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EnvironmentSupporting Sustainable CitiesAmerican Cities Climate Challenge

American Cities Climate Challenge

As hubs of talent and innovation, American cities are uniquely positioned to take bold action to fight climate change and improve the health, economy, and well-being of their residents. Especially after former President Trump’s decision to withdraw the U.S. from the Paris Agreement, American cities became even more emboldened to take on the challenge of climate change head-on. Launched in 2018, the American Cities Climate Challenge provides powerful resources and support to 25 U.S. mayors as they accelerate climate action, using a holistic approach that focuses on clean buildings and transportation. 

Climate Challenge actions are projected to reduce emissions by 40 million metric tons through 2025 – equivalent to taking 8.5 million cars off the road for one year

Participating cities are scaling and implementing climate solutions to help grow the economy, protect public health, and upgrade city infrastructure to meet the needs of the 21st century. Each winning city received a unique package of support, including additional staff capacity, technical assistance from world class partners, access to intensive peer-to-peer networking and support in launching communications, outreach and education campaigns. In total, actions from the Climate Challenge are projected to reduce emissions by 40 million metric tons through 2025 – the equivalent of taking 8.5 million cars off the road for one year.

Examples of policy initiatives that were facilitated with support from the Climate Challenge include:

  • St. Louis’ Building Energy Performance Standard (BEPS) ordinance requires at least 65 percent of the buildings of a certain property type to improve their energy efficiency, thereby reducing greenhouse gas emissions and boosting job creation and economic development.
  • Portland’s citywide network of street improvements have helped to speed transit service and increase transit ridership.
  • Cincinnati’s WarmUp Cincy program assists tenants who live at or below the poverty line with in-unit energy equipment upgrades and financial help to pay energy bills.

American Cities Climate Challenge by-the-numbers:


  • 20 interventions passed or implemented
  • 170 MW new solar under contract
  • 591M square feet covered by new benchmarking policies
  • 34.5k energy audits completed


  • 28 interventions passed or implemented
  • 858 new electric vehicles purchased
  • 213 miles of bike/pedestrian lanes added/improved
  • 15.6k new mobility vehicles added

Now, as the U.S. federal government springs into action on climate under President Biden, these cities will continue to innovate, test what works, and maintain momentum as federal climate policy expands and evolves.

The Bloomberg American Cities Climate Challenge winning cities are:

  • Albuquerque, NM
  • Atlanta, GA
  • Austin, TX
  • Boston, MA
  • Charlotte, NC
  • Chicago, IL
  • Cincinnati, OH
  • Columbus, OH
  • Denver, CO
  • Honolulu, HI
  • Indianapolis, IN
  • Los Angeles, CA
  • Minneapolis, MN
  • Orlando, FL
  • Philadelphia, PA
  • Pittsburgh, PA
  • Portland, OR
  • Saint Paul, MN
  • San Antonio, TX
  • San Diego, CA
  • San Jose, CA
  • Seattle, WA
  • St. Louis, MO
  • St. Petersburg, FL
  • Washington, DC

Top photo: Mike Bloomberg announces St. Petersburg, FL as a winner in the Bloomberg American Cities Climate Challenge alongside Mayor Rick Kriseman.