The ‘climate change’ issue is the most interesting encounter between politics and science that I think has ever occurred, and it is still occurring, after nearly thirty years. I’ve little doubt it will be with us for quite a while. Only a prolonged period of lower temperatures will erase the global warming scare, and if that occurs we are likely to have another scare, this time about a return to the Ice Age. Human societies respond to scares, even when their members are well educated. The environmental movement will continue for a long time because one can always point to problems with the environment and, as I have written before, it has something of the characteristics of a religion, where facts don’t really matter.
Does the global scare matter? In material terms, not very much, even if the scare make you cross. The amounts spent on the unproductive side of the scare, in pointless research (not that the researchers saw it so), in employing people to regulate carbon dioxide emissions, and in messaging about it all, are not very large in terms of GDP or even of government expenditure. There are lots of other wasted and empty expenditures that taxpayers have to bear. Western countries are wealthy, and they can and do support a lot of waste. As soon as one pointless expenditure is dealt with, another one will appear.
Where it matters much more is in the devaluation of science that has occurred in consequence of activist scientists’ pushing the scare in defiance of the uncertainty that surrounds virtually all of the thousands and thousands of papers that make up ‘climate science’. The growth of science and the research endeavour over the past half-century has produced a growing unhappiness with the quality of some research, and of the failure of the peer-review system to identify poor work quickly enough. It is not simply climate science that has been involved. There are other complaints about biomedical research and psychology, in particular.
Science is often presented by the media as though there is a universal agreement about whatever the issue is. ‘Science tells us…’, or ‘scientists warn’, or ‘science puts paid to denialism’. Headlines or statements of this kind are common. Science is a way of doing things, not a body of authority. Of course, many people want to believe that science is authoritative, because they feel the need to be told what to do. In the climate-change issue there is, and has been from the beginning, lively debate about many aspects of the issue. They are not broadcast in the media, but occur through publication, conferences and websites.
The debaters don’t form two teams. There are several points of view. Richard Muller, best known for the Berkeley BEST temperature data, has proposed a set of definable positions:
Alarmists. They pay little attention to the details of the science. They are “unconvincibles.” They say the danger is imminent, so scare tactics are both necessary and appropriate, especially to counter the deniers. They implicitly assume that all global warming and human-caused global warming are identical.
Exaggerators. They know the science but exaggerate for the public good. They feel the public doesn’t find an 0.64°C change threatening, so they have to cherry-pick and distort a little—for a good cause.
Warmists. These people stick to the science. They may not know the answer to every complaint of the skeptics, but they have grown to trust the scientists who work on the issues. They are convinced the danger is serious and imminent.
Lukewarmists. They, too, stick to the science. They recognize there is a danger but feel it is uncertain. We should do something, but it can be measured. We have time.
Skeptics. They know the science but are bothered by the exaggerators, and they point to serious flaws in the theory and data analysis. They get annoyed when the warmists ignore their complaints, many of which are valid. This group includes auditors, scientists who carefully check the analysis of others.
Deniers.They pay little attention to the details of the science. They are “unconvincibles.” They consider the alarmists’ proposals dangerous threats to our economy, so exaggerations are both necessary and appropriate to counter them.
Muller thinks of himself as a lukewarmer, as do I, though I would write the text there to say that lukewarmers would do nothing until there was a real measured need.
You will see that there is considerable agreement within some of these groups. Richard Lindzen, perhaps the most celebrated of the sceptical scientists (there are dozens, probably hundreds, of them), has also spoken about the levels of agreement. He thought there were three groups of participants:
1) knowledgeable scientists who largely agree with the findings of the UN Intergovernmental Panel on Climate Change (IPCC) and its five assessment reports (ARs);
2) knowledgeable scientists (such as those in the Non-governmental Panel for Climate Change (NIPCC)) who largely disagree with the findings of the IPCC that burning of fossil fuels may cause dangerous global warming;
and 3) politicians, environmentalists, and the media.
I would want another category which includes me, and other sceptics.
The scientists by no means disagree on everything, says Lindzen. They agree on these positions:
• The climate is always changing.
• CO2 is a greenhouse gas, without which life on earth is not possible, but adding it to the atmosphere should lead to some warming.
• Atmospheric levels of CO2 have been increasing since the end of the Little Ice Age in the 19th century.
• Over the past two centuries, the global mean temperature has increased slightly and irregularly by about one degree Celsius.
• Given the complexity of climate, no accurate predictions about future global mean temperature or its impact can be made.
The last dot-point comes from the IPCC’s AR4 which said straightforwardly that in climate research and modelling we should recognise that we are dealing with a coupled non-linear chaotic system, and therefore that the long-term prediction of future climate states is not possible. The most we can expect to achieve is the prediction of the probability distribution of the system’s future possible states by the generation of ensembles of model solutions. What does that mean? Bigger and bigger computers are needed, but even then accurate predictions are out.
I think that the Muller and Linden distinctions are useful, and what they tell us is that there is not a simple battle between ‘the science’ and ‘the denialists’. It’s all much more complex than that, and it will go on for some time, I think. We have had thirty years of serious expense on the science of it all, without any great advance. Nature will be ultimately be the judge.
Later: There ought to have been a reference to the source of the Muller definitions, and there now is.