Monte Heil (Daily Bee, Nov. 25, 2018) contends climate change is “mere speculation” and “only a theory.” To clarify matters, climate change (global warming) is not a theory. It is a fact supported by many thousands of empirical data points from multiple sources. (See “Climate change: How do we know?” at climate.nasa.gov/evidence). In science, a theory is an explanation for why things in nature behave the way they do. It is a well-established, but provisional, explanation that has predictive power and is based on an abundance of independently verifiable data. Theories regarding climate change that meet the aforementioned criteria aren’t guesswork. They provide valuable insight into the processes involved.
Mr. Heil’s claim that meaningful empirical evidence can only be obtained from “laboratory or laboratory-like” tests is incorrect. Scientific theories can be validated through controlled and/or natural experiments, the latter involving observational or field studies. For example, while geologists can’t duplicate actual volcanoes in the laboratory, they can develop valid theories about them by studying them in the real world. Be that as it may, greenhouse gas theory which provides the mechanism for current climate change was actually first established in the laboratory in 1859 by John Tyndall. Since then, numerous controlled studies have further validated the physics involved. (See “Tyndall’s climate message, 150 years on” bit.ly/TyndallsMessage).