Global CoolingOne of the oldest and most worn out skeptic myths is the claim that scientists can’t make up their minds about global climate… because during the 70’s they were predicting catastrophic global cooling. “How can those scientists be so sure we’re causing global warming,” they demand, “when during the 70’s they were predicting that an ice-age was coming?...” In one form or another, this argument has been uncritically rattling around the Far-Right pinball machine for more than a decade. Apart from the usual industry-funded consultants like Fred Singer and MIT climatologist Richard Lindzen (who given his background, ought to know better!), it has been used by everyone from conservative columnist George Will (here and here for instance) and author Michael Crichton (who alludes to it in his novel State of Fear), to fringe conspiracy theory groups like the John Birch Society. Apart from the embarrassingly obvious question of whether scientific knowledge might have made any advances in over 30 years, a few minutes worth of homework is enough to refute this claim. It originated with a few papers from the 70’s, including a 1975 report by the National Academy of Sciences. These addressed what was then known about the aerosol induced troposphere cooling that had been observed since the 40’s (a well-known, and today well understood phenomenon that ended soon thereafter), and the possibility of future Milankovitch cooling cycles. Milankovitch cycles are climate shifts resulting from gravitational perturbations to the earth’s solar orbit, rotation, or nutation by passing astronomical bodies. They occur over timeframes that vary from a few centuries to tens of millennia averaging a few thousand years per cycle, and have nothing to do with investigations of anthropogenic climate change. These articles discuss some of the history of this myth and the imaginative way it was extracted from the science it claims to be based on.