Washington is just one of a growing number of states poised to introduce or advance new, stricter, or more expansive carbon fees or cap-and-trade programs in upcoming legislative sessions. Collectively, the measures could help to cut U.S. emissions by at least hundreds of millions of tons in the next decade, and provide critical counterpressure on the Trump administration’s efforts to unravel climate efforts like the Paris accords and Clean Power Plan (see “Exiting Paris, Trump Cedes Global Leadership on Climate Change”). Some of these same states and legislators have proposed similar programs before, only to see them fail for lack of legislative or public support. But the White House’s regressive environmental policies, Democratic gains in the November election, and shifting public sentiments have improved “the prospects for actually passing some of these,” says Michael Wara, senior research scholar at the Stanford Woods Institute for the Environment. Among other pending or forthcoming proposals: Many economists, including some prominent conservatives, argue that market-based mechanisms like cap-and-trade or carbon taxes are among the most effective means of lowering greenhouse-gas emissions. Cap-and-trade systems allow companies to bid on a limited number of allowances for generating greenhouse gases, which decrease over time to reduce total emissions. Carbon taxes are direct fees levied on carbon-based products. In both cases, the impact can spill over to consumers in the form of higher prices. But the raised funds are generally funneled back to citizens, invested in climate projects, or spent on other government programs (see “Canada Moves Ahead on Carbon Taxes, Leaving the U.S. Behind”). There are various trade-offs. Cap-and-trade programs create more certainty about the level of emissions cuts that will be achieved over time. Carbon taxes offer greater clarity about the price companies will have to pay, and are generally cheaper and simpler to administer. Regardless of the particular approach, climate and energy observers say it’s encouraging to see so much gathering momentum at the state level, stressing that the measures provide crucial benefits beyond local boundaries. “Without federal leadership, state-level initiatives have become much more important, both for constraining carbon emissions and for discouraging other countries from following President Trump’s lead of exiting the Paris Agreement,” said Robert Stavins, director of the Harvard Environmental Economics Program, in an e-mail. “The state initiatives are most significant as a signal to the rest of the world, because it would be disastrous if China, India, Brazil, and the other emerging economies decided to take on less ambitious commitments, rescind their commitments, or drop out.” That said, it’s still difficult for state measures to add up to the impact of federal policies, particularly since the states pursuing carbon pricing already tend to be among the nation’s lowest emitters. “You’re not tackling the dirtiest states,” says Danny Cullenward, an energy economist and lawyer at Near Zero, an environmental research think tank.
The US state of Washington may introduce a carbon tax after Democrats took control of the State's Senate during recent elections. A number of other states have proposed similar measures, but none have been successfully implemented, owing to a lack of legislative or public support. In Canada, Prime Minister Justin Trudeau has said he will not impose any new taxes on carbon, although his government is considering introducing legislation that would require provinces and territories to do so. The Washington State proposal hasn't been finalised, but proceeds would be likely to be applied to support renewable energy sources and infrastructure.