I took a 400 level Atmospheric Chemistry class at the UW as an elective to complete my BS in engineering. The curriculum for this course included studying the greenhouse gas effect (trapping of heat in our atmosphere) due to "human" related CH4 and CO2 (methane and carbon dioxide) emissions here on earth. The course was consistent with many programs on the topic like those frequently seen on the Discovery Channel or PBS.

I think most of the debate on the topic centers around the predicable "rate" of this process, not whether or not it is viable in theory.