Rep. Rick Boucher ( D-Va . ) , who chairs the House subcommittee charged with crafting that chamber 's climate bill , said in an interview that he was unable to produce one because he and Energy and Commerce Committee Chairman John D. Dingell ( D-Mich . ) wanted a bipartisan bill , but the panel 's top Republican , Joe Barton ( Tex . ) , does not believe human activities contribute to global warming .