Now more than ever, what happens in cities is shaping our world. Cities are home to the majority of the global population and power the world’s economy. As centers of innovation and progress, they are the key to solving many of the world’s biggest challenges, including climate change. With 70% of the world’s greenhouse gas emissions coming from cities, they also present the greatest opportunities for action.
Mayors around the world are rising to the challenge. They are leveraging their executive powers to protect their cities from more severe storms and weather, and to target some of the biggest sources of greenhouse gas emissions.
From ambitious flood prevention efforts in Dar es Salaam, Tanzania, to new low-carbon bus rapid transit systems in Rio de Janeiro, Brazil, to energy-saving building practices in Melbourne, Australia—cities are leading in the fight against climate change, while improving public health and growing their economies.
Since its launch at the Climate Summit in New York City in September 2014, mayors around the world can sign on to a Compact of Mayors. The compact is an important step forward and gives cities the tools to measure and manage their greenhouse gas emissions in a way similar to nations under the UN’s 1997 Kyoto Protocol.
Cities’ central role was made even clearer by a recent report, which showed that if the world’s cities took bold actions to reduce emissions, their collective impact would be equal to halving global coal use over the next 40 years.
When the world community convenes in Paris in 2015 to create a new climate agreement, cities must be partners in creating a global solution—one that will help avoid the worst impacts of climate change and promote a healthier future.
Our new research, the Special Envoy’s Report to the UN Secretary-General, completed in partnership with C40 Cities Climate Leadership Group and the Stockholm Environment Institute, shows that if all cities took on aggressive new efforts to reduce building, transportation and waste energy use, they could potentially reduce the world’s annual greenhouse gas (GHG) emissions by an additional 3.7 Gigatons (Gt) CO2e by 2030 over what national policies and actions are currently on track to achieve. By 2050, cities could cut annual GHG emissions by 8.0 Gt CO2e over what national policies are currently on track to achieve, the equivalent of cutting annual global coal use by more than half. Cumulatively, cities have the potential to reduce emissions by more than 140 Gt CO2e by 2050.
The first time that cities’ collective GHG impacts have ever been quantified, the Report underscores the importance of including cities’ climate efforts as nations set GHG reduction targets—something nations have rarely done–to prevent the world’s temperature from rising more than 2 degrees Celsius above pre-industrial levels, a ceiling agreed upon in the United Nations’ 2010 Cancun Agreement.
Importantly, the Report identifies actions in each of the sectors where mayors have the greatest control and the most significant opportunities for greenhouse gas reductions. They are the following:
In the end, this Report demonstrates that cities can actually help their nations achieve the more aggressive GHG targets needed to prevent a global temperature rise, as nations set higher commitments in arriving at a new global climate treaty in 2015.
Michael R. Bloomberg is an entrepreneur and philanthropist who served as Mayor of New York City for three terms, from 2002 through 2013. He began his career in 1966 with an entry-level job at Salomon Brothers, an investment firm. After being let go in 1981, he launched a technology startup providing real-time financial data, Bloomberg LP, which grew into a global company that now has 15,500 employees and offices in 73 countries.
As Mayor of New York, Bloomberg’s innovative sustainability plan, PlaNYC, helped reduce the city’s carbon footprint by 19 percent in just six years. After 2012’s Hurricane Sandy, Bloomberg also created the Special Initiative for Rebuilding and Resiliency to repair communities damaged by the storm and to protect the city’s infrastructure from future impacts of climate change.
As a philanthropist, Bloomberg has given away more than $3.3 billion in support of education, public health, government innovation, the arts, and the environment. He serves as board president of the C40 Cities Climate Leadership Group. In 2014, U.N. Secretary-General Ban Ki-moon appointed Bloomberg as his Secretary-General’s Special Envoy for Cities & Climate Change to engage cities and nations in creating more ambitious goals around climate change mitigation and adaptation.