As speculation swirled over the White House's position on the landmark Paris climate agreement this week, a trio of determined governors had a few messages for the president.

"There's nothing Donald Trump can do in our states to stop us from advancing our policies," said Washington Gov. Jay Inslee.

"We are on track to meet the Paris accord," said California Gov. Jerry Brown. "This is America speaking."

To the chorus, New York Gov. Andrew Cuomo added: "You don't get great going backward."

Accompanied by former Secretary of State John Kerry, who steered the U.S. negotiations on Paris, the governors unveiled a new report on Wednesday from the U.S. Climate Alliance, the group they formed after President Trump announced he would withdraw from the historic climate agreement. (Only two other countries haven't signed the agreement, and Nicaragua media reported this week that their country's president plans to do so. If that happens, it would leave Syria and the U.S. alone in rejecting it if Trump pulls out.)

The U.S. Climate Alliance now represents 14 states and Puerto Rico, with the latest inclusion of North Carolina. Collectively, they are equivalent to the world's third largest economy and account for more than 36 percent of the U.S. population. Each member has agreed to meet the U.S. commitments under the Paris climate deal.

The report's main finding: These states are on track to hit a 24 to 29 percent cut in greenhouse gas emissions below 2005 levels by 2025, roughly in line with the U.S. Paris pledge that Trump has disavowed.

From 2005 to 2015, the states in the alliance had already cut their greenhouse gas emissions by 15 percent, the report said, while their economic output grew 14 percent.

"We have exploded the myth that you can't defeat climate change and grow your economy at the same time," Inslee said. "It's not a coincidence that our economies are doing well. It's a consequence of what we're doing to develop clean energy technology."

Cities, Companies Say: 'We Are Still In'

The alliance is among a swell of coalitions and initiatives that have attempted to circumvent the Trump administration's threatened pullout from Paris and rollbacks on climate-related regulations, including the Obama administration's Clean Power Plan.

Among them are the "We Are Still In" coalition, which includes 2,300 cities, states, corporations and universities that have pledged to uphold the Paris accord, and a parallel effort, organized by Brown and former New York Mayor Michael Bloomberg, called "America's Pledge," that's attempting to calculate the effects of climate action by its members and submit that tally at the United Nation's annual climate conference in Germany this fall.

Individual states, meanwhile, have advanced their own efforts. In July, California lawmakers approved an extension of the state's cap-and-trade program. In August, a coalition of nine Northeastern and Mid-Atlantic states—the Regional Greenhouse Gas Initiative—agreed to cut an additional 30 percent of climate-warming pollution from the region's power plants between 2020 and 2030. (When asked by a reporter Wednesday whether California might consider linking its cap-and-trade program to New York's, Cuomo said, "The devil is in the details." Brown said: "I would very much welcome the state of New York into our cap and trade system.")

Gloomy Projections, but Reason for Hope

The optimism contradicts some recent gloomy projections. Just last week, the U.S. Energy Information Agency issued its latest forecast, which said that global emissions of carbon dioxide would grow 16 percent by 2040 from 2015 levels.

Still, researchers say, there's reason for hope.

On Tuesday, the Natural Resources Defense Council issued a new report that said the U.S. can cut its greenhouse gas emissions 80 percent by 2050 if it moves quickly and aggressively toward renewable energy sources and investments in energy efficiency.

NRDC commissioned the analysis from consulting firm Energy + Environmental Economics to analyze how the U.S. can hit the 80 percent target—the amount the Intergovernmental Panel on Climate Change has said developed countries need to cut in order to keep global temperatures within 2 degrees of preindustrial levels.

"This is not a pipe dream," NRDC president Rhea Suh told reporters Tuesday. "It's a vision that builds on progress we're already making. With or without help from Washington, we'll keep moving forward."

"The key," Suh she said, "is to cut our fossil fuel use at least 70 percent by investing in energy efficiency, shifting to electric cars and trains, getting more clean power from the wind and sun and modernizing our electricity grid."

The NRDC projections rely heavily on energy efficiency and aggressive movement toward renewable energy sources—the same drivers that the governors say are sparking economic growth in their states.

"A lot of this depends on states and cities leading the way," said Amanda Levin, a climate and energy analyst for NRDC.