One year ago, on June 1, President Trump dismayed the world by announcing his intention to withdraw the United States from the global Paris climate agreement. He has since shown no inclination to ease up on his efforts to nullify virtually every initiative the Obama administration took to limit greenhouse gases from power plants, cars, trucks, and oil and gas operations. His disappearing act could not have been more ill timed. As a result of rapid economic growth in Asia and lower fuel prices worldwide, global energy-related emissions increased in 2017 after holding steady for three years.
There is, however, a silver lining: the increasing efforts by states and cities to fill the Trump vacuum. No thanks to Mr. Trump, the United States actually bucked the worldwide trend and reduced its emissions in 2017. The 0.5 percent drop in emissions, small but encouraging, was driven partly by market forces — including the switch from coal to natural gas — and partly by sustained efforts by climate-conscious states to deploy renewable energy sources like wind and solar power.
The principal driver of these efforts is the United States Climate Alliance, a coalition of 16 states (plus Puerto Rico) committed to upholding Barack Obama’s Paris pledge to reduce United States greenhouse gas emissions 26 percent to 28 percent below 2005 levels by 2025. According to a study last year by the Rhodium Group, these states, which account for almost half of the nation’s economy, are on track to meet their share of the burden, with estimated reductions in greenhouse gases of between 24 percent and 29 percent by the 2025 target date — not enough to get the entire country where Mr. Obama wanted it to be, but progress nonetheless.