It seems that I shocked a few people over in Brussels with my opinions about global warming. Since in large measure I was being deliberately provocative (épater la bourgeoisie!), it would be helpful for me to clarify my stance.
Throughout history, sciences have emerged from the realm of pure speculation. Physics and astronomy from metaphysics, chemistry from alchemy, psychology from philosophical anthropology, etc. A young science is an inexact science, especially when the domain of study is complex. As far as I can see, climatology (and no, I am not a climatologist) is a young science in a complex domain. It is too early for climatology to have gained anything approaching certainty with regard to the nature of the earth's climate.
Yet humans crave certainty. They want a consistent worldview that will explain all the phenomena about which they are so confused. They want such a worldview so strongly that they will sacrifice scientific accuracy and coherence with the facts in order to get it. This is called the will to believe. In young sciences (or young, complex parts of old sciences), the results of succumbing to the will to believe are theories that sound convincing but don't track reality -- Ptolemaic cosmology, Freudian psychology, Marxist economics, superstring theory, nutritionism, and, it seems to me, the global warming theory.
Such theories can be widely believed. They can become scientific -- or, to be precise, pseudo-scientific -- orthodoxies. Just about everyone in a young science can adhere to them (e.g., my father received his training as a psychiatrist during the days of Freudian orthodoxy). So it comes as no surprise to me that, say, nearly every paper published in some peer-reviewed climatology journals would support the global warming theory, just as nearly every paper published in American public health journals might at one point have supported nutritionism, low-fat / high-carb diets, and the like.
Truth is not a matter of counting noses. It is a matter of tracking reality. When the reality is complex, it is harder to track reality. Predictions are not as certain as they will one day become. Models are just that: models. The scientists involved want certainty and may claim more certainty than their young science can yet provide, especially when their grant money depends on supporting the orthodoxy. The journalists clamor for provocative quotes so they can sell more ad space. The public gets progressively more fearful about the future, and they ask their political representatives to do something, anything, to solve the problem. The politicians and bureaucrats are only too happy to oblige, since a good crisis gives them a reason to pontificate and grab more power.
It's not pretty, and it's not science. I realize all too well that people want to know what's happening with the earth's climate. Given that we can't even forecast the weather 3 days from now, I see no reason to be confident that we can forecast what the climate will be like 30 or 50 years from now. The phenomena are too complex, climatology is too young, we don't have enough hard data going back far enough to draw meaningful comparisons, there is too much of which we are simply ignorant (e.g., how clouds form), it's unclear what the relevant factors are, the models involve a great deal of guesswork, the plain fact of political influence looms too large, the ratio of real science to sensationalism and grandstanding is frighteningly low, and the people want to believe in a consistent story even if it is more myth than reality. I'm sorry, but there are just too many mitigating factors here for me to be confident in the forecasts being propagated (I hesitate to call them predictions, let alone results, and I deliberately use the term "propagated" for its connection to the word "propaganda").
So yes I am a skeptic. As far as I can see, science thrives on skepticism and withers in an atmosphere of belief (a word whose root meaning is "to make dear or pleasant"). It is with good reason that we speak of unpleasant truths. Just-so stories about how things might be (but are not) attract those who need a coherent worldview in order to function. But scientists have an ethical and professional responsibility to understand the facts and track reality. Until they do in the field of climatology, I will consider the jury to be out.
If this be heresy, make the most of it.