![]() Yet the expectation of a rich debate among scientists about climate change does not reconcile easily with the widely endorsed shibboleth that human activity will warm the globe dramatically and dangerously over the next one hundred years. ![]() Even then, scientists continue to subject such theories to rigorous testing and debate. In other arenas, only after a theory has been empirically verified has the scientific community coalesced around it. We would, therefore, expect this limit on empirical verifiability to birth widely divergent views on the path, causes, and consequences of earth’s future climate. To reach their conclusions, climate scientists have to (a) uncover the (historical) drivers of climate, (b) project the future path of these inputs and others that may arise, and (c) predict how recursive feedback loops interact over multi-decadal time horizons, all without being able to test their hypotheses against reality. Our intuition is that this narrow distribution of opinions yields a knowability to consensus ratio far removed from the perfect ratio of 1. Yet something nags us about this self-congratulatory consensus. So many great minds cannot possibly be wrong, right? To first approximation, around 97% agree that human activity, particularly carbon dioxide emissions, causes global warming. The scope of agreement achieved by the world’s climate scientists is breathtaking. While not always clear why the K/C ratio can become highly skewed, one interpretation is that more than just the search for knowledge is at play. Too high consensus (skewed K/C ratio) inhibits the ability of an idea to evolve towards truth. Government agencies deny funding to ‘sham’ scientists, tenure boards dissuade young researchers from pursuing ‘the wrong’ track, and the establishment quashes ‘heretical’ ideas. At the upper reaches of consensus, there is less updating of views to account for new information-so much so that supporters of the status quo tend to suppress new facts and hypothesis. This occurs because ideas exist not simply at a single temporal point, but rather evolve over the sweep of time. Indeed, in cases of extreme deviations from the perfect ratio, additional support for a concept with such a lopsided K/C ratio increasingly subtracts from its potential veracity. When the ratio deviates too far from the perfect ratio of 1, either from too much consensus or too little, there is a mispricing of knowledge. Topics that are easily knowable (K ~ 1) should have a high degree of consensus (C ~ 1), whereas those that are impossible to verify (K ~ 0) should have a low degree of consensus (C ~ 0). Let us introduce the K/C ratio-the ratio of “knowability,” a broad term loosely encapsulating how possible it is to reduce uncertainty about an idea’s correctness, to “consensus,” a measure of the idea’s popularity and general acceptance. We can use a simple formula to express how an idea’s popularity correlates with its verifiability. On such topics, independent minds can-and should-differ. But as a question becomes more complex and less testable, we would expect an increasing level of disagreement and a lessening of the consensus. The more easily testable and verifiable a theory, the less debate we would expect. Excerpts:Ĭonsensus, in and of itself, is not necessarily a bad thing. Ryan Brumberg and Matthew Brumberg entitled The Paradox of Consensus. In this post I focus on the paradox of the climate consensus, as articulated in a blog post by D. I have criticized the idea of the 97% consensus many times, and I will leave it to others to critique this latest paper. The title ‘Consensus on consensus’ pretty much sums up what the paper is about - they claim that the combined weight of all the climate consensus papers that finds >90% agreement by scientists should convince us that ‘97%’ is robust. The latest nonsensus on consensus from Cook, Oreskes et al. In our view, the fact that so many scientists agree so closely about the earth’s warming is, itself, evidence of a lack of evidence for global warming.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |