Reduction of heat-trapping gas

We need reduce heat-trapping gas for earth and us. Some advanced country were obligated reduction of heat-tapping gas on Kyoto Protocol. Japan participate it too.But USA is not participate. USA is the exhaustest heat-trapping gas in the world. USA isn't participate,I think it isn't significant no matter how other country reduce heat-trapping gas. All of the world must partisepate reduce heat-trapping gas.