire world should adopt China's laws regarding offspring all in the name of global warming.)