Since the late 1980s, rising temperatures and dramatic weather-from heat waves and hurricanes to melting glaciers-have fueled a global political and scientific debate about whether life on earth is imperiled by human-caused global warming. NOVA and F... (more)RONTLINE join forces to examine what climatologists really know about the greenhouse effect. What is the connection between rising levels of carbon dioxide and rising temperatures? And what will the real impact of global warming be? The program examines the enormous difficulty in reducing the levels of greenhouse gases in a highly technological world economy and explores the political struggle between environmentalists and industrialists, between rich and poor countries, to grapple with what promises to be the most perplexing issue of the twenty-first century.