Less than a week after President Donald Trump withdrew the U.S. from the Paris compact on climate change, well over 1000 governors, mayors, and businesses pushed back.

An “open letter to the international community and parties to the Paris Agreement from U.S. state, local, and business leaders” begins, “We, the undersigned mayors, county executives, governors, tribal leaders, college and university leaders, businesses, and investors are joining forces for the first time to declare that we will continue to support climate action to meet the Paris Agreement.”

Chicago Mayor Rahm Emanuel will host his peers Dec. 4-5 at the inaugural North American Climate Summit. Montréal’s newly-elected Mayor, Valérie Plante, is in Chicago for the summit. She leads Projet Montréal, a political party created by environmental activists in 2004. Projet Montréal’s platform advocates sustainable urbanism and development by reducing car traffic, building infrastructure for pedestrians and cyclists, and reversing urban sprawl.

Plante joins us to discuss how political leaders from around the world have joined forces to fill the gap left by the U.S. on addressing climate change.