"Global Warming" is the anecdotal moniker for the larger issue of climate change as an observed and projected effect of an increase in atmospheric levels of "greenhouse gasses," primarily carbon dioxide, as a result of human activity.  This is based on empirical atmospheric and climate data, and has gained the approval of a preponderance of scientists involved in climatic and atmospheric studies, and closely related fields.  

As we have seen with other controversial scientific conclusions, a political controversy inevitably follows when the science doesn't fit the narrative that politicians and certain media wish to construct to support their causes.  We have seen this with evolution, over which a meaningful political debate still rages, despite the fact that a meaningful scientific debate ended some time ago.

Although the scientific research regarding so called "global warming" goes back 50+ years, the scientific conclusions and consensus are seen in popular and political culture as relatively new, and thus is questioned in certain political narratives as being untried and untested, and thus untrustworthy.  This logic takes advantage of the inherent uncertainty built into scientific research, in which the even the most well-established theories are constantly challenged and shaped by new findings.

Contemporary American politics lacks the methodology to take on complex issues, particularly of a scientific nature, given the importance in politics to stay on "message" and present apparent solutions in the form of concise and easily parsed "sound bites" to communicate unambiguous ideology.  As such, it has become clear to me that taking our cues on such issues from political leaders and their associated political media talking heads is a serious mistake, and can only result in a misinformed public.