“That’s what leadership means, and it will make a difference.” President Obama spoke to mayors and municipal leaders from around the world who were gathered in Chicago at the North American Climate Summit.

Leaders joined to sign the Chicago Climate Charter and make commitments to address climate change. President Obama called this “a powerful signal to the world.”

Paris Mayor Anne Hidalgo is Chair of C40 Cities Climate Leadership Group and a Board Member of the Global Covenant of Mayors for Climate and Energy. After co-hosting the Climate Summit for Local Leaders in 2015 with Michael Bloomberg, the UN Secretary-General’s Special Envoy for Cities and Climate Change, she was elected as the new Chair of C40 Cities, the leading network of the 91 most important cities in the world committed to addressing climate change.

Austin Mayor Steve Adler took office in January 2015 and has focused on tackling Austin’s mobility and affordability issues. He developed and recently passed the city’s largest transportation bond ever, the Smart Corridor plan. Mayor Adler has been a consistent voice for investing in a clean, sustainable future and for climate action.

Guadalajara Mayor Enrique Alfaro Ramírez has promoted and worked to enact numerous policies and actions to mitigate climate change and its effects during his time in office. Guadalajara is currently in the process of fulfilling the goals of their Local Climate Change Policy and registering their carbon footprint, pledging to reduce CO₂ emissions by 40% by 2030.

Mexico City Mayor Mancera has promoted sustainable development, mobility, revitalization of public spaces, and combating climate change as a priority of government. In 2013 he launched the first Mobility Program of Mexico City, giving priority to pedestrians, cyclists and public transport. In 2014 Mayor Mancera launched Mexico City’s Climate Action Program 2014-2020, which aims to mitigate 10M tons of CO₂Eq and reduce the vulnerability of 5.6 million inhabitants that are exposed to the impacts of climate change in the City.

San Francisco Mayor Lee is among 270 U.S. mayors to commit to the Paris Agreement. Under his leadership, San Francisco exceeded its greenhouse gas emission reduction goal two years ahead of schedule, achieving a 28% reduction from 1990 levels as the city’s population and economic activity continue to rise. Mayor Lee also set a goal to have a 50% renewable electricity supply by 2020, and 100% by 2030, among the most ambitious in the country.

Vancouver Mayor Robertson is a Board member of the Global Covenant of Mayors for Climate and Energy and a national advocate for urban issues, focusing on housing, transit, and the transition to a low-carbon economy based on high-growth sectors like digital media, clean technology, and renewable energy. Under Mayor Robertson’s leadership, Vancouver now has Canada’s fastest growing, greenest, and most resilient economy, proving that going green is good for business.