Making Cities Green, Resilient, and Inclusive in a Changing Climate Thriving
For at least 50 years, the view that human activity has spurred the world’s warming has been supported by scientific evidence, the weight of which is now beyond dispute (Benton 1970; IPCC 2021; Madden and Ramanathan 1980). Globally during this time, the number of people living in cities has almost quadrupled and the Earth’s surface temperature has climbed by nearly 1.2°C above its preindustrial levels. This warming has been associated with an increased frequency of extreme hot, dry, and wet events across cities worldwide. Global sea-level rise has also increased the risk of flooding for many coastal cities.
Because of the prosperity they have helped generate, cities have been an important cause of this climate change (Kahn 2010). At the same time, this prosperity has helped make cities more resilient to climate change–related shocks and stressors. Cities have also become increasingly vocal advocates of climate action; however, in the race between climate change and climate action, climate change retains a commanding lead. Cities in high- and upper-middle-income countries, which account for the bulk of global urban carbon dioxide (CO2) emissions, are not moving quickly enough toward net zero. Similarly, although their current contributions to climate change may be small, cities in lower-income countries are not acting fast enough to moderate their emissions trajectories. These trajectories, if left unchecked, will eventually offset any reductions in global emissions made by cities in higher-income countries. Poorly managed urbanization also contributes to an even larger problem—the more general erosion of natural capital. This erosion takes the form not only of polluted skies but also of contaminated water bodies, destroyed natural habitats, and the loss of both plant and animal species.
In addition to not acting quickly enough to mitigate climate change, cities, especially those in low- and lower-middle-income countries, are also not adapting quickly enough to its challenges. The residents of cities in lower- and even in higher-income countries may see climate change as a secondary concern, especially when pitted against poverty, inequality, and a lack of access to markets and services—problems that for some people and some cities have worsened over time. As illustrated by France’s “yellow vest” protests, important tradeoffs undoubtedly exist between such problems and certain policies that aim to tackle climate change. The good news, however, is that complementary policies can help ease these trade-offs, as can policies that make cities more inclusive while simultaneously helping them become both greener and more resilient to climate change. In this context, how inclusive a city is today is also an important determinant of how well it can cope with the climate change–related shocks and stresses of the future.
To ensure that cities thrive in a world confronted by climate change, policymakers at both national and local levels need to work together to implement bold policies to address the interrelated stresses that arise from climate change and urban growth. These include the stresses arising from the pressure of a city’s population on its supplies of land, housing, and basic services; its stock of infrastructure; and its environment. If not well managed, such stresses can give rise to slums and sprawl, deteriorating levels and quality of basic service provision, streets gridlocked with polluting cars and motorcycles, the excessive conversion of fertile agricultural land to urban uses, choking air pollution, and heightened greenhouse gas (GHG) emissions.
Drawing on a wide variety of data sources, this report combines original empirical analysis with insights from a diverse range of secondary literature to take stock of how green, how resilient, and how inclusive cities are, and to shed light on the interaction of stresses related to urban growth with those related to climate change. To address those interrelated stresses, policymakers need to enlist the use of five broad sets of policy instruments—information, incentives, insurance, integration, and investments—in short, the five I’s. The report provides a compass to help cities tailor the use of these instruments to their own circumstances and problems.