Mourning the Death of The Scientific Method
What irks me most concerning the debate about global warming is the lack of clarity that occurs when lay people proffer opinions as a de facto substitute for a methodology of structured inquiry that has quite literally brought mankind out of the caves and forests, into a much more sophisticated style of life.
The heart of the scientific method is as follows:
1. Observe some aspect of the universe.
2. Invent a tentative description, called a hypothesis, that is consistent with what you have observed.
3. Use the hypothesis to make predictions.
4. Test those predictions by experiments or further observations and modify the hypothesis in the light of your results.
5. Repeat steps 3 and 4 until there are no discrepancies between theory and experiment and/or observation.
Where we've gotten sidetracked in this whole debate is at the point of sorting out the discrepancies. We're talking about an observed phenomenon (global warming) that by itself is deceptively simple and straightforward, but which is one outcome of a highly complex and interactive set of variables. There are three major groups of variables - vivocentric variables (man-made and bovine CO2 production, arboreal O2 production and bacteriologic nitrogen fixing are all good examples here); geocentric variables (volcanic eruptions, seasonal albedo variablity and plate tectonics are good examples here); and finally, exoplanetary variables (perturbations in Earth's orbit and mean solar output are good examples of these variables).
The problem I have with global warming rhetoric is that it puts the cart squarely ahead of the horse. The truth is that we have yet to produce a comprehensive theory that accounts for all of the variables. This is not particularly surprising because I'm not sure that we can even identify all of the variables involved in determining climate. But, nonetheless, in our anthropocentrist style, we seem all too content to stop at the point of blaming ourselves. This in spite of the fact that our current explanations fail to adequately explain the reality of previous climate changes. I'm referring, of course, to the climactic variability that has occurred over the 99.9999 +% of the planet's history during which mankind didn't exist.
That is a very important point - before we go willy-nilly suggesting solutions, isn't it reasonable to thoroughly understand the full nature of the problem? In the worst case, taking action based on incomplete or inaccurate theories could well have unintended and far-reaching consequences that are negative in some other way. I was taught as a lad that the point of the scientific method was to get definite, provable and repeatable results, and then take action. Much in the same vein as medicine's first rule: primum non nocere - do no harm, we need to understand what we're doing, not just act.
Many of the "compelling evidence" pieces cited in popular articles are based on computer generated predictions of mean global temperature change that are based on a few variables (few relative to the total number of variables). There is no proof that they are the key variables, and there is no evidence presented that the interactions between them have been correctly modeled. As anyone who has done a bit of 'what-if' modeling can attest, one can produce a huge number of outcomes given incremental changes to each of the variables. I suppose that if given free access to a supercomputer, I could come up with some pretty graphic presentations of the globe heating up and cooling down as well as the next chap. To the extent that I'm better educated than the average person, it might serve as persuasive evidence to others that it's "the answer" - but then again it might just be pretty pictures that I got from one of my millions of 'what-if' simulations.
I think most of us have seen studies that purport to "prove" a point using correlation as the key argument in their proof - hemlines and the stock market is a commonly cited example. The weakness inherent in this methodology, however, is that it fails to unequivocally establish a causal link - it merely establishes a statistical link. Much of what is passing for science is thinly disguised correlative work that neither proves or disproves anything. If you think that correlative works constitute adequate proof, then explain for us the causal link between NYSE changes and hemlines, please.
It's a shame that this issue has become politicised and emotionalised to the degree that it's become a market sector unto itself with a life all it's own - just ask Mr. Gore about the ways he's profited from beating the global warming drum; just ask the owners of all those media outlets, whether print, electronic or web, about the myriad ways they've profited by bleating about global warming. It's unfortunate for us all that our scientists, both pro and con, have been hijacked by the politicians and media around them to such a degree that we no longer have scientific dialogue and discourse over global warming, in their places we've accepted screed and hate-mongering.
There's nothing rational or sensible about the current state of affairs. I don't know what the final outcome of the current observed trend toward higher mean global temperatures will be, but I do know that standing on opposite sides of a picket line shouting expletives at one another isn't doing a damn thing to advance our understanding of and ability to deal with climate change. Dealing with climate change is the real heart of the issue here - we do know that the planet has been significantly warmer, and significantly cooler than it is today. It's safe to assume that the real constant in the history of climate is not its stability, but its variability. Therefore, it's also safe to assume that our future survival depends on understanding the whole climate model, not just parts of it. Whatever the outcome of the current trend, it is evident that we need to use our proven scientific method of analysis and discovery to keep ourselves alive into the future - not the loud "sky is falling" vs "head in the sand" debate.
-Geoff
Biting the hand that feeds IT
