Climate Science and the Scientific Method
| Peter Klein |
This article on climate science skeptics is making the rounds, and drawing the expected denouncements in the usual quarters. It actually makes some reasonable, and quite mild, statements, namely that climate science, like astronomy or evolutionary biology, is a different kind of “science” than physics or chemistry or geology or other mundane sciences. In the former fields, the fundamental assumptions and key mechanisms are usually not falsifiable, the data are often fuzzier than usual, and there is frequently a lot of hand-waiving to fill in gaps.
Many climate sceptics worry climate science cannot be dubbed scientific as it is not falsifiable (as in Popper’s demarcation criterion). They claim that while elements of climate science may be testable in the lab, the complexity of interactions and feedback loops, as well as the levels of uncertainty in climate models, are too high to be a useful basis for public policy. The relationship of observations to these models are also a worry for climate sceptics. In particular, the role of climate sensitivity.
As well as their use of models, the quality of observations themselves have been open to criticism; some of which have been attempts to clean up issues deriving from the messiness of data collection in the real world (eg the positioning of weather stations), while others have focused on perceived weaknesses in the proxy methods required to calculate historic temperature data such as cross-sections of polar ice sheets and fossilised tree rings.
Such claims are of variable quality, but what unites them is a conviction that data quality in various branches of climate science are below those required by “real science”.
What strikes me the most about these “big” sciences is the language and tone typically used to communicate the results to the public. Where scientists in mundane fields express their conclusions cautiously, emphasizing that results and conclusions are tentative and always subject to challenge and revision, climate scientists seem to view themselves as Brave Crusaders for Truth, striking down “Deniers” (who must be funded by the oil industry or some other evil group). They shout that we “know” this or that about climate change, what the planet will be like in 5,000 years, etc. You hardly ever hear other scientists talk like this, or act as if skeptics are necessarily prejudiced and irrational.