A very greatly expanded version of a 120-minute program made for public television, The Weather Machine discusses the possibilities of a new ice age in our lifetime. We are probably at the end of a warm period, since a cooling trend has been noted around the Earth -- in fact, for 95 percent of the past million years, the planet was much colder than we've experienced it. The weather is getting worse; the wind has changed gear. Calder discusses our present climatic oddities in the context of past centuries, points out possible causes for the changes, details the current state of meteorology, reveals new discoveries about the ice ages and outlines the threats for tomorrow. . . . ""Any natural change of climate is far more likely to be for the worse than for the better."" Nor does he believe that man's venal nature will rise above drought, disaster and snowblitz. The pictures are as striking as the text.