(Voor Nederlandse versie klik hier)
Scientific conferences and journals provide the stage where scientific debate among scientists is generally held (i.e. not the newspaper or the television or the internet). The proportion of so-called “skeptical” arguments in the scientific venues is very tiny compared to the overwhelming majority of arguments broadly in line with the consensus view that human activity is altering the climate. Don’t scientists debate anything in the field of climate science anymore then? Of course they do. But those debates generally cover very specific topics, the outcome of which will not dramatically change the consensus view, if at all (see e.g. this realclimate post). Any new finding still has to obey the laws of physics, and has to be consistent with the massive body of observations and evidence already available. Observing a bird in the air doesn’t disprove gravity. The statement that “the debate is over” refers to the “debate” whether current climate change is predominantly due to human activity and whether it poses a problem that needs addressing. That “debate” is over indeed, at least in the scientific arena. There are plenty of interesting tidbits left to debate, but they will not likely change the big picture.
Role of the media
The popular media often paint a false picture of the scientific debate by giving the tiny minority viewpoints equal footing as the consensus viewpoints. That’s like discussing creationism as being a scientific theory of equal merit as evolution. Or to have someone make the case that smoking is not bad for your health at all, when smoking laws are being discussed. Perhaps it feels fair to provide those minority viewpoints with an equal sized platform to communicate their viewpoints, but it gives a false picture of the current scientific thinking on the subject. In doing so, the media do a disservice to their audience. And in some cases they even endanger their audience, as in the example about smoking, and also in the case of climate change. “Teaching the controversy” only makes sense when there really is a scientific controversy. Creating a controversy outside of the science arena and then presenting it as a scientific controversy is deceptive. See for a nice review of this “false objectivity of balance” Stephen Schneider’s website.
There are numerous debates and panel discussions organized everywhere about real and apparent controversies. For example, debates between believers in creationism and defenders of the scientific theory of evolution have been common. Debates about climate change also abound. How useful are these debates? They often result in the audience being confused: Many of them have no clue as to who was right or wrong. Many of them will leave the debate with the impression that the science is not settled at all (or they will confuse pseudo-science and real science). This consequence of the debate is often very useful for the defenders of the (scientific) minority view: Uncertainty and doubt about the scientific consensus provides the minority view with more traction.
If the objective of certain “skeptics” is to delay serious mitigation (emission reduction) measures, sowing doubt about the reality of anthropogenic climate change is a very effective strategy. Public debates and so-called “balanced” reporting in the media serve this purpose very well. They have successfully framed the public debate in concepts such as proof and uncertainty. Whereas for a policy basis, the concept of risk is much more useful. For a long time the tobacco industry successfully delayed actions against smoking with the claim that adverse health effects were not proven. That statement may or may not still be true, dependent on your criteria as to what constitutes proof. But the reasoning lost its effect when people started to realize that the probability of there not being any effect was becoming very small with all the information available, and that the health risks were very substantial indeed. We need a similar realization about climate change. Absolute certainty is not required as a basis for action; rational risk assessment is.