Cities and Climate Change – Global Report on Human Settlements, a report released this week by UN-HABITAT, warns that cities and urban centers have “become the real battle-ground in the fight against climate change and cities will neglect their role in responding to the crisis at their peril. Not just their own peril but that of the world.”
Cities occupy two percent of Earth’s land mass but contribute up to 70 percent of global greenhouse gas emissions, says the report. Most of the world’s human population now lives in cities, and estimates are that by 2030 59 percent will live in cities. In developed countries, fully 81 percent of the population will be urbanized, and 55 percent in developing countries. Every year 67 million more people become urban dwellers, 91 percent of those in developing countries. It is this furious pace of urbanization combined with the demand for development that “poses the major threat.”
“Cities are responsible for the majority of our harmful greenhouse gases. But they are also places where the greatest efficiencies can be made. This makes it imperative that we understand the form and content of urbanization so that we can reduce our footprint,” said Joan Clos Executive Director of UN-HABITAT. “Understanding the contribution of cities to climate change will help us intervene at the local level. With better urban planning and greater citizen participation we can make our hot cities cool again.”
Determining a city’s impact on climate
The report highlights five major factors that contribute to the impact on climate change from urban centers:
- Geographic location: where a city is located determines energy demand for heating, cooling, and lighting.
- Demographics: how many people concentrated in an area determines demand for space and services.
- Urban form and density: compact cities are generally more efficient and have lower per capita emissions that sprawling urban metropolises.
- Economic activity: the major economic and business activities with a city – are their concentrations of heavy industry emitting large quantities of greenhouse gases?
- Average income: the wealth and consumption patterns of an urban area determine energy and resource demand.
Comparing city and national per capita greenhouse gas emissions
The report shows how per capita greenhouse gas emissions can vary between cities, even within the same country. Washington DC, for example, has relatively high emissions proportionally. With little heavy industry, the city has a small population in relation to the number of office buildings for government and support functions. By contrast, New York City’s emissions are low, per capita, for a wealthy city in a developed country, owing in part to its high population density, small dwelling size, extensive public transport system, and number of older building the rely on natural daylighting and ventilation.
Urban emissions by sector
Isolating urban greenhouse gas emissions by sector is a complex task but worth the effort in order to incorporate effective policies and mitigation practices into urban management and development plans. The Intergovernmental Panel on Climate Change estimates that currently 14 percent of global greenhouse gas emissions come from agriculture and another 17 percent from forestry. The rest comes mostly from urban based sources for the combustion of fossil fuel for electricity, transportation, cooking, and industry.
The report delineated the following breakdown of sector-by-sector emissions:
- Transportation – 13 percent of global greenhouse gas emissions. Transportation accounts for 23 percent of all energy related emissions.
- Industry – 19 percent of global GHG emissions. As outlined above, emissions vary widely depending on the predominate economic activity of a particular city. In Shaghai, 90 percent of energy produced was consumed by the industrial sector between 1995 and 2005. The deepwater port town of Saldhana Bay in South Africa emits 50 tonnes of GHG per capita annually. In Prague that figure is 0.43 tonnes per capita per annum.
- Buildings – 8 percent of global GHG emissions. The IPCC estimates that residential and commercial building emit 10.6 billion tonnes of GHG equivalent every year.
- Waste – 3 percent of global emission.
Cities at the forefront of climate change
Leadership on climate change action at the national and international level is modest at best, and for some key players – like, unfortunately, for the United States – almost entirely absent. It is with local municipalities that real innovation and change can occur, driving the larger international forces.
The UN-HABITAT report emphasizes that with the challenges faces cities comes “unprecedented opportunities to act and change their future.” It is within cities that the engine of change drives forward with real “nuts and bolts” technical, economic, and political power. It is within cities and urban centers that solutions are most needed, and it is within cities that solutions are born.
“City leaders are where the action is and they are better placed than national politicians to effect immediate change,” said Clos, a former mayor of Barcelona. “Depending on their national contexts and histories, city authorities can have a considerable level of influence over both greenhouse gas emissions and adaptation to climate change. Cities and citizens can make a global difference.”
A few key alliances of local municipalities joining forces to lead on climate change include:
- ICLEI – Local Governments for Sustainability. An association of more than 1200 local governments from across the globe committed to sustainable development. Among its various programs is the ICLEI Climate Program.
- Large Cities Leadership Council - also known as C40 Cities. C40 was created in 2005 to forge alliances and cooperation among some of the largest cities from all regions of the world.
- World Mayors Council for Climate Change – a 50 member international alliance formed in 2005 addressing climate, biodiversity, and Millennium Development Goals.
Cities have become a great battleground for a sustainable future. Battles are won by decisive and insightful leadership. Perhaps it is in local action – cities, local governments, individuals – that the battle can be engaged, and eventually won.
- UN report: Cities ignore climate change at their peril (environmentaleducationuk.wordpress.com)
- Cities ‘feeling heat of climate’ (bbc.co.uk)
- Study Says Rethinking Cities Is Key to Climate Change (news.sciencemag.org)