Bridges vol. 40, July 2014 / Feature Articles
By Owen McAleer and Ricky Passarelli, Environmental Security Program at the Stimson Center
With the release of the newest Intergovernmental Panel on Climate Change (IPCC) and US National Climate assessments, the threats from climate change are in the headlines more than ever. While the broad projections of these reports are bleak, perhaps the most tangible threats are those facing our cities. Recent events such as Hurricane Sandy in the US and flooding in the Balkans have highlighted the devastation that water can cause in thriving urban areas. In this context, water is both an essential resource and a looming threat. The newest reports reveal that extreme weather events will become not only more frequent but also more severe in the coming decades. Cities will have to deal with greater flooding and longer droughts while, at the same time, managing increased service demands from rapid growth. These warnings are particularly disconcerting for intermediate and secondary cities (according to the World Bank, those with fewer than one million people). With limited capacities, and bearing the brunt of population growth, these urban areas will struggle the most to adapt to changing conditions. Luckily, innovative planners in places like New York and Rotterdam are beginning to prepare creatively for future problems. By considering water as a security issue rather than simply an ecological one, cities are moving beyond climate theory and towards proactive policies for an increasingly urbanized world.
According to the new IPCC report, more than half the world’s population now lives in cities, and this trend is increasing. By 2030, another 1.5 billion people will have moved to urban centers. A significant portion of this growth will occur in the 23 existing “megacities” (cities with more than 10 million people), many of which are located along coastlines, ports, and rivers. Predictably, these cities face massive demands for water infrastructure, energy, and food, as their populations reach record numbers. The report also notes that growth is not confined to mega urban centers. Over 60 percent of urban populations are currently located in intermediate and secondary cities. Despite their smaller size, these mid-size cities face similar challenges. Many have been experiencing 10- or 20-fold growth over the past 50 years, including cities in the developing world where 75 percent of new growth is predicted to occur. All of these municipalities, whether large or small, developed or less developed, are likely to face the same hardships: funding shortfalls, infrastructure demand, and, most of all, climate change.
From a security perspective, the overlap of urbanization and climate change poses a serious threat, particularly regarding the issue of water. Security concerns can include the physical and economic impacts of flooding and of drought, which means everything from building damage to diminishing water supplies to disrupted transportation networks. The effects of sea-level rise, while worrisome on a global scale, hold particular danger in this urban context. The new IPCC report estimates an average global sea-level rise of 26-98 cm (10-39 inches) by 2100, significantly higher than was estimated in the last round. This change could overwhelm existing infrastructures and cause serious damage to coastal communities. Scientists also believe that the idea of “stationarity,” meaning that weather patterns fluctuate within a set range of variability, no longer holds true. Recent studies suggest that events such as the “100-year storm,” a weather variable used for designing infrastructure (seawalls, dams, sewers), are increasing in frequency. In the US, for instance, heavy rainstorms that historically occurred every 20 years are expected to happen three to five times as often by 2100. This analysis applies to inland areas as well, including riparian cities already susceptible to frequent flooding.
Not only will this severe weather occur more often, but research shows that the intensity of weather events is changing. Events like the “100-year storm” and the “100-year drought” are predicted to become more extreme in many places over the coming decades. As engineers and city planners try to anticipate the next big flood or water shortage, they will have to deal with a moving baseline, a particularly difficult situation for the long-term investments required by infrastructure. Combined with increased snowmelt, sea-level rise, and weather pattern shifts, the potential for damage will be greater than ever.
New York City may be one of the most visible examples of these new threats. In 2012, Hurricane Sandy caused $19 billion worth of damage across the city and drew international headlines with scenes of flooded subways and neighborhoods underwater. It also prompted an unprecedented effort by the NYC Department of Planning to make sure the city was better protected and could recover more quickly from future events of this type. In the field of urban planning, this concept is known as “resilience” planning. What makes New York particularly innovative, however, is not that it has a resilience plan, but rather the complex considerations built into its efforts. Going beyond broad citywide goals, New York’s plan delves into the neighborhood level, mapping threats to electrical grids, food distribution networks, and evacuation paths using detailed Geographic Information Systems (GIS) data. For each threat identified, the plan identifies a distinct action agency, policy recommendation, and timeline for implementation. For instance, one section of the plan analyzes the city’s healthcare system and how it will be affected by more frequent flooding. After mapping hydrological predictions, the plan identifies hospitals within the 500-year floodplain and calls for specific updates to their construction. It then charges the New York Office of Long-Term Planning and Sustainability to amend appropriate building codes by the end of 2014, with operational compliance by 2030.
Another particular strength of the plan is that it goes beyond primary threats. While thoroughly addressing traditional flood damage, the plan also takes a comprehensive look at secondary impacts. For instance, one section of the plan identifies the potential threats to neighborhood power supplies. With easy-to-read graphics, it charts facilities within the 100-year and 500-year floodplains, their in-city generation capacities, and outage estimates for various storm probabilities. It then calculates the cost-benefit ratios of potential solutions, based on a 2050 sea-level rise model, including everything from sectionalizing power lines to burying them underground! This level of detail was previously unheard of in resilience planning, let alone for a city the size of New York. Now, because of New York’s initiative, such plans have become the worldwide standard for responsible action.
The idea of urban resilience is equally important in Europe, where 75 percent of the population already lives in cities, and 80 percent will do so by 2020. The risks posed to European cities by climate change are also similarly diverse. Water scarcity is greatest in Southern Europe and gradually decreases towards the North. Flooding, on the other hand, is typically associated with the lowlands of Western Europe, but also pops up in the Alps, where small cities clustered in valleys are vulnerable to glacial melt and runoff from mountain rainfall.
While some places are just starting to plan for these conditions, certain parts of Europe have long been home to resilient thinking. The Netherlands, due to its low-lying topography and resulting floods, has a history of preparing for natural disasters. Such conditions have caused the country to innovate and adapt, making it a thought leader on the subject. Its progressive approaches show in the resilience strategy of Rotterdam, the Netherlands’ second largest city. Rotterdam’s flood management system combines traditional hard engineering, such as dikes, with innovative decentralized features, such as “water plazas.” These “plazas” serve as public recreation spaces during dry weather, for example as a playground, picnic area, or grassy sports field, but act as storage basins when it floods. After a storm, they slowly drain through designed outlets to a nearby body of water, preventing inundation from excessive runoff. Rotterdam's urban strategy also considers natural factors: Policies addressing green roof construction and promoting urban farming ensure that the city not only focuses on flood control but also increases its independent capacity to supply food, energy, and water for future emergencies.
So why focus on resilience in Europe and the US, when the majority of urbanization will occur in the developing world? Because older cities — those with existing transportation networks and zoning patterns, such as Vienna, New York, and London — are often the ones in which barriers to new, resilient strategies are greatest. Furthermore, aging infrastructure is also more vulnerable to natural disasters, as was the case in New York City with Hurricane Sandy. Older networks are not designed to handle future storms, and retrofitting those embedded within the existing urban fabric becomes extremely difficult and costly. Trying to modify sewers, subways, and power grids already in use, and surrounded by centuries of development, requires complex approaches that are usually more challenging than building anew.
While the examples of Rotterdam and New York are encouraging, there is still considerable need for increased resilience planning in both Europe and the US. The European Commission recently stated: “In the field of climate adaptation, the European Union has been slow in taking action.” This has particularly been the case in the wake of the Eurozone economic crisis and the resulting austerity measures. European austerity has sharpened the debate over where and how to invest in improving cities. National governments still have a tendency to focus urban investments in capitals, despite the fact that second-tier cities account for 80 percent of Europe’s urban population. The latter fact suggests that European countries should rethink how they distribute funds, and individual cities need to take initiative in new planning efforts.
Conditions in the US are not much better. The American Society of Civil Engineers estimates that over $100 billion in flood protection upgrades is needed throughout the US, while funding for such upgrades is less than $0.5 billion annually. A recent study by the London School of Economics also concluded that American cities “struggle against tougher inequalities, stronger suburbanization, and weaker social supports” than their European counterparts. These findings suggest that America’s push towards resilience needs to be even more concerted. The fallout from the Great Recession, however, is a major obstacle to new investment. Cities such as Cleveland, Miami, and Los Angeles are still recovering from lost revenue streams and are increasingly looking towards urban renewal funding to augment their finances. Resilience, then, should be a core element of federal funding competition, particularly as droughts spread in the West and Atlantic storms move increasingly inland. Tropical Storm Irene, for instance, caused approximately $733 million worth of damage in the inland state of Vermont alone. The event became the single most devastating natural disaster in the state’s history and showed that even areas located away from the coast will face greater threats.
Urban resilience measures do require significant investment, and the price tags of New York and Rotterdam’s strategies are not cheap. But as threats from extreme weather increase, so do the potential gains from resilience-focused efforts. Enhanced planning can avert major rebuilding costs and offer savings, even if no disaster occurs. In New York, studies have shown that new investments will mitigate the impacts of future storms, potentially saving the city $2 billion in repairs and another $2 billion in improved infrastructure efficiency. Resilience can also protect the economic competitiveness of a region. The struggles faced by New Orleans years after Hurricane Katrina highlight the long-term effects that disaster can have on the economy. In a time when the US and Europe are competing with emerging economic powers, resilience may play a major role in providing a stable basis for future growth. City planners and policy makers should view water within this framework. Climate change is no longer a distant theoretical concern, but an economic reality involving trade-offs, cost-benefits, and long-term impacts. As weather patterns shift, cities should recognize that, although water can be a threat, it is also an opportunity for innovation and the necessary driver of a sustainable urban future.
Ricky Passarelli and Owen McAleer are in the Environmental Security Program at the Stimson Center. Their program focuses on mitigating global conflicts that arise over shared water resources, environmental degradation, urbanization, and food security. The Stimson Center is a nonprofit, nonpartisan global security think tank based in Washington D.C.