I've talked about belief before, mostly in a religious/political sense. Scientific belief is quite a bit different in that science isn't so much a "belief" as "I agree X is the best explanation for Y because the weight of data/scientific evidence convinces me it is true." I shorten this to belief for the sake of brevity, but it's really quite different than testimony, which is what I talk about when I reference religious belief, or social/economic/governmental conviction, which is (at least closer to) what I'm talking about with regard to political belief.
Why do I bring this up? Because in a scientific way I believe in global warming and wish there were a better way to express that than to say I believe in it. I am convinced global warming is happening because numerous proxies, including borehole temperature profiles, tree rings, corals, and many others, show the surface temperature of the Earth is higher now than it was a couple of centuries ago. I am convinced our output of greenhouse gases--CO2 and methane primarily--is changing the composition of the atmosphere, and those changes are causing the temperature to increase. Demonstrably shorter and warmer winters, changing habitat ranges for many species, shrinking glaciers--all point to a world that is getting warmer.
Now to my beliefs--I don't believe a warmer world is a bad thing, though I would be sad to loose glaciers and pika, and the pine trees that I associate with the mountains in the west. There are certainly things that will be better, and things that will be worse. I believe it is our reaction to the changes that are going to happen that will determine whether the warmer world we are creating will be a better or a worse one. Which is why I hope the discussion moves swiftly from "is this happening" to "what are the consequences we're going to face."