Paris-on-seaCalifornia pushes on with plans to reduce greenhouse gas emissions

VOTING to extend California’s cap-and-trade programme an extra decade to 2030 was a tough decision for Devon Mathis, a Republican assemblyman who represents a large swathe of the state’s fertile Central Valley. Though once embraced by Ronald Reagan, George H.W. Bush and George W. Bush, cap-and-trade schemes have come to be seen by Republicans as exemplifying government overreach. On the other hand, agricultural business owners in Mr Mathis’s district flooded him with letters in support of cap-and-trade, which they thought would be better than the state’s alternative plans for reducing CO{-2} emissions. Mr Mathis was so torn about the choice he sought out his pastor to pray about it. On July 17th when the vote was held, he opted to support the extension.

Cap-and-trade programmes work by setting a limit (or cap) on how much CO{-2} individual companies can emit. Businesses that pollute less than the cap can sell (or trade) their excess allowance to those that pollute more. The roots of California’s scheme, which is the world’s third largest after the European Union’s and South Korea’s, go back to 2006, when Assembly Bill 32 (AB 32) was passed. In that measure, legislators committed to cutting California’s greenhouse-gas emissions to 1990 levels by 2020—a reduction of roughly 30%, to 431m metric tonnes of emissions. To meet that goal, the state’s Air Resources Board (ARB) pushed a number of initiatives that included a cap-and-trade programme, which it implemented in early 2013.

Since it is relatively new, distinguishing the impact of California’s cap-and-trade programme from its other initiatives on greenhouse gases is difficult. California also has a Low Carbon Fuel Standard, which requires petroleum producers to reduce the share of CO{-2} in their fuels, and an Advanced Clean Cars Programme, a package of regulations to reduce pollution from cars. The Environmental Defence Fund, a charity, estimated in 2011 that cap-and-trade would account for 20% of the pollution cuts required by AB 32.

Altogether, the state is making progress. State-wide emissions peaked in 2004 and have since declined by 10%. The ARB found that greenhouse-gas emissions fell by 1.5m metric tonnes between 2014 and 2015, which is equivalent to removing 300,000 vehicles from California’s (often congested) roads for a year.

Last year the Democratic-dominated legislature set a more demanding emissions reduction target: 40% below 1990 levels by 2030. Cap-and-trade is seen as the key to reaching that, but before this week’s vote its future was uncertain. Over the past four years the ARB has faced several lawsuits over cap-and-trade. Plaintiffs in the suits argue the system functions as a tax. Since it was not approved by two-thirds of the state legislature—the legal threshold for creating new taxes in California—they claim it is unconstitutional.

California’s state government has so far prevailed in court. But to quash such disputes for good Jerry Brown, California’s governor, needed to convince a supermajority of legislators (two-thirds) to extend cap-and-trade to 2030. In the run up to the vote, Mr Brown gave a typically Brownian speech to a state Senate committee: “What am I? 79? Do I have five years more?” he shouted. “This isn’t for me. I’m gonna be dead. It’s for you and it’s damn real.”

Mr Mathis was one of eight Republican state legislators to support the cap-and-trade extension, giving the measure its two-thirds majority. Such bipartisan collaborations are rare—especially on climate-change, over which the electorate is starkly divided. A survey published by Pew Research Centre in October 2016 suggested that only 18% of conservative Republicans believe climate scientists understand “very well” whether climate change is occurring, compared with 68% of liberal Democrats. While these divisions persist in the Golden State, there is broader support overall for climate policies, says Mark Baldassare, the president of the Public Policy Institute of California, a think-tank. When he polled Californians in July 2016, 81% of adults saw global warming as a “very” or “somewhat” serious threat to the state’s economy and quality of life.