This alarming program investigates the likelihood of the biggest climate change in more than 10,000 years. Scientist Richard Alley asserts that global warming contributes to record amounts of cold freshwater from glaciers and the Greenland ice sheet being pushed into the North Atlantic, threatening to shut down the Gulf Stream that keeps northern Europe and the U.S. warm and wet. Within a decade, a new ice age could set in, with ice floes off the coast of England, and the River Thames frozen over. The U.S. does not look likely to escape, and the effects may even lead to the destruction of the Amazon jungle. Original BBCW broadcast title: The Big Chill. (50 minutes)