Developments in science rarely proceed quickly. They go in stages. It varies by discipline, but the underlying process is basically the same. Someone, using their knowledge of a phenomena, suggests a theory and a number of hypothesis that would enable the theory to be tested. Experiments are then conducted which advance the theory – not necessarily “proving” or disproving it, but requiring refinements. As evidence accumulates, the theory either advances or is discarded. Sometimes, a plethora of direct observation (evidence from measurement) suggest a hypothesis which is a part of a theory and this can also lead to advancement.
We refer to this view of science as empiricism (after the Vienna circle) which also requires falsification (after Karl Popper). When Michael Apter, Ken Smith, Sven Svebak and several others (including myself) developed the theory of psychological reversals we had a grand theory of psychology and psychobiology which could be tested empirically by means of a number of different experiments. As each experiment was completed it either confirmed the theory or provided a basis for us having to rethink the theoretical framework, which we did constantly for some twenty five years. We also asked others, especially those who found our theory problematic, to look at the data and to challenge our interpretations both at the level of the data itself (do you get the same result when you analyze these data) and at the level of theory (given this result, can you offer a more comprehensive interpretation than we can?).
Most theorists hope to achieve a paradigm shift (after Khun) as a result of their work. For example, when the proponents of the germ theory of disease finally won widespread acceptance in the early years of the twentieth century, they achieved a paradigm shift in our understanding of disease and changed medical practice. We now know that the germ theory of disease is only partial – new developments in genomics and in the understanding of psychosomatics suggest that there are other basis for “disease”. Equally, the breakthrough in the acceptance of tectonic plates as an explanation of a variety of geological events was also a paradigm shift.
Science, it must be said, is not a democratic pursuit but rather a pursuit for truth. The term “scientific consensus” is generally a red flag to a scientist - a sign that someone is seeking to control the debate or to close an argument. For example, when Einstein proposed his E = MC2 few accepted it as anything more than a hypothesis. When told that some 200 eminint physicists objected to this formulation, Einstein suggested that it took only one “with proof” to make clear that he was wrong. Science, unlike politics, is not a numbers game. Over time, some basic ideas become accepted as cornerstones of science, such as the Laws of Thermodynamics. Such things are rare. Even then, we do not talk of “consensus”, but of generally accepted principles (meaning that there are exceptions and some still wish to argue the Laws themselves).
Recently, following Paul Feyerabend, there has emerged an approach to science which suggest that the boundary between science as a form of logical reasoning based on evidence and polemics needs to be blurred, since what matters in scientific understanding in the service of social aims. Using a variety of examples, he suggests that they have in common the fact that all common prescriptive rules of science are violated in these cases and that the progress of science itself would have been impeded had it not been for the anarchistic view of science promoted. One of his examples is the Copernican revolution. Feyerabend is a radical and he sanction the introduction of theories that are inconsistent with well-established facts if it leads to an advancement of understanding. Feyerabend also advocated that science should also be subjected to democratic control: not only should the subjects that are investigated by scientists be determined by popular election, scientific assumptions and conclusions should also be supervised by committees of lay people.
I have rehearsed these different view of science for a reason. We are challenged to make sense of the science of climate change, which is in fact a collection of different sciences. We have no theory of climate, just a set of hypothesis with a very strong focus on the following:
1. There is such a thing as the greenhouse effect in which the presence of certain volumes of gasses and water vapour have a forcing impact on the earth’s temperature.
2. CO2 is a primary cause of the greenhouse effect, despite it being a small presence in the atmosphere. This warming will have major implications for life-systems.
3. Even though humans emit only a fraction of the CO2 present in the atmosphere, humans are the primary cause of greenhouse gasses and warming.
4. Anthropomorphic CO2 emissions, being a cause of warming, will have an impact on the ice sheets which in turn will affect sea levels significantly over time.
5. By lowering anthropomorphic CO2 emissions we can impact climate over time, despite the role of other factors such as the sun, water vapour, oceans etc.
More recently, it has been suggested that CO2 emitted into the atmosphere may be present for thousands of years.
All of these are hypothesis. Each of them has been subject to a variety of evidence reviews and the jury is out, despite the political desire to call “consensus” and "time". There is evidence to suggest that the climate is a more complex phenomenon than these basic hypothesis suggest and that there is no rush to judgment needed.
Further, a collection of related hypothesis do not represent a theory. A theory offers a comprehensive understanding of a phenomenon, in this case climate. We do not have a theory of the climate which would pass the basic tests of a theory – logical consistency, consistent with observations, having a grounding in empirical evidence, be economical in the number of assumptions, explain the phenomena, provide a basis for making predictions which can be verified by evidence, be falsifiable and testable, be correctable and be refinable. Several hundred experienced and qualified scientists dispute all or some or some aspects of the hypotheses outlined here.
We do have a set of proxies for such a theory in the form of computer climate change models, but these are generally accepted as incomplete and emerging (accept by those who built them). Climate is clearly complex, dynamic and somewhat chaotic and difficult to model. Extrapolating consequences from such models – models which do not include variables for human adaptability, technological innovation and ingenuity – seems a strange thing to be doing.
Rather than develop a theory, what some climate change scientists have done (and this is the basis of the work of the political UN organization the IPCC) is to develop scenarios. Scenarios are different views of a possible future based upon a combination of facts, opinions, ideas and speculation. They are very helpful to get one thinking about options, but only if all the scenarios are viewed as equally possible.
What we have with climate change “science” is anarchy masked by democracy – a Feyerabend's delight. The IPCC alarmists have, in their own minds, a comprehensive scenario for the future which they seek to use to influence public policy. They use evidence is it appears to them to show that they are right and they seek to deny access to policy makers and public opinion those who take a different view – the “deniers” who, in the words of some, are “traitors” who should have no access to public media. On the other side, there are those who see themselves as climate realists who, looking at the evidence as they see it, see something very different from the alarmists. In Popperian terms, they can readily falsify some of the thinking (especially the idea of a linear equation between man made CO2 emissions and the earth’s temperature) and provide alternative hypothesis.
What we have is a clash of methodology (observations versus models) and ideology (Karl Popper and the Vienna School versus Feyerabend). There will be no reconciliation since the two fundamental different views of science and its purpose appear irreconcilable. But the debate is important, not least in terms of the philosophy of science and the nature of the scientific endeavor.
It is a sad fact that there will be no debate between these differing views of climate change and climate science, since one side has closed the door on science seeing all of the issues as settled or only settle-able by members of their own "team". Even Feyerabend would have loved a debate.