The growing threats from climate change leave the global population no choice: We must decarbonise human activity as soon as possible. That includes changing how we build, travel, generate power, and more to reduce greenhouse gas (GHG) emissions. Achieving such transformative change will require a mix of policy reforms, new technologies and significant capital investments. Under ideal circumstances, cities, national governments, global organisations, and private business owners would seamlessly work together to orchestrate actions that deliver results at the scale and speed the planet needs.

The past year has demonstrated that the U.S. federal government can do its part. While political discord has led to paralysis on climate action for well over a decade, within the previous 12 months, Congress has passed three landmark bills—that together invest hundreds of billions of dollars across a range of advanced research programs, utility-focused incentives, modern manufacturing facilities, consumer-facing rebate programs, and more.

The question now is whether cities are well-positioned to do their part—and the current landscape is discouraging. While many cities have drafted climate action plans that pledge specific GHG emissions reductions, they are struggling to hit their targets. One gap in city climate planning and action is internal, with cities often failing to specify detailed strategies that will advance their goals.

Decarbonizing the built environment is scientifically challenging, and our governance structures only add to the complexity. The enormous geographic scale and variety of infrastructure systems in need of upgrades— from constructing bike lanes to delivering clean electricity—is a multifaceted challenge that traverses the public and private sectors across cities. Different ownership structures, regulatory needs, planning approaches, and funding and financing mechanisms are involved, with no one-size-fits-all solution or even common templates for action. This fragmentation of leadership and responsibilities is a nontrivial component of designing decarbonization strategies at the appropriate scale.

This report attempts to better understand why cities are failing to meet their targets and what can be learned from the planning practices that are working well. By evaluating the most comprehensive decarbonisation plans across 50 of the country’s largest cities, the report judges how well the strategies and actions in these plans prepare cities for meaningful, accountable decarbonisation.