The recent report by the European Environment Agency (EEA) on Urban adaptation to climate change in Europe: Challenges and opportunities for cities together with supportive national and European policies (May 2012) tells how cities can adapt to climate change and survive. The report is based on an analysis of data from 576 cities. Without a common definition within the EU on what constitutes “urban” or “city” or “town,” the report concentrates on cities with more than 100,000 inhabitants, but it argues that the results and analysis are relevant to smaller-sized geo-political areas.
This past month, the EEA also published, as part of its Eye On Earth program, an interactive mapping service that identifies certain factors in European cities that will affect the ability of those cities to adapt to the coming climate changes.
The report on Urban Adaptation covers the key challenges from heat, flooding, and water scarcity and drought. It sets out ways to develop plans to avoid the worst impacts, both at the city level and wider regional level.
With over 70% of populations now living in cities, the focus makes sense. Flooding and natural disasters affecting cities are increasingly intensified and happening more frequently due, at least in part, to climate change. A storm in July killed 79 in Beijing and caused US$1.6 million in damages, while typhoon floods caused mass evacuations in Jingdezhen. All of this is the tip of the iceberg since within 20 years China will go from a population of 665 million urban residents to 1 billion and a new megacity, equivalent to Shanghai or Beijing, will be created every 12 months.
Last year New York escaped the worst of storm surges from Hurricane Irene. If the surge had been one foot higher subway tunnels would have been flooded, roadways along the rivers would have merged with the rivers, sections of the commuter rail system would have been impassable, and the subway tunnels under the Harlem and East Rivers would have been unusable for a month, or longer, with economic losses of about $55 billion.
Cities not only house about 70% of the population of most EU countries, they also serve as critical centers for core socio-economic activity (banking, law, investment, universities) as well as for creative endeavors (music, art, dance). But cities are not islands and what happens in the heartlands can have ripple effects in cities, e.g., overbuilding in countryside and wetlands can cause flooding downstream in cities.
The EEA report offers up the whole range of disasters that are beginning to unfold as a result of climate change, especially from more frequent and more intense extreme weather events: higher temperatures (by 2-5º C in 2100), changing rainfall patterns (drier summers in the Mediterranean, wetter winters in Northern Europe), and sea level rise. As a result, flooding will destroy housing, businesses and critical infrastructure; heat waves will kill more and more people, especially the old (an increasingly larger portion of the population) and the very young; water scarcity will pit city residents against farmers, industry and energy providers.
Heat waves in Europe have killed more people than other natural disasters, including 70,000 excess deaths over four months in 2003, and 55,000 in 2010.
What is there about cities that aggravates the impact from increased heat? Besides the sheer density of population, and crowdedness, the widespread artificial surfaces, instead of grass and trees, increase the risks. The heat island created by these surfaces intensifies the health effects from heat waves. Cities store more heat during the day than greener rural areas, and release that heat during the night, so that the temperature in cities can be 10ºC or higher than adjacent countryside.
With small areas of green spaces, relative to the population, there is nowhere to escape the heat. Air conditioning can alleviate the heat inside buildings, but air conditioners continue to spew out more heat and greenhouse gas (GHG) emissions into the city’s environment. Take a ride on a New York subway and enjoy the air-conditioned subway cars, but watch out for the intense heat on the subway platforms from the cars’ emissions of heat. In addition, middle class families can afford the equipment and energy costs for air conditioning; poor people often cannot.
What can be done to counter these heat attacks? Thick, insulated walls and double-glazed windows can reduce reliance on air conditioning, and energy-efficient air conditioning will help, if the electricity system is de-carbonised. Building codes can require such measures; governments can use proceeds from a carbon tax to help fund such measures.
Certain green infrastructure measures are immeasurable: green roofs and walls reduce the heat inside buildings as well as capture some of the water runoff; extensive planting of shade trees reduces the temperature from heat island effects. Obviously, green open spaces and parks can provide a temporary relief from the heat, not to mention a more beautiful surrounding.
Policies, so-called soft measures, to relieve impacts from heat waves include advisories for citizens to wear hats and drink water (no rocket science or economic burdens here), reduce intake of alcoholic beverages, and watch out for your elderly neighbors, the later measure being of particular interest to those of us who are moving on in age.
While heat kills, floods cost. In 2002 alone, major floods in six EU Member States cost more than US $21 billion.
People congregate in cities along rivers and coasts, in part because of the advantages for transportation of people and goods and using water for producing things. The proximity has always created risks from flooding and climate change is very quickly raising the stakes on those risks with more and heavier flooding and sea rise.
Predictions are that rainfall will increase in northern Europe and decrease in southern Europe. In central Europe, rainfall is expected to rise in winter and decline in summer, a pattern similar to what is anticipated in parts of Ireland.
About 20% of European cities with over 100,000 inhabitants, such as in Netherlands, Greece and Finland, are vulnerable to greater than 40% increased flooding, assuming a one meter rise in rivers. In Ireland, the risk is less with all cities expected to have less than 20% chance of increased flooding, but coastlines in Ireland are expected to have between 4 and 13 days of intense precipitation events.
What can be done to counter these flooding events? Those same artificial surfaces that increase heat effects also prevent heavy rain from infiltrating ground and cause overflows into sewer systems, and flooding. Cities can build large reservoirs or storage ponds to hold wastewater overflow from sewers during heavy rainfalls (so-called grey infrastructure), but better yet are green infrastructure projects, including green roofs and walls and porous pavements, which can relieve some flooding by absorbing rainfall, as well as helping with heat.
While the sources of heat impacts are primarily local, flooding in cities is also affected by regional or river basin conditions requiring regional flood risk management plans and actions. In recognition, the EU has adopted a floods Directive that requires Member States to develop and implement flood risk maps and management plans, including risks from climate change.
Examples of intervention in area outside cities include widening river beds to help protect against flooding, as recently shown in the Netherlands in its “room for rivers” program. Belgium created 1200 hectares (almost 3,000 acres) of natural areas to serve as an overflow to protect the city of Leuven. Interestingly, a water company in Dresden taxes water based on the impervious level of properties.
Some soft or policy initiatives to avoid the worst effects from flooding include mapping flood risks, better severe weather forecasting, early warning systems of severe weather events, restricting buildings in flood plains, and minimizing artificial surfaces. In New York, on Roosevelt Island in the middle of the East River, off Manhattan, a memorial for Franklin Delano Roosevelt is being built 15 inches higher than required by past practices to protect against anticipated rising waters from climate change.
Water Scarcity and Drought
Having just discussed flooding — too much water — it is ironic to now claim that scarcity of water and drought are problems equal to flooding. Sometimes there is too much water, in certain cities, while at other times in the same places or in other cities, there is not enough water to share (scarcity, usually a long-term problem) or none for anyone (drought, usually a short-term problem).
Why? More people, more consumption, land use changes, and more heat waves are creating the problem; climate changes will compound it. The competition for water resources will increase between the various users: homes, farms, businesses, industries, and companies that supply energy to all of these users.
How bad can it get? By 2008, Cyprus had experienced four consecutive years of low rainfall and drought, and had to ship water from Greece by tankers and cut water supply for homes by thirty percent.
While the artificial surfaces in cities contribute to water running off without being captured, cities contribute to shortages in other ways. For example, in London each person consumes 161 litres of water per day, compared to a EU-wide average consumption of 150 litres, and 4/5ths of all households in London have no water meters and pay a flat rate regardless of usage. At the same time, about 25% of the water from the out-of-date delivery systems leaks out.
Dublin will soon run short of water and is planning on tapping into the Shannon river basin for water.
What to do? There is no need for rocket science here. What is needed is capital investment by governments to upgrade water delivery systems, and install water meters and charge each user according to usage. Besides the green infrastructure measures mentioned earlier to preserve water resources for use, rainwater harvesting can conserve water for non-drinking uses.
Certain governmental policies can also help with water shortages, such as mapping of vulnerable areas, plus spatial planning that imposes restrictions on building in certain areas, and water pricing as we have mentioned.
As is often the case, when one is trying to understand how to deal with risks from water, it is instructive to turn to the Netherlands. Out of necessity, low-lying Netherlands has always been thoughtful and resourceful about reclaiming land from water. But over 10 years ago it assessed whether what it was doing was still smart in light of coming climate changes and the need to maintain a sustainable environment. It decided it needed to change course. Instead of removing or reducing water-covering spaces, to get more land, it was time to give up land to water. So it is lowering and widening flood plains and constructing water retention and storage areas. It is also building houses on platoons on the water.
What Can Be Done on a Wider Scale
Cities need extensive planning to prevent construction in risk-prone areas, and what constitutes a risk-prone area needs to take into account the best estimates of short-term and long-term effects from climate change. Since these estimates carry huge costs with them and there is much uncertainty in the estimates, this may be the greatest challenge. If we underestimate, destruction and more deaths will follow; if we overestimate, the city’s wealth will suffer. Loss of life or money – some choice.
Determining the risks from long-term climate changes is challenging but manageable. In assessing the needs to protect London, the Thames Estuary 2100 Project took a “real options” approach and estimated the need for flood defenses over a 100-year period and created options that will depend on the different sea level rises at various stages.
Much of the adaptation required from cities will be place-based as local conditions determine vulnerability and adaptive capacity. But regional action is also necessary to address water supply issues and national action is needed to provide the legal and regulatory and pricing policies, and likely some funding for infrastructure projects. Dublin’s tapping into the Shannon will involve local, regional and national stakeholders.
Finally, EU action is needed to address cross-border issues and to urge, or press, Member States to follow the relevant Directives. In Ireland’s case it sometimes is not enough to press, only litigation seems to work.
European Environment Agency, Urban adaptation to climate change in Europe: Challenges and opportunities for cities together with supportive national and European policies, Report 2/2012 (May 2012) www.eea.europa.eu/highlights/publications/urban-adaptation-to-climate-change
EEA, “How vulnerable could your city be to climate impacts?” (04 Sept 2012) www.eea.europa.eu/highlights/how-vulnerable-is-your-city
Olivia Boyd, “Sinking Shanghai ‘not prepared to admit’ climate change threat,” China Dialogue (05 Sept 2012) in News section of irish environment.
Mireya Navarro, “New York Is Lagging as Seas and Risks Rise, Critics Warn,” New York Times (11 Sept 2012), in News section of irish environment.
“Rainwater Harvesting,” in iePEDIA section of irish environment magazine.