Progressive commentators often talk as though anyone who doubts global warming is either a “phony” or a “pig”. One study has claimed that 97% of climate scientists agree that human-made carbon emissions are the cause of global warming. Citing this, Cenk Uygur, the host of The Young Turks, accuses the other 3% of “working for Exxon Mobil and the car companies and all the other people that gain from pollution.”
If we were to go down that route, we would also legitimize conservative conspiracy theories to the effect that the mainstream climate scientists work for the government and are using the “hoax” to get money from the government (not to mention green energy companies and wind turbine producers like GE who benefit from this). The strongest environmentalist lobby in the U.S., the Sierra Club, received $50 million in donations from Michael Bloomberg. The situation is completely symmetrical.
Yet the conservative side of this symmetrical situation is often mentioned by left-wing observers as a catastrophe. Big oil and coal industry owners, most notoriously the Koch brothers, are funding a variety of institutions that try to question the role of carbon dioxide in global warming (see, e.g., Rachel Maddow’s report on this). If these institutions are doing genuine research with the aim of proving global warming theory wrong, I would not consider their work a catastrophe – far from it: I would be grateful to the Koch brothers.
I would be grateful to the Koch brothers for the same reasons that I’m grateful to those who took Ignaz Semmelweis seriously. Semmelweis was a Hungarian doctor in the mid-nineteenth century who believed that diseases are transmitted through certain invisible material that could be carried on people’s hands and could be washed off by rinsing. The immediate reaction to Semmelweis’ work from the scientific community ranged from simple dismissal to outrage. What kind of lunatic questions the indisputable truth that diseases are internally caused, usually due to imbalance in the humours?
In medicine, we are typically able to hold all variables fixed except for the one whose effects we are interested in. By tweaking that one factor while everything else stays constant, we can document the effects with relative confidence. We cannot do such controlled experiments with the climate, as we cannot tweak the Earth’s atmosphere to our liking. So whatever uncertainties are associated with medicine (which are plenty) should be associated multiply with climate science. That is why our models of the climate failed to predict the temperatures of the past 10-15 years correctly. Despite dramatic increase in carbon emissions, recent temperatures have been stable. Dynamical theories about how carbon dioxide can trap heat and reconstructions of the Earth’s temperature in the past millennium using indirect methods such as ice core sampling also involve complicated assumptions.
Are you absolutely certain that we are correct about every single theoretical and statistical assumption we have made? Are you certain that we are not repeating what we did with Semmelweis?
If you are, then you have nothing to be afraid of. Those Koch-funded scientists will never be able to prove anything. In fact, it is a good thing that such strong interests are behind them, because once their failure is recognized, your argument comes away far more robust. But if you are not absolutely certain, you should be happy that someone is trying to find our possible mistakes, in case they do exist.
Now, in terms of what we should do in the meanwhile. We should support legislation and directives to reduce greenhouse gasses and phase out fossil fuels as much as possible.
Why would I say this when at the same time I am defending “climate deniers?” First of all, one needs to adopt a consistent attitude towards things on which one is not an expert. Either you decide to defer to experts on these issues, or you adopt some other strategy. If you decide to defer to experts across the board, then you should act as though raising taxes hurts economic growth, vaccines are good for children, and the Earth is getting warmer. In any case, one’s attitude can’t be a simple pick-and-choose strategy that liberals and conservatives use.
Another reason is a cost-benefit analysis. If climate scientists are indeed correct, too much is at stake. We are risking, if not our lives, at least our children’s lives, our planet and much of the natural environment. On the other hand, if climate scientists are incorrect, what will we be giving up? Hardly anything. We will be giving up oil and coal, which are limited resources and will sooner or later run out anyway; which pollute the air with toxins beside greenhouse gasses; and which harm the environment in the process of extraction. There is too much harmless wind and sunlight not to be using.