Global Warming Skepticism Reason 3: It's Only a Theory

One of the objections raised in the Global Climate Change debate is that it is "only a theory" so we should not take any drastic steps based on it. I have examined this premise and what it means to be a theory, and how that should affect one's thinking about this important issue.

First, let's examine what it means to be a theory. According to the American Heritage Dictionary of the English Language a theory is:

"A set of statements or principles devised to explain a group of facts or phenomena, especially one that has been repeatedly tested or is widely accepted and can be used to make predictions about natural phenomena."

Hmm, to me that sounds like a theory can be a pretty useful thing! What caught my eye was the phrase "repeatedly tested or is widely accepted." So by this definition, calling Global Climate Change a theory actually gives it a lot of credibility. When people attempt to disparage an idea by calling it a theory, I think they are confusing this term with "hypothesis". A hypothesis, according to the same dictionary, is:

"A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation."

It is interesting to note that another famous theory is being disparaged by skeptics by using that term, and that is the theory of natural selection (more commonly known as evolution). Religious zealots who want biblical passages taught in public schools say that evolution is "only a theory" and they attempt to elevate the biblical creation story to the same level by calling it "intelligent design." When you look at the definitions, I would have to call "intelligent design" at best a hypothesis and certainly not a theory. When looking at all the evidence and studies contributing to global change theory, I would say that it is a pretty strong theory and certainly more than a mere hypothesis.

Consider this-- gravity is a theory too, but does that stop you from taking actions based on it? When you walk to edge of a cliff, do you not stop short of the edge because you expect (predict) that gravity will cause you to fall if you go further? In a very real sense, that is analogous to scientists saying that continued increases in activities that put more carbon dioxide and other greenhouse gasses into our atmosphere will lead to continued global average temperature increases and the associated problems that would result from it.

It is also the case that theories often are refined as more studies are done and more evidence is discovered. This does not make them wrong in the first place. In fact, the "laws" of gravity and Isaac Newton's laws of motion, which are actually theories, were refined later by Einstein's theories of relativity. But that did not make these theories any less useful for making predictions before those refinements. (Einstein's refinements only have a significant impact when things are moving at near the speed of light.) So for example, uncertainty over things like whether sea levels will rise 2 feet in the next 50 years or 5 feet should not make us doubt the general premise of climate change theory-- that certain human activities are causing our climate to change in ways that will have a variety of impacts on life on this planet.

Reference:
American Heritage Dictionary of the English Language (Fourth Edition, 2000). online at: www.bartleby.com/61/