Actually, I'm a scientist and I don't believe it is scientific fact. (Biologist - physiology not environmental science. But non the less I have access to many of the published literature and have been trained to analyze papers critically, thoughtfully, and logically.)
Yes our climate does seem to be changing. Is it due to pollution? Is it due to sun spots? Is it part of a cyclic change our planet has gone through throughout history? Is it a combination of things? Is it something we don't know about yet?
Honestly, there is not enough data at this point to really know. And really there is no way to get that data without a couple of hundred or maybe even thousands of years more data recorded and analyzed.
I do think it's a reasonable and logical conclusion that our actions are effecting our environment. I do believe it is important to study and try and figure out why and how our environment is changing so we can deal with those changes. I also don't even think there is any harm in believing in global warming. Especially, if it motivates us to clean up our air, water, and planet and be aware of our use of resources and our waste.
But do I believe in global warming? I'm very skeptical.