This topic has been brewing in my head for some time, prompted by continuing disbelief by many that evolution has occurred and that global warming is real.
First, evolution. The vast majority of scientists "believe" evolution to be the correct explanation for the diversity of life on Earth. The figure is pretty close to 99% when one canvases scientists who actually study biology. One could view this as simply an "argument from authority" which is not powerful evidence in support of the concept. But "belief" in science implies something different. What it implies is that the scientists have examined the evidence - pro and con - and have concluded that the concept in question is the one supported by the evidence. In this case, the evidence is overwhelming in favor of evolution. You don't have to (and shouldn't) take my word for it - examine the evidence yourself. A good place to start is the "Talk Origins" website.
Now, on to global warming. We've had an unusually warm winter here in Illinois, and some folks regard this as evidence of global warming. Those folks would be making the same mistake (though with better reason) than the clown who disparaged global warming by writing to the local paper that snow on December 1st showed how global warming was not true. Here's a clue - it's not called global warming for nothing. What matters is the global rise in temperatures, not what happens at any one particular spot on the planet. This case is similar to the evolution case in that well over 90% of climate scientists regard global warming as real, and the vast majority of those would come down on the side of anthropogenic causes (greenhouse gases released by fossil fuel combustion for example). Yet many people, including people I respect, don't "believe" in global warming. Again, the climate scientists who "believe" in global warming do so because that's what the evidence shows. The rise in greenhouse gases because of industrial activities is well documented. The rise in global temperatures is also well documented. Thus, "belief" in global warming is based on evidence, not intuition or some hidden hostility to capitalism.
The rub comes when we try and figure out what to do about it, and that's why we should care about scientists' "beliefs". In the case of evolution, the continued opposition to this theory (listen to some of the republican presidential candidates) threatens science education in our country. In the case of global warming, the continued opposition to this theory has delayed the search for possible ways to mitigate the long-term effects. Because global warming has serious economic implications, it is vital that we all agree that it is a real phenomenon and that we support efforts to lessen the long-term environmental and economic impacts. Putting our heads in the sand is exactly the wrong thing to do.
