The essential companion to Al Gore's "An Inconvenient Truth." Not becasue this film is accurate and Gore's isn't; rather the two perspectives on global warming remind us that scientific knowledge in this area is far from complete.
That is why incremental change is generally preferable. It allows us to correct mistakes in our knowledge before those mistakes cause serious harm. Of course, the speed and scope of change should match the imminence of the problem. Here, any negative effects that might be attributed to anthropogenically-caused global warming have been incremental or marginal, thus our response should likewise be incremental. Market responses to global warming such as carbon footprint credits achieve positive results without exposing us to the economic risks incumbent in a wide-spread global warming remediation program like that envisioned by Al Gore, et al.