I saw Senator Tom DeLay on MSNBC the other night. He mentioned that it was "arrogant" for humans to think we can affect the global climate. I'm not exactly sure where he came up with that, usually that kind of terminology is code for religious fundamentalism--'God put us into this world, God'll take us out.' I was surprised. I figured that after George W. Bush had finally acknowledged global warming, that the nay-sayers were a thing of the past.
In truth, it is not proven that the burning of fossil fuels and modern agriculture are the causes of global climate change. Yes, a change is happening. Of that, there is no doubt. But the cause(s) remain scientifically unproven. There is a bounty of evidence that global warming is linked to human activity--the rise in temperature corresponds to the usage of fossil fuels which took a sharp increase at the beginning of the Industrial Revolution. As compelling as statistics like that are, it is still technically unproven.
We need to understand the way science works, though. If you all remember back a few years, there was a major debate as to whether or not smoking causes cancer. Cynics and skeptics mocked science and railed against any allegation that smoking causes cancer. For sure, big money slowed down the process. Yet, the evidence was staggering that smoking causes cancer, but in a purely scientific way, it was not technically proven until recently. In order for science to prove something, it has to isolate a variable and show in clear view that this one variable led to this one outcome, and then to repeat that on a statistically large enough test group. When you consider all the thousands and thousands of chemicals acting upon your body--every scrap of food you eat has hundreds of chemicals in it--you can imagine how difficult the task is for science to break it down.
When the evidence starts to build up as drastically as it has been in the cases of smoking and global warming, we need to act as if it is true. Just using your common sense, you could see that the lung cancer ward at the hospital is filled with people who smoke. Smokers just seem to have breathing problems. There is a ton of correlational evidence that smoking is linked to cancer. Sure, you can find the odd person who lives to 90 years old as a chain smoker, but one or two examples might actually prove the rule rather than discount it.
I'm not suggesting we change everything we do at every hypothesis that science throws our way. That would be impossible to do, anyway, since science is not one unified body--it is often a plurality of voices with contradictory opinions. But something like global climate change is a very big deal, bigger than most people even imagine. The scientific community is either at or approaching concensus that global warming is due to human activity. We really don't know how bad it can get, but we are already surpassing science's worst case scenarios for the stage we're currently in. A lot of people, however, seem to believe what they want to believe rather than what the evidence tells us. This is the hard discipline of science--letting yourself be guided by truth rather than your own desires. I encourage people to look through evidence in a detailed way. Call science on the carpet. Scientists need to be checked so that they don't let their assumptions or predispositions drive them, because they are vulnerable to the same tendencies as the rest of us.
If you went to a restaurant and the waiter brought you a plate of chicken, what would you do if the waiter said: "Someone thinks that this chicken was thrown into the garbage can, and that someone retrieved it and put it on your plate. However, some of us are not sure. It has not been proven that it ever went near the garbage can." I can tell you what I would do: I would not eat the chicken! I see no reason to take that kind of chance.
If we live in a world where millions of people believe fervently that an activity is dangerous, I am the type of person to heed that warning and refrain. Whether science is not entirely sure about the cause or not is really not entirely consequential to me--I am going to act as if it is true, until science proves that there is no reason to be concerned. Science is busy working on the problems of our day, but it may be generations before we get answers to some of our most pressing questions. We need to figure out what we are going to do in the meantime. I certainly don't want to be huddled under my blankets and afraid to face the world because somebody thinks there's a risk here or there. But we need to figure out what to do in situations where science does not have an answer. If someone thinks there's a good chance my dinner came right from the garbage can before it ended up in my plate, I can tell you that I am not going to eat it despite the fact that it is not yet "proven". I am going to act as if it is true. Whether that means cleaning the chicken, re-cooking it, feeding it to the dog, or simply throwing it out. I am going to make my decision in light of the very real possibility that is has been tampered with.
Maybe its an urban legend that standing next to a running microwave puts you at risk of dangerous levels of radiation exposure. However, it costs me little time and energy to stand at a distance from running microwaves. If it turns out to be untrue, then I'm not really any worse off for being careful. However, if it turns out to be true, I will be glad I took steps to protect myself.
We shouldn't be run by our fears, and we shouldn't let ourselves be swayed by every hint of allegation or suspicion out there. Somebody, somewhere, has a warning for just about everything you could possibly do. However, science has some very strong theories about certain things, with quite a bit of correlational data. There are some issues that I feel are too important to wait for science to prove.