I congratulate former New York City Mayor Michael Bloomberg on his appointment to serve as the United Nations' first Special Envoy for Cities and Climate Change. He has long been a champion of significant action to cut greenhouse gas emissions in cities and bring about a global clean energy economy, and I know he approaches both goals with the sense of urgency and responsibility that this challenge demands. I can't think of a person better suited for this important new role.
This appointment comes at a pivotal moment in the global effort to address climate change. Every single year of the 21st century -- including 2013 -- ranks among the 15 warmest years on record. Scientific study after scientific study continues to paint a clear picture of what our world will look like if we don't change course. The facts are clear. The world we leave to our children and grandchildren is at stake.
As Mayor Bloomberg knows well, how the world's cities respond to climate change will make all the difference. Cities are incubators of economic growth, innovation, and social change. With roughly 5.2 billion people projected to live in the world's urban communities by 2050, how city leaders develop building codes and electricity requirements, how they design public transportation systems, and how they manage urban land use will largely determine whether or not we can meet this global challenge.
During the 12 years he spent as mayor of the nation's largest city, Bloomberg instituted creative programs that cut greenhouse emissions by nearly 20 percent, and his PlaNYC initiative to combat climate change on the local level has become a model for other American cities, including my hometown of Boston. As Chair of the C40 Climate Leadership Group, he also helped bring together large cities from around the world to pursue a more sustainable path forward.
Mayor Bloomberg has hands-on experience confronting climate change in one of the largest cities in the world, while, at the same time, seizing the many opportunities that sustainable city management creates. I'm looking forward to the UN's 2014 Climate Summit in New York next fall and delighted that Mayor Bloomberg will play such an important role in that event and the UN's effort writ large.