Modern science has produced profound and accelerating changes in the way we live over the last two centuries. Most of those changes have been for the better: for example, life expectancy has increased dramatically and worldwide hunger has likewise decreased. Yet we live in a time of widespread disbelief in, and attacks on, science. These attacks come both from the right of the political spectrum (e.g., climate change denial) and from the left (e.g. refusal of vaccinations). I explore some of the science under assault, and the motivations and methods of the deniers.



[Correction, by Claude: After the platform, I discovered to my embarrassment that I erred in describing how an ordinary greenhouse works. After letting sunlight in, the glass in a greenhouse eeps the heat from getting out mainly by preventing hot air from escaping. For more efficient greenhouses, special coated glass can also be used to prevent infrared waves from escaping, but this is a minor improvement --- keeping the hot air in is the main mechanism. My description of the greenhouse effect for the Earth as a whole was correct, though. Since gravity keeps our atmosphere from escaping, rising hot air has no effect in cooling the planet as a whole --- it just cools one place at the expense of heating somewhere else. The only way the Earth can cool is by emitting infrared waves into space, and that is where CO2 comes in, by reflecting those waves back down to the surface. Sorry for my mistake. Darn, science is hard!]