Cities lie at the heart of our climate change dilemmas. Half the world's population now lives in cities, a figure set to rise to 80 per cent by 2050. Big concentrations of people make vulnerable targets for climate disasters. These will be not only sudden and dramatic (Hurricane Katrina) but also slow and insidious (Shanghai struggling with salination from rising sea levels).
If towns and cities are on the front line of climate change impacts, they are also central to it causes. Cities, after all, are the ultimate "final consumer" of energy, using an estimated 75 per cent of the world total, in transport, construction, industry, and in the heating, cooling and lighting of buildings. Responsible for 80 per cent of greenhouse gas emissions, urban centres also have enormous ecological "footprints," as they suck up food and resources from their surrounding regions.
Yet in theory, cities should produce many of the solutions we need, both in adapting to the changes and in cutting further emissions. As Nicky Gavron, deputy mayor of London, says, cities have both the motivation and the opportunity to tackle climate change. Learning happens fastest in cities, and city dwellers are more likely to be open to political messages about climate change. Moreover, in the developed world, city dwellers are lower per capita users of energy and bigger users of public transport than suburb or country dwellers.
London, along with Toronto, has set up the C40, a network of 40 global cities which aims to accelerate the climate change learning process between cities. Cities have a good record of learning from each other, larger cities from smaller ones in particular. Congestion charging was tried in places like Trondheim in Norway and Singapore before London adopted it. Pioneers like Portland in Oregon have developed many ideas taken up by others.
Many city governments have ambitions that far outpace the lumbering international negotiations for a successor to the Kyoto protocol. Thus while the US government has yet to embrace the concept of binding greenhouse gas emission reductions targets, the city of New York has adopted a goal of cutting emissions by 20 per cent by 2010, from a 1995 baseline. Melbourne in Australia (another Kyoto refusenik at the federal level) wants to go for zero net emissions by 2020.
Adaptation and mitigation in cities
How are these ambitions to be met? There are two agendas: changing the city environment to deal with changing climate ("adaptation"), and changing the use of energy to reduce emissions ("mitigation").
For many cities, the top adaptation priorities are about heat and localised flooding from heavy rain. By mid-century, hotter summers will be the norm across much of Europe. Big cities will be particularly hot because of the urban "heat island" effect. Buildings, roads and pavements soak up heat during the day and release it slowly at night, making cities appreciably warmer from dusk to dawn. At the peak of the 2003 heatwave, London was 9°C warmer than the surrounding countryside. It is this nighttime heat that is so dangerous, especially for the elderly.
However, even with these measures, more people and businesses will install some form of cooling. In the US, electricity demand peaks not in winter but in summer, as the nation cranks up its air-conditioners. In Britain, the air-conditioning market is growing fast. The challenge is to prevent the need for more cooling feeding back into rising electricity use, thus generating more emissions and more warming.
The other major aspect of city adaptation is dealing with the more intense storms and rainfall that climate change will bring. Towns and cities with ageing sewer infrastructure already experience sewage overflow to rivers, or even into homes, during heavy rainstorms. Many cities are now experimenting with better drainage systems. Coastal cities on hurricane or cyclone coasts face even bigger challenges, and are exploring better flood defences.
When it comes to cutting carbon emissions in cities, the obvious places to start are buildings and transport. Energy use in buildings is a dominant source of emissions in post-industrial cities. Young, expanding cities in the developing world have the opportunity to use the latest low-carbon building technologies to produce "eco-town" suburbs, as long as the resources can be found. This is China's approach with Dontang, near Shanghai, the world's first "carbon-neutral sustainable city," now under construction. Eco-towns have also been embraced in Britain, with Gordon Brown promising ten by 2020 (see this month's interview with Yvette Cooper).
More broadly, planning and construction rules can be used to drive up standards in all new buildings. Barcelona has used a solar ordinance in planning law that requires all new buildings above a certain size to use solar energy for hot water. Many cities—including New York and Berlin—are introducing regulatory standards for sustainable construction that are higher than national or regional levels.
However, for older cities, the vast majority of emissions come from existing buildings; the key task is to "retro-fit" energy-saving measures. Toronto has taken a systematic approach here. Capital is made available to retro-fit city government buildings with energy-efficiency measures in lighting, heating, IT and other areas, and is repaid out of cost savings from reduced energy use. Money paid back into the fund is then loaned out again for new projects. Similar approaches have been widely used in other places, from Phoenix, Arizona to the Scottish executive.
Many cities are also taking action to cut transport emissions, both through getting people on to public transport or bicycles, and through introducing lower carbon fuels into their bus and taxi fleets. Bogotá in Colombia has constructed a bus rapid transit system that saves an estimated 287,000 tonnes of carbon dioxide a year. In Beijing, 90 per cent of public buses and 70 per cent of taxis now run on alternative lower carbon fuels. In Calcutta, motor rickshaws have been converted to compressed natural gas.
Meanwhile, London has pioneered the use of congestion charging in Britain, along with expansion of bus services and better facilities for cyclists. The congestion charge has cut traffic-related carbon dioxide emissions in the central charging zone by 19 per cent.
Some cities have also sought to reduce emissions on the supply side. In Scandinavian cities like Copenhagen and Helsinki, over 90 per cent of buildings get their heat, cooling and electricity from a municipally owned energy company operating a high-efficiency combined heat and power (CHP) plant. Local supply of energy has also been tried in a few British towns. In Woking, the best known of these, the borough council has led an innovative approach that combines CHP, retailing of electricity directly to residents, and subsidies to renewables projects.
Political commitment and powers
Examples such as these can give the impression that urban leaders are ushering in a new era of low-carbon city living that will solve the problems of climate change. The reality is more complex. What actually happens in cities depends on three factors: action by national governments, the commitment of city leadership, and what powers and resources city leaders (at all levels) have at their disposal. There are of course huge variations among all of these.
In many of the world's poorest countries, not only are resources for adaptation and mitigation very scarce, but politics based on patronage at both national and city level leaves city residents with virtually no protection from the impacts of climate change. Most African cities have crumbling infrastructure and an absence of effective planning. At the same time, one legacy of colonial economies is that many of these cities are ports, and will sooner or later have to come to terms with rising sea levels. In Latin America, many slum areas are vulnerable to flash flooding and landslides in hurricanes or tropical storms, such as those in Caracas in 2005.
When city leadership is committed and organised, the key question is about powers and resources. This is where the four "P's" come in: personal leadership; procurement, public enterprise and policy.
The personal leadership element is essential for any action. This is demonstrated not only in global city leaders like Ken Livingstone in London and Michael Bloomberg in New York, but also in a new generation of green mayors in the developing world, like Marcelo Ebrard of Mexico City.
Beyond symbolic actions, such as the solar photovoltaic cells on the roof of London's City Hall, personal commitment matters in driving wider action through city operations. What counts as direct city-controlled operations varies, but usually includes at least transport systems, waste management, and fire and police services. The challenge is to reduce energy use across the board in these services.
This leads to the second "P," procurement. Individual city governments have considerable buying power, but together they have more. This is now starting to happen through a new project for energy-saving measures in public buildings in 16 big cities (including Mumbai, Seoul, Houston and London), set up by the C40 and supported by the Clinton Climate Initiative. The project brings cities together with the four largest energy services companies in the world, which have agreed to lower their prices for energy-saving retro-fits.
This kind of approach gets around a problem for city governments that is particularly pressing in Britain—how to get enough money to do what they want. In the rest of Europe and the US, the local tax base tends to be deeper than in Britain. An alternative might be municipal bonds, a solution British cities turned to in the Victorian period in order to fund a range of environmental infrastructure projects, including streets and sewers. Long-term bond finance is also a logical way to pay for action to mitigate climate change, as future generations will pay for measures that they will benefit from.
While city governments can take action to reduce emissions through direct operations and procurement, these usually make up only a small part of a city's contribution to climate change. For example, emissions produced by public transport in London are less than 5 per cent of the capital's total, most of which come from energy use in homes, offices and industry. This is why the provision of lower carbon energy through public enterprise (the third "P")—municipally owned energy companies—could give city governments much greater influence over total emissions. But while some European cities have made this work, the model does not always travel well. (Municipal energy companies used to be common in Britain, but there are now only a handful, despite there being no legal or financial barriers.)
By far the biggest impact on a city's emissions will come through policies (the fourth "P") that affect the way individuals and businesses use energy. Most city governments have some control over land use, planning, housing and private transport, and some also supply energy and water, as discussed above. Probably the most important of these is policy on planning and housing. These powers can make the difference between new developments resembling compact European cities and the "sprawl" model, where car use is inextricably woven into daily life, typified by US cities like Houston and now also seen on the edges of developing-country cities such as Lima or Bangalore.
Cities have blurred boundaries
Sometimes city governments win a battle for more environmental powers—but the battle can also go the other way, in the name of preventing postcode lotteries. One example in Britain is planning policy on renewables, where some local authorities have moved ahead of national planning frameworks. In 2003, the London borough of Merton introduced a requirement that 10 per cent of all energy use in big developments should come from on-site renewables. However, some fear that the Merton rule may now be under threat as government centralises planning powers relating to climate change.
In many European countries, policies governing energy use in homes, offices and private transport get set at national or even EU level. Decisions on tax incentives for smaller cars and resources for home energy efficiency usually get taken by parliaments, not in the town hall. The fact that local, city and national leaders may often come from different political parties only complicates matters.
Another area where the lines are blurred is in measurement of emissions. It is harder to measure the emissions of a city than those of a power station or aluminium smelter. Most of London's "changes" in emissions since 1990 are really changes in the way electricity is generated—mostly outside the greater London boundaries—not anything going on in the city itself. Then there is the question of how widely to attribute responsibility for emissions to a city. For London, should one include emissions from flights leaving Heathrow? In many cities, such as Mexico City in the 1990s or Beijing more recently, recorded emissions can suddenly drop when industry moves out, without any real cuts. These are not academic questions; they have potential implications for carbon finance. Carbon markets could provide huge sources of funding for projects to reduce city emissions, especially in developing countries. Some cities are already engaged in carbon trading: Oakland and Chicago participate in the voluntary Chicago Climate Exchange market. But any kind of carbon trading or offsetting has to be based on attributable emissions reductions.
City leadership is now an important part of the climate change political landscape. It is complex to achieve significant emissions reductions from energy use in cities, as it depends on how far power and resources are devolved. However, many mayors are aiming to push their national governments towards greater commitment on climate change action at the international level. As city leaders become more organised, and use their own achievements as a platform, this ambition may well be realised.
