Yes: the science has changed from ambiguous to near-unanimous. As an environmental commentator, I have a long record of opposing alarmism. But based on the data I’m now switching sides regarding global warming, from skeptic to convert…  Many greenhouse uncertainties remain, including whether rising temperatures would necessarily be bad. A warming world might moderate global energy demand: the rise in temperature so far has mostly expressed itself as milder winters, not hotter summers. Warming might open vast areas of Alaska, Canada and Russia to development…  Scientific substantiation of a warming world is not necessarily reason for gloom. Greenhouse gases are an air pollution problem, and all air pollution problems of the past have cost significantly less to fix than critics projected, and the solutions have worked faster than expected.