The governors of California, New York and Washington state -- which represent 10 percent of the country's greenhouse gas emissions -- created the United States Climate Alliance, which at last count had grown to include 12 states and Puerto Rico.
At the city level, 323 mayors formed a similar alliance called Climate Mayors, which is dedicated to bringing down emissions. At the same time, Michael Bloomberg, the former mayor of New York and the current U.N. secretary-general's special envoy for cities and climate change, assembled a group called America's Pledge, made up of mayors, governors, university presidents and companies. Bloomberg told The New York Times that “we’re going to do everything America would have done if it had stayed committed [to the Paris accord].”
It’s an admirable goal, says Mark Muro, a senior fellow for the Brookings Institution's Metropolitan Policy Program who has written extensivelyabout states' role in combatting climate change. "But can states and localities do everything all by themselves? No way."
Michael B. Gerrard, a professor of environmental law at Columbia Law School, agrees.
“Even all the policies under Obama did not add up to enough [to hit emissions targets under the Paris accord]," he says. "Trump’s policies mean we’re going to be even further behind. Strong actions by states and cities can make up some -- though not all -- of the difference.”
With this political landscape in mind, Governing spoke to a host of environmental policy scholars -- including Gerrard and Muro -- to get a sense of what state or local actions could be most effective in combating climate change and which would be most likely to pass, depending on the partisan climate in statehouses and city halls.
Renewable Energy
One of the most effective tools states can use to lower emissions are Renewable Portfolio Standards (RPS), or requirements that a certain amount of energy in the state come from renewable sources like wind and solar. They're particularly powerful because of their bipartisan attraction.“You see surprisingly wide support for these standards, even in really red states -- though there they aren’t described as climate policy,” says Rob Williams, a professor of economics at the University of Maryland and a senior fellow at Resources for the Future. “There are lots of reasons people like renewable energy. Sometimes it’s about energy independence or local environmental issues that don’t have to do with climate.”
Twenty-nine states currently have RPS, including Texas, where the requirements have helped it become the nation's leading producer of wind energy.
From Sidewalks to Skyscrapers
Not every climate change policy, however, is enacted to help the climate, says Muro.“States often control building codes; states control land use management; states shape and add their own investments to transport systems and decide whether investments will flow into urban development or sprawl-inducing freeways,” he says.
All of those decisions, depending on how they're made, can have a negative or positive impact on emissions.
Gerrard agrees: “States and cities control things like the energy efficiency of buildings, which is one of the most important things to focus on.”
California's suite of climate policies in the wake of its landmark 2006 climate bill, A.B. 32, have leaned heavily on regulation of this kind to reduce emissions. In addition to renewable portfolio standards, which have increased the use of renewable energy in the state, California has enacted regulations to reduce tailpipe emissions, contain urban sprawl and reduce the number of miles people drive in cars.
This collection of policies appears to have worked, too.
As of 2014, emissions were down 10 percent from their peak in 2004. According to David Roberts at Vox, regulation has accounted for the majority of the emissions reductions since A.B. 32 was passed.
Carbon Pricing
More hotly debated and politically divisive are programs meant to put a price on polluting. The two main versions of this kind of policy are cap and trade and carbon taxes. While cap and trade has proved to be more politically viable at the state level, both Muro and Williams believe carbon taxes would be more effective at reducing emissions.Simply explained, cap-and-trade programs set an overall cap on carbon emissions in a state. Governments then dole out permits either for free or by auction that allow a company to emit a set amount of carbon dioxide (CO2), which they can trade with one another depending on their emissions needs. Any company that emits CO2 in excess of their permits pays a fine. Each year, the overall cap (and therefore the number of permits) is reduced, which should slowly reduce emissions over time.
There are two large cap-and-trade programs in the U.S. One exists in California, as part of its implementation of A.B. 32, and the other exists in a coalition of Northeastern states: Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New York, Rhode Island and Vermont. The Regional Greenhouse Gas Initiative, as it’s called, works in concert to reduce emissions as well as leakage (the issue of companies simply moving out of state to escape regulation).
In both of the programs, carbon prices have been much lower than originally projected, which means they’re not acting as the kind of deterrent they were supposed to, says Williams. Experts generally agree that cap and trade has likely had little or no effect on emissions reductions in California -- all the progress has been made via regulations and the market's natural progression toward renewables.
Cap and trade is also much more complicated than a carbon tax, which simply makes companies pay to emit carbon and other harmful gases, says Williams. However, carbon taxes are generally perceived as a political impossibility -- there are no state carbon taxes anywhere in the country.
But some experts think that will soon change.
Washington state had a carbon tax on the ballot last year, but Williams says it failed for reasons mostly unrelated to the tax itself. The Carbon Tax Center identifies eight states where the outlook for a carbon tax is promising: Connecticut, Hawaii, Illinois, Maryland, Massachusetts, New York, Washington and the District of Columbia.
Of course, even where these policies have a political chance, they face a fairly significant leakage problem, Williams explains. One of the best ways states can address that is by forming regional alliances, like the Northeast did. But Williams is skeptical of that happening elsewhere.
The Market's Role
The scholars interviewed agreed that, regardless of the country's participation in the Paris accord, progress will likely continue.Market forces will keep moving states away from fossil fuels and toward renewable energy, decreasing emissions in places that aren’t even trying, says Columbia University's Gerrard. There will still be uneven reductions, he says, but at the very least we shouldn’t see active increases in emissions anywhere.
“Many places will realize that the energy savings from efficiency measures are economically sound regardless of how you feel about climate,” he adds, offering Texas and Iowa as examples. Both states have become leaders in wind energy production -- not out of any particular feelings about climate change but out of economic interest.
Williams, however, cautions policymakers to consider more than just the economy.
“Because the politics vary, what’s politically feasible in one location may be different from another," he says. "You have to be flexible about what the policy is and go for what will work politically in any given situation, instead of insisting on the most economically ideal option.”
