While I am not a philosophical skeptic (I do believe that knowledge is possible), I am a practical skeptic (I require proof before I believe). While some folks are skeptical of climate change, the evidence seems adequate to support the claim that humans have had a measurable impact on the climate. Given the scale of human activity, this seems inherently plausible. The climate data and causal explanations also seem fairly compelling.
Naturally, there are skeptics regarding climate change. Some of these folks are rational skeptics. That is, their doubts are founded on legitimate concerns about the methodologies used in climate science as well as the data in question. This sort of doubt and skepticism is actually a rather important part of the scientific approach: just as Socrates argued for the importance of the gadfly in the context of society, there should also be gadflies in science. Scientists are, after all, only human and are subject to all the same cognitive biases and frailties as everyone else (plus are especially vulnerable to certain biases).
Some folks are, however, irrational skeptics. They base their doubt not on legitimate critiques of the methodology or the data. Some of these folks base their doubt not on logic, but on their emotions. They feel hostility towards the idea of climate change and the people who claim it is real. They feel positive towards the folks who deny it. However, feeling is not a good guide to the truth. John Locke argued quite effectively for this in his essay regarding enthusiasm. However, you can test this yourself: try taking a chemistry test or solving a complex engineering problem solely by how you feel about the matter. Let me know how well that works out. To be fair, there are folks who believe in climate change based on how they feel. While I am inclined to say that their belief is correct, I am even more inclined to say that they are not warranted to hold said belief since it is based on feeling rather than on actual reasons.
Some of the skeptics base their doubt on the fact that the truth of climate change would be contrary to their interests. In some cases, they are not consciously aware that they are rejecting a claim based on this factor and they might very well be sincere in their skepticism. However, this is merely a form of wishful thinking. Other folks are well aware of what they are doing when they express their “skepticism.” Their goal is not to engage in a scientific debate over the matter-that is, engage in argumentation to achieve the truth. Rather, their objective is to persuade others to doubt climate change and thus protect their perceived interests. To be fair, there are folks who push climate change because doing so is in their own interest. As Al Gore will attest, there is considerable money to be made in this area. This, of course, does not show that Al Gore is wrong-“reasoning” this way would be to fall victim to a circumstantial ad homimem fallacy. Saying that the climate change deniers are wrong because they have an interest in denying it would also commit this fallacy (the sword of logic cuts both ways).
Interesting, while whether climate change is occurring or not (and whether or not it is our doing) is a scientific matter, much of the fighting is done in the realm of politics and rhetoric. However, factual claims about climate are not settled by who has the best rhetoric or who can get the most votes. They must be settled by scientific means. As such, it is important to cut through the rhetoric (and fallacies) and get to the heart of the matter.
While the consensus of the experts is that climate change is real and is caused, at least in part, by humans, I am not an expert on climate change. But, I am rational and, as such, I will accept their view unless adequate contrary evidence is provided from unbiased sources.