CHICAGO (CBS) — With the Trump administration pulling the U.S. out of the Paris climate accord, and scaling back climate change work at the EPA, mayors from around the world were gathering in Chicago on Tuesday to sign a pact to protect the environment.

Mayor Rahm Emanuel was hosting the two-day summit. A total of 52 mayors from 10 nations — including Emanuel — were expected to sign an agreement on finding climate change solutions.

The Chicago Climate Charter follows the same guidelines as the Paris accord – an agreement to reduce greenhouse gas emissions, and accept how human activity is causing global temperatures to rise at unprecedented rates.

Former President Barack Obama was set to address the second day of the summit Tuesday afternoon at the Sheraton Grand Chicago hotel.

Obama, who signed the Paris Agreement in 2015, has continued to be outspoken about protecting the environment since leaving office, criticizing President Donald Trump for withdrawing the U.S. from the Paris climate accord. While the former president has not named his successor in his criticism of that decision, Obama has made it clear the plan to exit the climate agreement will hurt the U.S.

“The nations that remain in the Paris Agreement will be the nations that reap the benefits in jobs and industries created,” Obama said in June. “I believe the United States of America should be at the front of the pack. But even in the absence of American leadership; even as this Administration joins a small handful of nations that reject the future; I’m confident that our states, cities, and businesses will step up and do even more to lead the way, and help protect for future generations the one planet we’ve got.”

Trump has said the Paris climate agreement would reduce global temperatures only a “tiny amount,” would cost the U.S. economy 6.5 million jobs and “close to $3 trillion in lost GDP,” and would allow other major nations like China and India to significantly increase pollution.

Before taking office, Trump also repeatedly called climate change a “hoax.”

Emanuel said, regardless of the Trump administration’s stance on climate change, mayors can take steps in their own cities to fulfill the commitments of the Paris climate accord.

“This is not about symbolism. We’re committed, all of us, to the Paris protocols. These are the Chicago charters that will be very specific plans per city; each plan different, but each city will get on its way to achieving the Paris protocols,” Emanuel said.

The mayors attending the summit said now is the time to take it in their own hands on the local front to bring change.

“We know that climate change is created by human activity. Therefore, climate change can be solved by human action,” Emanuel said.

St. Petersburg Mayor Rick Kriseman said the federal government is not taking the lead on protecting the environment, and neither are many state capitals, so mayors need to take charge.

“It’s really up to us as mayors to be the leaders,” he said.

Dominique Browning, co-founder of Moms Clean Air Force, said protecting the environment also means protecting health.

“All of these things have a severe impact on children’s health. We see it in asthma. We see it in allergies,” she said.

The mayors who have joined the pact will commit to quantifying, tracking, and reporting their cities’ carbon emissions; and customizing their own plans on how to achieve their goals.

In Chicago, Emanuel has set a goal of reducing greenhouse gas emissions by up to 28 percent by 2025, powering all public buildings in Chicago with renewable energy by 2025, and replacing more than 270,000 street lights with LED fixtures by 2021.

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