BELFAST, Maine — Maine climate scientists and environmental groups say the United States is making a dramatic misstep by abandoning a global pact among nations aimed at reducing carbon emissions that contribute to climate change.

In 2015, 195 countries — all but Nicaragua and Syria — signed the Paris climate accord. Nicaragua didn’t sign because the nation felt the agreement was too weak. President Donald Trump announced Thursday that the U.S. would pull out of the agreement, setting off a firestorm within the scientific community.

“It’s an extremely poor decision that I don’t think is based on very much real information,” Paul Mayewski, director of UMaine’s Climate Change Institute, said Friday.

For example, Trump said during his announcement that the U.S. would lose $3 trillion in GDP because of the agreement, citing a report from National Economic Research Associates Economic Consulting. That report states that could be a worst-case scenario by the year 2040, but includes multiple other possible scenarios with significantly smaller economic impacts.

Trump has expressed his doubts about the existence of climate change for years, and said the accord would hurt the U.S. economy and cost jobs.

Trump stated that the U.S. might be interested in renegotiating the conditions of the accord, but Mayewski said he believes the chances of that happening are “pretty slim because they’ve already seen what the current administration has done to existing environmental regulations and legislation.”

The decision could carry big implications in terms of which nations lead the push to combat global climate change and the U.S., which is the second largest producer of emissions in the world, has lost some credibility in spite of decades as a leader in climate research and pollution and carbon reduction.

“Now we’re passing the high road in this regard to China, in particular, and Europe,” Mayewski said. “We look extremely foolish internationally,” he added.

Mayewski said it would be critical for U.S. climate scientists to redouble efforts to be involved in research and efforts to combat climate change, even if it means doing so without the help of the the White House.

The United States had committed to reduce its emissions by 26 percent to 28 percent from 2005 levels by 2025. The United States, exceeded only by China in greenhouse gas emissions, accounts for more than 15 percent of the worldwide total.

Lisa Pohlmann, executive director of the Natural Resources of Maine, said the decision could have far-reaching impacts for Maine.

“Maine is especially vulnerable to the impacts of climate change, where our environment and economy are so closely linked,” she said in a statement released in the wake of Trump’s announcement. “Rising sea levels will flood our coastal towns, smog from upwind states will make asthma sufferers sick; fast-warming waters in the Gulf of Maine will threaten our commercial fisheries; and warming weather endangers some of Maine’s most iconic economic sectors, like skiing, maple syrup production, and ocean fisheries.”

Follow Nick McCrea on Twitter at @nmccrea213.