Reducing Transportation Emissions, Improving Air Quality Recurring Themes at Global Cities Climate Summit
On October 10 and 11, nearly 2,000 global city leaders from the public, private, and civic sectors gathered in Copenhagen, Denmark, for the C40 World Mayors Summit, an annual meeting centered on the theme of advancing ambitious climate action in cities. C40 Cities is a network of 94 global cities – representing over one quarter of the global economy – committed to addressing climate change. The network, a public-private partnership that serves as an example of voluntary, locally-oriented international diplomacy, allows participating cities to share best practices and exchange data with peer cities about greenhouse gas emission reduction strategies.
The Summit session titled “The Road Less Travelled: Greener and Healthier Streets for All,” featured the following panelists:
- Steve Adler, Mayor of Austin, Texas;
- Ahmed Aboutaleb, Mayor of Rotterdam, the Netherlands;
- Helle Lis Søholt, CEO of urban design firm Gehl;
- Luiz Alvaro Salles Aguiar de Menezes, Secretary of International Relations, São Paolo
Recognizing transportation as the largest source of greenhouse gas emissions globally and traffic congestion as a major contributor to local air pollution, panelists spoke about what they saw as the most transformative actions to reverse these trends. Notably, automobile electrification was not listed as a primary goal among any of the panelists. Rather, shifting mode share away from single-occupancy vehicles, addressing land use with better spatial planning and zoning policy reform, and improving pedestrian and bicyclist infrastructure were listed as the most transformative actions to reduce emissions.
In discussing how to achieve these goals, Søholt called for mayors to take responsibility for shifting to integrated decision-making. She pointed to a current lack of coordination or collaboration across city departments, such as parks and transportation departments. In many cases, ownership of city streets and infrastructure is spread across various entities, resulting in different transportation and climate planning goals, and ultimately, challenges in overseeing progress toward those goals. Merging departments under one oversight body can help to streamline decision-making.
Another session, “Breathe Deeply: City Solutions for Clean Air,” highlighted a number of initiatives to reduce transportation emissions in cities, including low emission zones, central business district vehicle restrictions, and free cross-city busses. Two speakers highlighted the need for better street-level emissions data:
- Ninna Hedeager Olsen, Technical and Environmental Mayor of Copenhagen;
- Karin Tuxen-Bettman, Program Manager, Google
Olsen noted that quiet, narrow city streets often have higher air pollution than highways. This can have health consequences for pedestrians and bicyclists, especially those with respiratory conditions like asthma. Mapping urban air pollution patterns by collecting street-level air quality information can help to uncover which streets have higher concentrations of substances like black carbon, nitric oxide, and nitrogen oxide. With this data, Ms. Tuxen-Bettman indicated that local governments can better decide where to improve transit or prioritize placing electric charging stations or switching to electric buses. This data can also be used to bring public health externalities to the public’s attention.
All plenaries and sessions throughout the Summit recognized that much of the action to reduce emissions across all sectors is now occurring at the city level. The lessons shared and the network fostered by the broader C40 initiative can help to scale the solutions being developed and implemented at the local level.