Which C40 Cities Are Delivering on Climate Action?
Analysis reveals how global cities are translating climate targets into local policies.
1The C40 Network and Climate Action Framework
Established in 2005, the C40 Cities Climate Leadership Group unites nearly 100 major cities around climate action. The network has evolved from a mayors' forum to a planning system aligned with the Paris Agreement's 1.5°C goal. Through its Climate Action Planning Framework (CAPF), cities develop roadmaps toward 2050 net-zero targets. Initiatives like Deadline 2020 transform these goals into concrete carbon reduction trajectories for urban areas.
2Pioneering Cities Reducing Emissions
C40 analysis shows 27 cities successfully reduced emissions after peaking before 2012. Barcelona, Berlin, Copenhagen, London, Los Angeles, New York, Paris and Stockholm are among them. These cities achieved average annual emission reductions of 2% while maintaining population and economic growth. Though policies vary, energy systems, buildings and transportation emerged as common focus areas across successful municipalities.
3Copenhagen's 80% Reduction Achievement
Copenhagen reduced territorial greenhouse gas emissions by 80% between 2009-2022. Success came from decarbonizing district heating systems, renewable energy investments and bicycle infrastructure expansion. However, the city missed its 2025 carbon neutrality target. Final steps like carbon capture at Amager Bakke waste-to-energy plant require national government support beyond municipal control.
4Oslo's Innovative Climate Budget Model
Oslo stands out with its Klimabudsjett (Climate Budget), integrating climate targets into city budgeting. Municipal departments receive specific emission reduction responsibilities with regular progress tracking. Since 2009, Oslo has cut direct emissions while investing in fossil-free construction machinery and EV infrastructure. Yet challenges remain with large projects like carbon capture at Klemetsrud waste-to-energy plant.
5Tokyo's Building Emissions Regulations
Tokyo pioneered a different approach by regulating emissions from large buildings. Its 2010 Comprehensive Emissions Reduction Program established energy efficiency standards for major commercial buildings, resulting in 30% reduction in building-related emissions. The city complements this with solar energy incentives and green building certification systems to transform its urban landscape.
6Energy System Transformations
Cities like Stockholm and Copenhagen achieved significant reductions by decarbonizing district heating and electricity systems. Stockholm's over 90% carbon-free district heating virtually eliminated coal and natural gas use. These cities transformed energy infrastructure through long-term investments in renewable sources and waste heat recovery systems.
7Building Performance Standards
Most C40 cities implement strict performance standards and retrofit policies to transform building stocks. New York's Local Law 97 imposes emission limits on buildings over 25,000 sqm. London established benchmarking requirements to improve existing buildings' energy efficiency. Such policies have delivered 15-25% reductions in building-related emissions across participating cities.
8Transportation Electrification
Public transit, cycling infrastructure and electric vehicles play crucial roles in reducing urban transport emissions. Oslo achieved over 80% electric vehicle share in new car sales by 2023. Paris plans to ban diesel vehicles by 2030. Cities have increased cycling modal shares to 25-40% through expanded bike lane networks and incentives.
9Local Action's Global Impact
C40 cities account for 25% of global greenhouse gas emissions. Their climate actions create important counterbalance to slow national progress. However, the final 10-20% reductions require national policies and international financing. These cities' successes demonstrate local governments' potential to lead in addressing the climate crisis despite higher-level governance challenges.