Over the past several years -- and especially in the last year -- I've been doing a ton of reading about anthropogenic climate change. I am impressed by the wealth of information out there, and I'm even impressed (if that's the right word) by the amount of disinformation available. I've done my best to educate myself on the issue, and that means reading much of the sludge out there from the so-called skeptics, as well as articles from science journals. There's stuff coming out on this subject all the time, so it takes effort to stay current.
First, I'd like to say that the debate about climate change is not about Al Gore. I don't think there's any such thing as an ideal spokesperson for issues related to climate science, and if there were, it wouldn't be Gore. I do appreciate Gore's attempts to bring public attention to the issue, though, and I do appreciate his film, An Inconvenient Truth, for trying to put the science into layman's terms, never an easy feat. For those inclined to dismiss Gore's film as propaganda, I recommend reading this article, and then having a look at the science yourself. (And watch the film, if you haven't already.)
The most important work on climate change is being done by the International Panel on Climate Change (IPCC), a group of 3500 leading scientists studying the issue. Their latest (2007) report can be found here. Their work has been rigorously peer-reviewed; both the National Academy of Sciences and the joint science academies from the G8 nations have reviewed the IPCC's reports, summaries, and methodologies, and concurred with their findings. So when people talk about "consensus" in the scientific community, this is what they're talking about. Science doesn't work by consensus, so using that term is technically inaccurate -- there are always scientists who challenge the existing science, and this is a normal and healthy part of the process. What is important to note, though, is that according to the joint science academies' report, "a lack of full scientific certainty about some aspects of climate change is not a reason for delaying an immediate response that will, at a reasonable cost, prevent dangerous anthropogenic interference with the climate system." That's important to remember as you wade through the various critiques by industry-funded skeptics.
A 2004 study by Naomi Oreskes looked at all 928 articles published in science journals between 1993 and 2003 that deal with climate change. Oreskes found that not one of these peer-reviewed articles challenged the notion that the global climate is warming, and not one challenged the notion that humans are a significant cause. The fact that she focused only on peer-reviewed journals is important, as it is the peer review process, rather than some sort of contrived "consensus," that defines the way science is done. You'll see articles by global warming skeptics in The Wall Street Journal and Canadian Free Press, and you'll see them highlighted in the mainstream media, but you won't find them in refereed science journals.
This post could get really long, so I'll say that the consequences of global climate change, if we do nothing about it, will probably be severe. This will be especially true for poor, low-lying areas such as Bangladesh, which will be flooded by rising seas. If we begin dealing with the problem now, we can still maintain a stable economy while addressing the problem effectively. The longer we wait, the more difficult and more expensive it will be. In this post I suggest some ways for people to help. There are many other ways. I'm doing my part, but I can always do better. I'd be interested in your ideas, as well.