Here in this country, carbon emissions are generally falling. The EPA reports they dropped 2.2% between 2014 and 2015. More broadly, the nation’s greenhouse gas emissions are roughly 9% below 2005 levels.

Natural gas is doing most of the heavy lifting — replacing coal as the leading form of electricity generation. But pricing carbon has a role too.

Already, California and the Northeastern states have cap-and-trade systems. And Oregon wants to tie in with the one in California, which sets carbon limits and auctions credits to industry. Those companies that are able to exceed the expectations can either bank their allowances for future use or sell them to other businesses that are unable to meet their obligations. As the ceilings come down, overall emissions then fall.

Right now, the efforts to curb carbon are left largely to the cities and states as well as to those businesses that want to be seen as cutting-edge. It will be increasingly difficult for Washington to ignore those efforts, however, especially if Big Oil is stands firmly behind them.