Blue Marble (Planet Earth), a Creative Commons Attribution (2.0) image from woodleywonderworks’s photostream

The C40 Cities Climate Leadership Group (C40) is a worldwide network of large cities who work locally to reduce carbon emissions, and in doing so, also aim to have a global impact on climate change. While cities only take up about 1% of the earth’s surface, 50% of the global population reside and work there. More to the point, they consume 75% of the world’s energy and produce 80% of its greenhouse gas emissions. Recognizing the importance cities play in climate change, C40 was created in 2005 by then Mayor of London Ken Livingstone. In 2006, C40 formed a partnership with the Cities program of President Clinton’s Climate Initiative (CCI) to forward its goal to reduce carbon emissions and increase energy efficiency in cities around the world. New York City Mayor Michael R. Bloomberg is the current chair of the C40.

Last month, C40 organized the Economic Cooperation and Development Conference in Chicago, IL. During the conference, Bloomberg announce two new global networks to help cities achieve both sustainability and prosperity. The first of these focuses on sustainable infrastructure finance and will be led by Mayor Rahm Emanuel and the City of Chicago. From Bloomberg’s remarks:

With assistance from C40’s staff, this network will help cities learn from one another, and work together in creating, evaluating, and replicating new financing structures for improved mass transit, alternative power generation, and other ‘green’ projects. Having Chicago lead this global network will enable others to learn from what Chicago has already achieved, and also the challenges you’re still working to overcome.


This kind of city-to-city exchange, particularly between cities in economically advanced nations and the rapidly growing cities in developing nations, is something C40 is strongly committed to.

The second network focuses on green growth:

This network, which is being led by the City of Copenhagen and which the staff of C40 will also assist, will focus on the full range of ways cities can work with the private sector to attract investment and create jobs, in ways that also meet our environmental goals.

This morning, I touched on several ways we’re doing that in New York – through our ‘greener, greater’ building laws, and our plans to convert some of our municipal waste to renewable energy. Other cities are also bringing the private sector into partnerships to address such issues, too.

There are currently 58 member cities in the C40. In Pennsylvania, Philadelphia is a member. As the group focuses on the largest cities in the world, Pittsburgh is not a member. However, as we blogged here earlier this month, Pittsburgh has its own Climate Action Plan and Initiative.

You can read all of Mayor Bloomberg’s remarks here.