Sometimes the best way forward is to find a way around.

That’s the plan that dozens of American cities are forming in reaction to US President Donald Trump’s announcement Thursday that he would withdraw the US from the Paris Climate Agreement.

Cities including New York, Los Angeles, Atlanta, and Salt Lake City, along with major corporations like Hewlett-Packard and universities like Emory and Brandeis, are planning to submit a proposal to the United Nations to keep the Paris agreement going, according to The New York Times.

The goal of the plan is to meet the greenhouse gas emission targets that the US pledged to meet under President Barack Obama, and currently includes some 30 mayors, three governors, 80-plus university presidents, and more than 100 businesses, according to the report.

Take Action: Tell the US to Stand By Its Commitments to Climate Change

The ad-hoc effort to keep the pledge where Trump has renounced it could be enough to accomplish its goals, according to former New York City Mayor Mike Bloomberg, who is coordinating the effort.

At the same time, the governors of Washington, New York, and California, also announced Thursday that they were going to form the United States Climate Alliance to uphold the Paris agreement, while 68 mayors have pledged to uphold the agreement in their cities, according to ABC News.

The pledge the US made under the Paris agreement was to cut greenhouse gas emissions 26 percent below where they were in 2005 by the year 2025, and it’s already halfway there, according to the Times report.

While regulations created and enforced by the federal government could help get the country the rest of the way there faster, Bloomberg is confident states and cities can do it alone. They can use greater amounts of renewable energy and build green infrastructure and transit systems.

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“While the executive branch of the US government speaks on behalf of our nation in matters of foreign affairs, it does not determine many aspects of whether and how the United States takes action on climate change,” Bloomberg wrote in a letter to UN Secretary General António Guterres.

“We’re going to do everything America would have done if it had stayed committed,” he told the Times.

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The United Nations currently has no way for non-country entities to participate in the Paris Agreement, but the group could submit information for future reports on progress, Christiana Figueres, an official at the UN, told the Times.

And while Trump has not clarified whether the US will pull funding for the agreement, Bloomberg said Thursday that his charity, Bloomberg Philanthropies, offered $14 million over the next two years — the amount the US agreed to pay — to support it if necessary.