We have less than seven years to halve greenhouse gas emissions if we want to limit global warming to 1.5°C, the threshold scientists consider necessary to avoid some of the most dangerous impacts of climate change. In 2022, floods, droughts, and severe heatwaves claimed thousands of lives and affected millions worldwide, offering a glimpse of what to expect if we fail to take climate action. Since cities account for more than 60% of global emissions and are home to more than half of the world's population, changing how we manage the urban environment must be at the center of our efforts to curb the climate crisis.

Without tackling urban challenges, we cannot solve the climate crisis. The central role of cities is undeniable: they account for 75% of energy-related greenhouse gas emissions. Urban choices influence and can drive change across all systems that must be decarbonized and made resilient, from transportation to food and energy production. As the 2018 report by the Intergovernmental Panel on Climate Change showed, cities—with their concentration of people, economic activity, and infrastructure—are among the most powerful levers we have to drive decarbonization and build resilience quickly enough to meet the targets of the Paris Agreement.