The limits of knowledge and the climate change debate

Those who have knowledge don't predict. Those who do predict don't have knowledge. --Lao Tzu Doubt is not a pleasant condition, but certainty is absurd. --Voltaire The question of whether climate change is produced by anthropogenic global warming (henceforth AGW) has triggered an increasingly contentious confrontation over the conduct of science, the question of what constitutes scientific certainty, and the connection between science and policymaking. In a world in which we seek to understand complex, multifaceted phenomena such as climate (and to extract from this knowledge appropriate policy responses) the enduring epistemological question arises: What do we know? Logical inquiry might be expected to help resolve this knowledge problem (Hayek 1945) but is confounded by the assertion that the "science is settled," by condemnation of those who disagree as "deniers," and even by proposals that they be prosecuted as RICO offenders. (1) There is increasing talk on the left-and even among Democratic state attorneys general and the highest levels of the Obama administration--of criminalizing the very effort to rebut the climate change orthodoxy (Gillis and Schwartz 2015, Moran 2016). What could have been a fruitful, albeit perhaps contentious debate over decisionmaking when addressing highly complex phenomena has degenerated into a prolonged contest. While recognizing the problems attending denial of climate change, our purpose here is to elucidate the limitations of the now-dominant view. We ground this view within a Kuhnian framework and suggest the limitations of that framework in understanding the uncertainties of climate change and policies that flow from it. Kuhn (1962) points to an often-repeated process whereby scientific paradigms become locked in and resist challenges to their validity because knowledge production is socially controlled and deeply invested in the political currents of the day. (2) Power relationships and vested interests have frequently played a critical role in determining what acceptable science is or is not. In contemporary parlance there is historical lock-in and path dependence: once there is commitment to a particular body of knowledge that relates to a particular course of action, the costs of change increase over time and even if one wishes to move to a different path, it is difficult to do so. This is not to say that it is impossible for dissenters from the standard accepted approach to get their views expressed in the standard academic journals, but it is clearly more difficult. Moreover, consistent with the concept of path dependency (Greif and Laitin 2004, Arthur 1989), once a scientific paradigm becomes locked in, it becomes increasingly difficult to challenge the status quo in the accepted scientific outlets, at least until challenges to the orthodoxy of the day become so compelling they cannot be ignored. To be sure, sometimes change does take place in a relatively smooth fashion, as when Lavoisier's description of oxygen led to the abandonment of Becher's phlogiston theory of combustion. At other times, where long-held doctrine is at stake, the conflict over new ideas becomes brutal: Galileo was tried by the Inquisition, found guilty, and spent the rest of his life under house arrest. In all cases, time is involved and supporting facts must be provided before a new paradigm gains acceptance. Both Wegener's 1915 theory of continental drift and Milankovitch's 1912 theory of the relationship of climate cycles to earth-sun geometry were dismissed for many decades until new evidence was provided--the Wilson-Morgan-Le Pinchon-McKenzie evidence for plate tectonics that was codified in 1965-67 and the Hays-Imbrie-Schackleton spectral analysis of ice core data that reinforced the idea of orbital forcing in 1976 (Hays, Imbrie, and Shackleton 1976). Emergence of the AGW Paradigm AGW theory is an example of a contemporary Kuhnian lock-in. …