If you were ever looking for proof that climate science is based more on consensus than actual experimentation, you need look no further than the IPCC’s recent “Climate Change 2013: The Physical Science Basis” report in which the report’s “Summary for Policymakers” states it is “extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.” Really? Extremely likely? You sure that isn’t just “very likely”? Is climate science based on nothing more than subjective opinions of probability? There is no possible way to isolate this one variable (human actions) from the ocean of factors that may influence global temperatures and state with near absolutely certainty that this one variable is not just a cause, but the dominant cause. Unless of course they have a time machine stashed away we don’t know about in which to explore the outcome of alternate timelines. Popular opinion is an illegitimate means to finding truth. The pronouncements of scientists are not endowed with scientific certainty by virtue of them having been made by a scientist. Truth is determined by the evidence, not by the credentials of the messenger. The scientific method (observation, hypothesis, confirmation, prediction) is the only objective means we have to uncovering truth about the physical world. We must understand what science is and is not in order to recognize those who would claim to stand for science but in fact have adulterated the method in order to serve their own interests. Oh, and for those wondering where I get off discussing the scientific method, I have a Ph.D. in organic chemistry – so I know a little something about the scientific method.
Popular opinion is an illegitimate means to finding truth.
It is one thing to make observations and conclude the earth is warming, however it is quite another to leap from that observation and conclude there is one and only one possible cause. It is the height of cognitive dissonance to accept that local weather patterns are far too chaotic to predict beyond a few days but that global long term weather is a vastly simpler system, so simple in fact that we can say with high confidence it is a function of only one variable: carbon dioxide. We can’t predict next month’s weather, but somehow we can say that in one hundred years the temperature will be X. Properly conducted climate science could only be done if we held godlike powers over all activity on the planet (in the same way the chemist can control the conditions of his experiments in the lab). Obviously we do not posses godlike powers. So to get around this lack of omniscience we build an environment in which we can be omniscient: the computer model. But models are imperfect; they rely on both empirical evidence and assumptions. Computer models work well over very short time spans but are inherently flawed at making long-term predictions. The difficulty arises out of the attempt to predict unpredictable quantum level events. Just as we can make reasonable short term predictions about what the traffic around us will do we will utterly fail to predict what that same traffic will be doing 30 minutes later.
And then there is the problem of the unknown unknowns that plague even simple models. For example, if one knew nothing about humans and tried to build growth models based on the first five years of life one would predict that by age 20 humans should be 20 feet tall and weigh 400 lbs. Climate models are now bearing this truth out. In the journal “Nature Climate Change” (that wellhead of conspiracy nuts) a study was published that showed during the last 20 years observed warming was half of what the models predicted and only one quarter of what those same models predicted over the last 15 years. The power of science is prediction, but when the predictions do not pan out one must reevaluate their hypothesis.
Even those demanding “something be done” about climate change should call for a reevaluation of what we think we know. It would be quite disastrous indeed if we made drastic changes in society that resulted in the deaths of billions (due to higher energy costs resulting in decreased food output) only to find out that while global warming is indeed real – it turns out humans have actually played little to no role. We could waste decades prescribing aspirin for the patient’s headache while remaining blissfully ignorant of the brain tumor.