Pictures of the Future      Fall 2008

Shrinking our Footprints

^{London plans to cut its greenhouse gas emissions by up to 60 % by 2025. A Siemens-McKinsey study shows how it can meet its objective}

Cities play a crucial role in the fight against climate change. They already account for over half the world’s population, and six out of every ten people on earth will be living in cities by 2025. Cities and their residents are also responsible for approximately 80 % of the greenhouse gases emitted world­wide, a disproportionately large amount. Big cities are very aware of this problem, as a study entitled "Megacity Challenges" showed (see Pictures of the Future, Spring 2007, Megacities – Facts & Forecasts). But when big cities must choose between environmental protection and economic growth, the environment often loses out.

But economic viability and environmental protection don’t have to be at odds. Researchers taking part in the "Sustainable Urban Infrastructure" project, which was carried out with support from Siemens, have for the first time determined the potential and costs of technologies for preventing greenhouse gases in cities. Using London as an example, management consultants McKinsey & Company analyzed more than 200 technological abatement levers that would reduce the city’s CO₂ emissions by almost 44 % by 2025 relative to the 1990 figure of about 45 mill. t, in addition to cutting water consumption and improving waste disposal. Many of the levers they identified also make good sense in economic terms. For example, nearly 70 % of the potential annual savings of almost 20 mill. t of CO₂ identified for London can be achieved with the help of technologies that pay for themselves, largely by reducing energy costs. Over their lifetimes, in other words, they result in no additional costs, but actually help to save money.

Ambitious Aims. The British metropolis has its work cut out for it. By 2025, London intends to reduce its greenhouse gas emissions by 60 % relative to the Kyoto base year of 1990—an ambitious but, as the study shows, feasible objective.

Technologies alone could cut London’s CO₂ emissions by 44 % by 2025 relative to 1990 levels. This would enable it to meet its Kyoto objective (a reduction of 12 % by 2012). For comparison, the EU’s target is a reduction of 20 % by 2020, and the national target of the British government is a reduction of 30 % by 2025. T

The city’s 60 % target could be brought within reach by means of new regulations, changes in the public’s behavior (fuel-saving driving, use of public transit, and lowering thermostats) and future technological innovations.

Effectively applying all the analyzed abatement levers by 2025 would require an additional investment of about €41 billion, less than 1 % of London’s economic output. This roughly matches the results of the 2006 report by Sir Nicholas Stern, which put the costs of stemming the greenhouse effect at up to 1 % of global gross domestic product per year. On the other hand, accepting an unchecked rise in temperatures could cost 5 to 10 % of global economic output, according to the former chief economist of the World Bank.

Results of the "Sustainable Urban Infrastructure" Study:
^? The greatest potential for savings lies in London’s buildings. They are responsible for about two thirds of total CO₂ emissions in the city. Per capita, that represents 4.3 t of CO₂ per year, a high value compared to other cities. The corresponding figure in Tokyo is 2.9 t of CO₂ per year; in Stockholm it’s only 2.6. By 2025 about 10 mill. t of London’s CO₂ could be eliminated through better insulation of Victorian buildings, more energy-efficient lighting and modern building automation systems. And almost 90 % of that reduction would pay for itself thanks to the resulting energy savings.
^? Greenhouse gas emissions in transport could be reduced by 25 % by 2025—a reduction of 3 mill. t of CO₂ per year. Here, higher-efficiency cars are the most important abatement lever. They could help to eliminate more than 1.2 mill. t of CO₂. And it would be possible to eliminate another 400,000 t of CO₂ in local public transport by using hybrid buses, for example, which consume 30 % less fuel than conventional diesel buses.
^? When it comes to power generation, London could eliminate another 6.2 mill. t of CO₂. At the local level, various combined heat and power plants offer the greatest potential: 2.1 mill. t of CO₂ savings per year. An additional 3.7 mill. t could be achieved at the national level if plant operators were to rely on renewable energies and gas instead of coal for the generation of electricity, for instance.
^? London’s water supply network is roughly 150 years old and loses over 30 % of the water fed into its 4,800 kilometers of lines. This means enough water to fill 350 Olympic-size swimming pools seeps into the ground every day. So for each liter of water not consumed, almost 1.5 liters less must be pumped into the system. By 2025, about 65 million cubic meters of water could be saved annually—some 13 % of total consumption—through economically reasonable measures like dual-flush toilets or more efficient washing machines and dishwashers.
^? About 64 % of London’s municipal waste is currently disposed of in land­fills—a large amount compared to cities such as Tokyo and Stockholm. Given the high and rising landfill fees and taxes in Great Britain, there are eco­nomically attractive alternatives to garbage disposal in landfills. Raw materials can be recycled, and modern technologies can be applied to domestic waste for the purpose of creating new energy sources, whether by converting it into biogas or through direct combustion. The energy thus extracted can be used to supply thousands of households with electricity and heat.

People Made a Difference. The study also shows that urban initiatives should not be limited to CO₂ reductions. It’s equally important to achieve greater consumer acceptance of energy-saving technologies. About 75 % of the potential reduction in CO₂ levels could be realized by individuals and busi­nesses in London if they opted for more efficient technologies such as energy-saving lamps and more economical cars. Changes in regulations, taxes and subsidies, better financing opportunities, and education campaigns can help to change consumers’ attitudes and encourage them to make decisions that are not only economically efficient but also environmentally sound.
                                                                                                                     Petra Zacek