Paul Krugman — Nobel Laureate economist, #5 on Prospect magazine’s 2015 list of the world’s top “thinkers” — gives us powerful advice about the climate policy debate in his August 12 NYT op-ed (similar to this from a February column).
Here’s how I would approach the issue: by asking how we know that a modeling approach is truly useful. The answer, I’d suggest, is that we look for surprising successful predictions. General relativity got its big boost when light did, in fact, bend as predicted. The theory of a natural rate of unemployment got a big boost when the Phillips curve turned into clockwise spirals, as predicted, during the stagflation of the 1970s.
So has there been anything like that in recent years? …Were there any interesting predictions from … models that were validated by events?
In fact he is discussing his own field, macroeconomics — but this insight has deep roots in the philosophy of science and applies as well to climate science. Predictions are the gold standard for validating theories. In The Structure of Scientific Revolutions
“Probably {scientists’} most deeply held values concern predictions: they should be accurate; quantitative predictions are preferable to qualitative ones; whatever the margin of permissible error, it should be consistently satisfied in a given field; and so on.”
Karl Popper set the bar for validation even higher in Conjectures and Refutations: The Growth of Scientific Knowledge
“Confirmations should count only if they are the result of risky predictions; that is to say, if, unenlightened by the theory in question, we should have expected an event which was incompatible with the theory — an event which would have refuted the theory.”
Krugman, drawing on this tradition, points us to a solution for the deadlock in the ever-more-bitter public policy debate about our response to climate change: look for predictions, then test them.
The great oddity of the climate science debate
“Ad hominem attacks aren’t a final line of defense, they’re argument #1. …It’s about an attitude, the sense that righteousness excuses you from the need for hard thinking and that any questioning of the righteous is treason.” {Paul Krugman.}
Activists consider forecasts of models as like the Word of God. Skeptics mutter about vast conspiracies of climate scientists. Lost in this futile decades-long debate is discussion about the methodological testing necessary to create confidence that the results of climate models provide an adequate basis for public policy decisions that shape the world economy.
The necessary tools are well understood, and routinely applied in other fields. For example drugs are tested by prior review of study proposals, followed by analysis of their results by paid non-affiliated multi-disciplinary teams of experts (neither of which is done in climate science). Best of all are successful predictions, and successful risky predictions (for outcomes contrary to expectations) create strong confidence. These hard-won insights have had little influence on climate science. See these posts for examples…
- Thomas Kuhn tells us what we need to know about climate science.
- Daniel Davies’ insights about predictions can unlock the climate change debate.
- Karl Popper explains how to open the deadlocked climate policy debate.
- Paul Krugman talks about economics. Climate scientists can learn from his insights.
- Milton Friedman’s advice about climate models, & how to win the policy debate.
- We must rely on forecasts by computer models. Are they reliable? (Many citations.)
So the bitter public policy debate rattles on, each side hoping for a brute-force political resolution that crushes the large fraction of the pubic that disagree with them. Perhaps that will happen, and perhaps that will produce a useful outcome. But we can do better.
Scientists could re-run older models with actual emissions, not projections, and comparing their forecasts with observed temperatures. These multi-decade predictions would provide objective, powerful data that might resolve the policy debate — or create a clear majority of public opinion to one side.
- My proposal: Climate scientists can restart the climate change debate – & win.
- Putting this proposal in a wider context of science norms and the climate science literature.
This will not happen without public pressure. As we see in Campaign 2016, our ruling elites prefer to give us a circus — treating us like children to be entertained rather than citizens to be informed. But we can stand up and re-take the reins of America, re-shaping the debates about climate change and other key issues.
For More Information
Please like us on Facebook and follow us on Twitter. For more information see The keys to understanding climate change, My posts about climate change, and all posts about the insights of Paul Krugman.
To learn more about the state of climate change see The Rightful Place of Science: Disasters and Climate Change
