After President Trump pulled the United States out of the Paris climate agreement during his first term, many Democratic-led states passed their own laws to curtail carbon emissions. But most states that set goals for 2030 are not on track to meet them. Now, with voters worried about inflation, and with the war in Iran raising energy prices, some states have begun to cut back or abandon those goals instead.

New York’s plan, like those in other states, was to meet the target by passing a series of individual climate regulations affecting transportation, home heating, industry and utilities. The law allowed citizens to sue if regulations to meet emissions targets were not enforced. With the state behind on its goal, it had a choice: drastically push forward on its emissions target, or abandon it.

In May, New York scrapped the state’s 2030 emissions target. Gov. Kathy Hochul, a Democrat, said sticking to the plan would have imposed “additional crushing costs” on New Yorkers.

New York is not alone in falling behind its goals. Almost every state that passed an economywide emissions target for 2030 is behind pace. Most states need to decrease emissions 4 to 6 percent per year to hit their 2030 goals.

But in the late 2010s and early 2020s — around the time when states were setting their targets — emissions in many such states were falling by only 1 to 2 percent, or in some cases rising. (The latest data we have for most states goes through 2023.)With energy prices increasing and emissions targets seemingly out of reach, other states have begun loosening their goals as well as the policies designed to hit those targets. This year, California’s main climate regulator effectively reduced the cost of emissions that power plants must pay as part of its “cap-and-invest” program; the regulatory board said it was responding to affordability concerns. Connecticut, Arizona and North Carolina have relaxed or removed goals for renewable energy and emissions generated while producing electricity.

The Trump administration has made it harder for states to reach these goals. It has removed consumer tax credits for electric vehicle purchases and heat pump installations, canceled federal grants for solar projects, sued states over plans to make polluters pay, halted offshore wind projects, and scaled back funding for E. V. chargers.

But there is another reason these states with ambitious goals are struggling to reach their targets: Most of them had already made a lot of progress. On the whole, they had lower per capita emissions than the U.S. average when they enacted the goals. One major issue: States with goals already have relatively clean electricity generation.

Because cleaning the power sector is one of the simplest ways for states to reduce emissions — they have authority over utilities — this puts them at a disadvantage for future reductions. (These states almost always trade electricity with other states, as well as with Canada and Mexico, but most calculations and targets take into account only the electricity generated in-state.)“The low-hanging fruit is mostly gone in many places,” said Danny Cullenward, an economist at the University of Pennsylvania. “We need to instead be thinking about the deeper and more difficult cuts.”There is still low-hanging fruit in a state like Kentucky, which has no climate goal. It has decreased carbon emissions more than almost any other state in the last decade, in large part because it retired coal-burning power plants while opening new natural gas plants, which are much cheaper to run and emit less carbon dioxide. New York, on the other hand, had phased out almost all coal by the early 2010s.

It already generates a significant amount of its electricity through renewables and nuclear — which means it has fewer levers to pull. Regulators have blocked the construction of new natural gas plants as part of the state’s efforts to hit its 2030 goals, but even if New York replaced all of its natural gas and oil pow...