Start local, go global

How can cities help avert climate change and combat air pollution?

Over half the world's population now live in urban areas. Local and regional  government leaders gather this week in the World Summit Climate & Territories in Lyon to formulate concrete commitments and course of action by subnational governments in advance of Paris COP21 Climate Conference. They are leaders for both climate action AND clean air!

Cities, non-state organisations and the private sector all have important roles to play in reducing climate change. City involvement in the Climate and Clean Air Coalition (CCAC), is essential to reduce short-lived climate pollutants (SLCPs) that cause both near-term climate change and air pollution. Reducing these pollutants has multiple benefits for cities – including air quality, public health, food security and energy efficiency – and should be a core component of any city’s climate and sustainable development vision.

For example, air pollution reduction could significantly improve health and quality of life in many cities. Indoor and outdoor air pollution is now the world’s largest single environmental health risk, responsible for an estimated 7 million premature, preventable deaths every year. Only 12% of cities achieve WHO guideline levels for air quality — and many cities suffer from air pollution levels that are double, triple (or even higher) above WHO guideline limits.

54% of the world’s population lives in urban areas, a proportion that is expected to increase to 66% by 2050.

It is not difficult to appreciate the important role cities play in all aspects of SLCP mitigation, from raising public awareness to reducing pollutants from local actors and encouraging broader national action.  A groundswell of city support will be instrumental to local, national and international contributions to COP21. The hope of the CCAC is to include action on short-lived climate pollutants in the Declaration of Cities for COP 21.

At the UN Secretary-General’s Climate Summit in New York last September, the CCAC championed five commitments that cities, non-state organisations and private sector entities can use to scale up actions to mitigate the four key SLCPs: black carbon, methane, tropospheric ozone, and HFCs. Our new Call to Action provides options for cities to apply mitigation approaches as part of their local climate and clean air actions and to join the CCAC’s initiatives.

In general, there is a range of actions cities can take to address short-lived climate pollutants. These include:

  • developing inventories of sources and amounts of key pollutants
  • identifying mitigation measures
  • identifying financing mechanisms to support mitigation measures
  • enacting ordinances or regulations
  • promoting public awareness and voluntary action by citizens and industries
  • refining local procurement policies
  • and encouraging national action. 


More specifically, cities can target individual pollutants at the source.  This is the primary focus of the CCAC’s various initiatives, including on municipal solid waste, heavy-duty diesel vehicles, urban public health and HFCs.  We also have a cross-cutting initiative dedicated to broader topics such as promoting increased financing for SLCP mitigation action.

By working with cities and other non-state partners to raise awareness of these cost-effective measures and their numerous near-term benefits, by continuing to demonstrate the gains that can be made through on-the-ground actions, and by continuing to receive support and contributions from policy makers, advocates and industry leaders the CCAC believes we can cut global warming in the near term and improve the quality of life and livelihoods of millions of people.


CCAC Initiatives and Cities

Landfills are responsible for eleven percent of global methane emissions, and that these emissions are increasing due to urbanization worldwide.  The waste sector is also a significant source of black carbon soot, largely from the open burning of uncollected or unlawfully dumped waste, and from the transport of waste by outdated, heavy-duty vehicles.  The CCAC Municipal Solid Waste Initiative supports cities in a variety of efforts, including city waste assessments, capping and closing of open dumps, capturing and utilising landfill gas and ensuring proper waste handling, and organics management. Over 50 cities in Africa, Asia, Latin America and North Africa and Middle East are part of the CCAC Municipal Solid Waste Initiative network via projects such as city baseline assessments, pre-feasibility studies, city exchange programmes to facilitate peer-to-peer learning, the Knowledge Platform, webinars and workshops.  The initiative hopes to increase this to 1000 cites by 2020.

The CCAC Heavy Duty Diesel Initiative aims to reduce the black carbon soot that’s emitted from diesel vehicles.  This initiative is developing Soot-Free Urban Bus Fleets to accelerate the transition from diesel bus fleets to cleaner technologies in 20 major cities, which are home to a combined 234 million people. By 2030, these actions could prevent more than 3,700 premature deaths and warming emissions equivalent to over 2 million tons of carbon dioxide.

In yet another effort, the CCAC’s Urban Health Initiative is developing a worldwide mapping of city initiatives that focus on climate, SLCPs and air quality. The present ‘scoping phase’ led by the World Health Organization includes outreach and consultation with urban leaders from developed and developing cities around the globe.  Pilot cities will be selected for in-depth work, building on other CCAC initiatives, complementing national and international initiatives to reduce urban air pollution.


The CCAC HFC Initiative works to reduce the use of high-global warming potential HFCs in a variety of applications worldwide.  These efforts show that a phase down of HFCs is not only possible, but presents a truly unique opportunity for fast action at low-cost.  Addressing HFCs also brings to light the large gains available from improvements in energy efficiency.  For example, by coupling a phase down of HFCs with the implementation of energy efficiency standards for domestic appliances, cities can not only reduce HFC and carbon dioxide emissions, but also drive down local energy demand, reducing the need to build new power plants and reducing the likelihood of power outages or brown outs, especially in regions with high ambient temperatures and higher numbers of cooling days. 

Finally, the CCAC Financing of SLCP Mitigation Initiative supports mobilizing financial experts and engaging large players, such as development banks and private sector stakeholders to access finance for mitigation projects. For example, the World Bank Pilot Auction Facility is testing innovative funding mechanisms, initially focused on methane emission reduction, while the CCAC’s Black Carbon Finance Study Group developing finance options to stimulate markets to diffuse low-black carbon cooking technology and accelerate technology transition in the diesel sector through concessional and results-based finance.