Leaders from across the United States are teaming up to take on President Donald Trump’s decision to pull out of the landmark Paris Agreement, the first global effort to tackle climate change via emissions reductions.

Governors, mayors, businesses, investors, colleges and universities declared yesterday (June 5) they would continue U.S. efforts to reduce carbon emissions in an open letter, amounting to a total of 1,439 signatories: 143 cities, nine states, 1,069 businesses and investors, and 218 colleges and universities. Their coalition, dubbed We Are Still In, has not yet set out specific guidelines on how it plans to accomplish this.

Representatives are from all corners of the country, such as Los Angeles, Minneapolis, Jersey City, Yonkers and Chicago. High-profile business names that have signed on include Lyft, Western Union, L’Oreal and Timberland.

In the letter, signatories write:

In the absence of leadership from Washington, states, cities, colleges and universities, businesses and investors, representing a sizeable percentage of the U.S. economy will pursue ambitious climate goals, working together to take forceful action and to ensure that the U.S. remains a global leader in reducing emissions.

It is imperative that the world know that in the U.S., the actors that will provide the leadership necessary to meet our Paris commitment are found in city halls, state capitals, colleges and universities, investors and businesses. Together, we will remain actively engaged with the international community as part of the global effort to hold warming to well below 2°C and to accelerate the transition to a clean energy economy that will benefit our security, prosperity, and health.

The president withdrew U.S. participation in the Paris Agreement June 1 and faced much criticism—from both the right and the left. This move is the latest effort to solidify U.S. global leadership in regards to climate change. The Climate Mayors, a network of mayors dedicated to fighting climate change through local policies, also adopted the agreement’s goals for their own cities. Many of these mayors, including from Houston and Seattle, also signed this letter.

However, as news site Axios noted in a post published today (June 6), this new coalition of U.S. economy leaders will find it difficult to meet Paris Agreement goals without federal support to push the biggest carbon emitters to slow down their emissions output. This includes the states of Texas and Pennsylvania and fossil fuel companies, all of which have not joined the coalition.

This is despite the fact that most Americans oppose Trump’s decision to withdraw from the international climate agreement. A poll The Washington Post and ABC News released yesterday shows that roughly six out of every 10 Americans don’t support this move. The news outlets interviewed 527 adults to gather data for this survey.

Follow developments on this coalition via Twitter #WeAreStillIn.