As recently as 2008, the Republican candidate for US president, Senator John McCain, had sponsored legislative proposals to use cap and trade to address emissions of carbon dioxide and other greenhouse gases.
到了近一点的2008年，共和党推举参议员约翰·麦凯恩（John McCain）为总统候选人，而他本人也支持美国立法使用设限+交易手段去应对二氧化碳和其他温室气体的排放问题。