The consequences of climate change for the world are becoming increasingly well-known, even if the world has been slow to act in response. Cities, in particular, are already facing transformational challenges due to rising sea levels, changing weather patterns, and other results of climate change. Consequently, cities have become early adopters of policies to confront climate impacts, and early organizers of actions to mobilize others to respond to climate risks. But what, exactly, are the best practices that cities around the world have put into place to face these dangers? And what are the limits to what they can accomplish in climate policy?
The answers to these questions are threefold, and lie in the reasons why cities are in the forefront; why they will be forced to stress adapting to a changing climate rather than fixing the problems that caused the planet to heat up; and why networks of cities—rather than states—may hold the key to dealing with climate change.
Why cities are at the forefront. Cities are usually the first to confront climate change because, quite simply, they are anchored in one place. Unlike individuals, companies, or even nations, cities are geographically constrained; this fact drives innovation (and presents challenges) in responding to climate change in both the short and in the long-term.
In contrast, individuals are highly mobile—especially so in the United States. Each year roughly 40 million Americans (about 14 percent of the population) move at least once. They move for employment, for education, for family. They do this within a nation that has shown a remarkable capacity to reorganize within its boundaries. Since World War II, the massive shift of population and industry growth in the Sun Belt created a region more important to the national economy than the northeast.
This factor highlights the situation faced by urban areas: Cities do not have an individual’s flexibility to move towards opportunity and away from threat. Instead, they are necessarily defined by geographically tethered infrastructure and investment. This means that as the effects of climate change take root in our urban areas, cities are forced to be early adopters to cutting edge adaptation strategies. In other words, cities cannot run, but must stand and fight.
There are many examples of this phenomenon, both here and abroad: Post-Katrina New Orleans invested nearly $15 billion fortifying the city with the “Great Wall of New Orleans;” Rotterdam piloted a trio of floating bubble-shaped domes on the city’s waterfront, to illustrate the potential for floating cities in the future; New York City will invest $20 billion in seawalls, dunes, and tidal barriers (nearly the same amount the city incurred in damages and lost economic activity due to Hurricane Sandy) to protect against rising sea level; and Project MOSES in Venice has built operational tidal gates to accommodate the deluge caused by dangerous storm surges.
But let’s not be too hasty in praising their ingenuity and thinking that the problems have been solved: The same frontline vulnerability that drives these cities to be early adopters of innovation also means that as the impacts of climate change accumulate over time, they may be less likely to adapt in place. All that these cities can do is attempt to delay the onset of local climate change effects, not solve the underlying problem of an increasingly overheated planet. They are treating the symptom, not the disease.
(And at the same time, we should note that there will be some urban oases—such as the inland city of Duluth, Minnesota—that are likely to benefit in the coming decades, as the climate changes in ways that improve their relative habitability and climate migration brings population to their doors. A better understanding of which and how many cities fall into these and other categories is a priority for policy makers, both local and global.)
Adaptation yes, mitigation no. Consequently, logic suggests that cities will devote scarce resources to adapting to the rising sea levels and higher temperatures of a changing planet rather than try to stop carbon dioxide emissions—adaption rather than mitigation, if you will. They will do this if for no other reason than that cities capture a higher share of their return on investments in adaptation rather than on investments in mitigation. A seawall, a bioswale, and a tree canopy are adaptation measures that generate highly localized benefits at city-scale. Meanwhile, mitigation measures—such as reducing greenhouse gas emissions—generate highly globalized benefits at the scale of the Earth’s atmosphere. Therefore, cities should prioritize adaptation over mitigation.
And yet, many cities are clearly investing scarce resources in mitigation investments. Why?
There are at least three possible reasons: universal values, fair-share mechanisms, and co-benefits. Let us examine each one of these in turn.
Universal values: There are shared values of responsibility for the planet and for people everywhere to be protected from climate impacts. Residents of cities may express these shared values and demand salient policies from their city government. Leaders themselves may hold these values and implement relevant policies under their control.
Fair-share mechanisms: Cities may be motivated by voluntary agreements, like those of the C40 Cities, which try to deliver on the goals of the Paris agreement even if national leaders can’t (or won’t). If every city does their share, then we achieve a scale that “internalizes” the benefits of a public good, in this case mitigating emissions to reduce everyone’s climate impacts. While not as precisely nor as consistently measured as a Nationally Determined Contribution under the Paris Agreement, these city commitments would operate in a similar way: visible participation, shaming for poor performance, counting up collective progress on mitigation.
Co-benefits: Cities may be motivated by the local health and other benefits that arise from mitigation efforts. If the policy motivation for efforts are sufficiently large local benefits, then emissions reductions may be treated as incidental contributions to the global good. Efforts to limit emissions from coal combustion or soot from vehicles creates synergies like this, reducing asthma and emissions from the same policy instrument.
One caveat, however: These may be powerful motivators but are almost certain to be insufficient to prevent temperature rise beyond the 1.5 degrees Celsius targets set in Paris. City policies are already included as a subset of current policies that are predicted to generate a 3.3 Celsius degree temperature rise by 2100.
Cities transmit their best practices and organize demands for other-party action through networks. In a future where it is all-too-likely that climate action will be insufficient, creating a network of like-minded urban areas may be the key organizing challenge facing cities that want to do something to respond to climate change. But this may be a difficult task.
Beyond the generic policy challenges of mitigation and adaptation, cities face a variety of situation-specific risks from climate change that will generate different paths for different cities. Some cities face an emerging need to retreat and relocate from unmanageable impacts. For Miami, for example, rising sea levels may well be a present danger rather than a more distant future risk, and managing it might involve finding partners who can enable the acquisition of higher, dryer land. Cities have historical experience with this, when they have acquired distant water and energy resources through ownership or license. But what forms will this take in coming decades? What models and facilities will emerge from cities that will be early impactees, adopters, and organizers?
The closest instructive experience here is probably the 500 million rural Chinese who have moved into cities over the past 35 years. Nations have demonstrated a remarkable capacity to reorganize themselves within their boundaries. Cities as a system play a critical role in these reorganizations, but not every individual city survives the process. Can public and private investors stay ahead of these changes as climate change radically reorders the habitability and productivity of every nation’s systems of cities? Can the impacts of these changes on the most vulnerable, be responsibly managed by the public sector and non-governmental organizations?
Cities networks have been framed as powerful contributors to improving the performance of national and global actors. But the very qualities and conditions that make cities valuable contributors—their frontline position as innovators based on tangible interests and assets—make it more likely that cities in the future will form networks that best help them achieve increasingly urgent local challenges from climate change, even if they don’t solve the worldwide, underlying base problem.
This column is by Cornelia Colijn. She is the executive director of the Kleinman Center for Energy Policy. You can follow the Kleinman Center on Twitter @kleinmanenergy. This publication is based on a piece drafted for Perry World House and made possible in part by a grant from the Carnegie Corporation of New York. The views expressed are solely the author’s.