The fact that carbon tax proposals have failed to advance in North America suggests that alternatives are more currently more popular. At least cap-and-trade proposals have passed the US House of Representatives, seen the light of day in the US Senate, and been the topic of discussion in various Canadian federal and provincial governments. Most outside of the carbon tax tent (but inside the camp favoring action on climate change) favor cap-and-trade, most of the remainder favor government subsidies (without necessarily using that term), and a few, mostly environmental advocates, still favor the use of command-and-control regulation (also without specifically calling it that). In the United States, some environmental organizations still call for regulation of greenhouse gas emissions through the existing command-and-control-oriented Clean Air Act. Whether emanating from a sincere belief in the efficacy of command-and-control, or from a strategic desire to use command-and-control as leverage for obtaining passage of cap-and-trade legislation, this has become a distinctly minority view.