Is it cold in here, or is it just me?
In what is sure to be a shock to Mr. Gore, it turns out that the scientific community actually is divided on the topic of human influences on the Earth's climate. It seems that over 17,000 (translation - LOTS) scientists have signed a petition online (see it here) stating their skepticism over the idea that the changes seen in the Earth's temperature over the last 100 years or so are actually due to the activities of the human race.
Now, there are a couple of caveats here. First, we have to recognize that just because someone is an expert in one scientific endeavor (say, computer science) does not mean that they are an expert in climatology as well. They may have a better understanding of the methodology used by climate researchers, but interpreting the results takes a great deal of knowledge about the topic at hand. Of course, this criticism applies to both sides of the argument, never forget.
Second, pointing to an isolated event and claiming that it disproves or proves the case for global warming is a serious mistake. Given that the weather in various parts of the world can vary significantly within a short period, a severe snowstorm in the midwest no more disproves global warming than a warm winter in New Jersey proves it. When we talk about global climate change, we are really talking about long term trends - 10 winters in New Jersey might with above average temperatures might be a good start on an argument there.
This is, I think, the heart of the issue that these 17,000 scientists are concerned about. Researchers on both sides of the argument have shown an alarming tendency to pick and choose the data that they use to justify their positions (witness the IPCC report, which will be "adjusted" to match the executive summary - how's that again? We pick our conclusions and then massage the data to match?). The scientific method demands, instead, that we apply rigorous standards to our research - if the data does not fit our hypothesis, its time to develop a new hypothesis that matches the data, rather than throwing out the data.
Sadly, there may never be a resolution to this argument, even when we get to the next century and get a chance to look back on what actually happened with the climate. Somehow the global warming advocates have managed the impossible - everything is a result of global warming now. Summer to hot? Global warming. Winter too cold? Global warming. Sea level too high? Global warming. Sea level too low? Global warming. Its a fun game - pick a topic and try it!