Michael Bloomberg, the UN special envoy for cities and climate change, at the C40 Mayors Summit in Mexico City on December 1. Reuters Thirty cities, three states, more than 80 university presidents, and more than 100 companies are part of a growing group intending to uphold the Paris Agreement, the climate-change accord that President Donald Trump on Thursday announced the US would be exiting.

The group is being organized by the billionaire philanthropist Michael Bloomberg.

The coalition plans to submit a plan to the United Nations that commits to greenhouse-gas limits set in the Paris Agreement, according to The New York Times. It is negotiating with the UN to form its own National Determined Contribution — a set of emissions standards for each participating nation under the Paris Agreement — that is accepted alongside the other countries in the accord.

The Paris Agreement, reached in 2015, aims to curb climate change before the global average temperature reaches a point that scientists say would have catastrophic and irreversible effects on the planet.

Bloomberg, the former New York City mayor, now serves as the UN secretary-general's special envoy for cities and climate change. On Friday, Bloomberg Philanthropies, his charitable organization, also pledged to donate approximately $15 million over two years to the UN Framework Convention on Climate Change. Under Trump's budget, the UN stands to lose $2 billion in funding toward climate-change action programs by leaving the Paris Agreement.

"The strong consensus among scientists is that the climate is changing due to pollution from human activity. The timing and magnitude of the changes are harder to pin down, but we cannot stick our heads in the sand and ignore the risks they present, especially when we’re already seeing the effects all around us – whether they’re measured in rising sea levels, or depleting coral reefs, or the number of children with asthma," Bloomberg said in a press release.

"Prevention is the best medicine – and the overwhelming majority of Americans believe we should be taking action on climate change. The U.S. is the world’s second largest contributor of greenhouse gases, so we have a particular responsibility to lead – and it’s in our own interest to do so, because if we don’t, we will pay for it in worse health, lost jobs, and a weaker economy."

Only two countries — Nicaragua and Syria — are not part of the Paris accord. After Trump announced that the US would begin its exit, he called the agreement "a massive redistribution of United States wealth to other countries."

The new coalition says it will do whatever it takes to maintain the US's role in the accord, aiming to reduce national emissions 26% below 2005 levels by 2025.

"Americans will honor and fulfill the Paris Agreement by leading from the bottom up — and there isn't anything Washington can do to stop us," Bloomberg said in a press release.