Greater use of public transport and denser housing make urbanites more eco-friendly than their rural counterparts
Adam Vaughan, guardian.co.uk 23 Mar 09;
The image of cities is often traffic-clogged, polluted and energy-guzzling, but a new study has shown that city dwellers have smaller carbon footprints than national averages.
The report by London-based International Institute for Environment and Development (IIED) looked at 11 major cities on four continents, including London, Tokyo, New York and Rio de Janeiro.
It found per capita greenhouse gas emissions for a Londoner in 2004 were the equivalent of 6.2 tonnes of CO2, compared with 11.19 for the UK average.
The rural northeast of England, Yorkshire and the Humber, were singled out for having the highest footprints per capita in the UK.
In the US, New Yorkers register footprints of 7.1 tonnes each, less than a thrid of the US average of 23.92 tonnes.
The use of public transport and denser housing are two of the reasons for urbanites' comparatively low carbon footprints, the authors said, adding that the design of cities significantly affects their residents' emissions.
"Tokyo has considerably lower emissions per person than either Beijing or Shanghai and this shows clearly that prosperity does not lead inevitably to greater emissions," said report author David Dodman. "Well-designed and well-governed cities can combine high living standards with much lower greenhouse gas emissions."
The report coincides with a study published today by the UK's Commission for Architecture and the Built Environment, which called for more spending on parks and trees in cities to create jobs and cut climate change emissions.
The IIED is not the first organisation to suggest city living is greener than living in the countryside: last summer the Brookings Institute said residents in US cities had 14% lower footprints than the US average.
The authors of this new report, however, admit that assessing emissions is not an exact science because different countries and cities employ different methodologies for counting CO2 emissions, making a precise like-for-like comparison difficult.
Most city dwellers' emissions are also still too high to curb climate change, despite being low compared with national averages. "With the exceptions of São Paulo and Rio de Janeiro, all of the cities surveyed already exceed the per capita figure" needed to keep CO2 levels below 450 parts per million, warned Dodman.
City-dwellers emit less CO2 than countryfolk: study
Michael Szabo, Reuters 23 Mar 09;
LONDON (Reuters) - Major cities are getting a bad rap for the disproportionately high greenhouse gases they emit even though their per capita emissions are often a fraction of the national average, a new report said on Monday.
Published by the International Institute for Environment and Development, the report found that urban residents generate substantially lower greenhouse gas emissions, which scientists blame for global warming, than people elsewhere in the country.
"Although the concentration of people, enterprises, vehicles and waste in cities is often seen as a 'problem', high densities and large population concentrations can also bring a variety of advantages for ... environmental management," said the report.
The report brought together the findings of several studies published in the past 13 years to determine if cities have a disproportionately negative effect on global emissions.
"The real climate change culprits are not the cities themselves but the high consumption lifestyles of people living across these wealthy countries," said report author David Dodman.
He analyzed the per capita emissions from major cities in Europe, Asia, North America and South America.
According to the report, London emitted 44.3 million tons of CO2 in 2006, or 8 percent of the national total.
With a population of around 7 million, per capita emissions in London were only 6.18 tons per person, or 55 percent of the UK's 2004 average of 11.19 tons.
In the United States, New York City had emissions of 58.3 million tons in 2005, or around 7.1 tons per person. U.S. per capita levels were more than triple at 23.92 tons in 2004.
The report noted the density of New York's buildings, the smaller-than-average dwelling sizes and the reliance on public transportation as reasons for the large difference.
Washington DC's per capita emissions of 19.7 tons were closer to the national average due to a high number of government office buildings versus a small metropolitan population, the report said.
Brazil's Sao Paulo and Rio de Janeiro, the only two South American cities analyzed, both had substantially lower per capita emissions due to the country's widespread deforestation and large amounts of livestock.
PRODUCTION VERSUS CONSUMPTION
The report analyzed only the emissions emitted directly by a city rather than those generated by the production of the goods consumed by its residents.
"Production-oriented" centers like Beijing and Shanghai, which house many factories outsourced by rich countries, were the only cities with higher per capita emissions than the national average.
"Many polluting and carbon-intensive manufacturing processes are no longer located in Europe or North America, sited elsewhere in the world to take advantage of lower labor costs and less rigorous environmental enforcement," the report said.
Anna Tibaijuka, executive director of UN-Habitat, said in a presentation last week that cities emit 50-60 percent of greenhouse gases, rising to 80 percent if you include the indirect emissions generated by city-dwellers.
She said more than half of the world's population now lives in cities but they consume 75 percent of global energy.
(Additional reporting by Alister Doylein Oslo; Editing by Michael Urquhart)
City dwellers 'harm climate less'
Nora Schultz, New Scientist 23 Mar 09;
City lights may burn bright, but overall the greenhouse gas emissions of large cities are far below those of rural areas, a new report finds.
David Dodman at the International Institute for Environment and Development in London, who led the study, says previous claims that cities contribute disproportionately to global climate change are unfounded.
"Historically, people have associated pollution and environmental damage with cities and, as far as climate warming goes, it is true that urban areas have large energy consumption," he says. "But many emissions come from rural areas, and methane is a far more potent greenhouse gas than carbon dioxide."
To discover just how bad city life is for the climate, Dodman compared greenhouse gas emissions in 12 large cities around the world with the average emissions of their respective countries. He found that, on average, city dwellers emit fewer greenhouse gases than the average for their country (see the complete list at bottom).
'Critical mass'
In terms of per-capita emissions, the most environmentally unfriendly city of those studied is Washington, DC. With 19.7 tonnes of CO2 equivalent per head, the carbon footprint of each citizen there is nearly three times that of other large cities in developed nations. Dodman blames this on the amount of office space in the city. However, residents of DC still emit only 82.4% of the US average.
This holds true for other wealthy cities. Per capita emissions in New York, Toronto and Barcelona are only a third of their national average, and the emissions of Tokyo, London and Seoul come in at about half of their countries' level.
"There are density-related advantages for both travel and heating," says Dodman. "When you have a critical mass of people like in London or New York, public transport becomes a feasible option for many, while people in more rural areas rely more on cars. And a flat that is surrounded by others is more efficient to heat than a free-standing house."
On paper, citizens of the Brazilian cities Rio de Janeiro and Sao Paulo have small carbon footprints, emitting only 28 and 18% of the country's average. But according to Dodman, this is "more because the Brazilian national profile is heavily dominated by deforestation and agriculture, not because those cities are doing particularly well".
Beijing and Shanghai, in contrast, emit more than double China's national average, but this most likely results from their thriving manufacturing industries and city boundaries encompassing more rural areas than elsewhere, he says.
'Outsourced emissions'
Jim Hall at the Tyndall Centre for Climate Change Research in the UK says that, although dense cities may reduce transport emissions and act as "hugely beneficial" hubs of innovation, their total effect on the climate also depends on measures that were not captured by the current analysis.
"Cities where the service sector dominates have outsourced carbon intensive industries to developing countries, yet are still voracious consumers of industrial products," Hall says. "There is a large discrepancy between production-based and consumptions-based metrics of emissions."
Dodman agrees. "The emissions for a pair of shoes made in China and sold in the UK are currently allocated to China, not to [the UK], so it is fair to ask whether we should count emissions according to the location of production or the location that is driving the consumption."
Dodman also stresses that despite comparing well to their nations' average carbon footprint, western cities have room for plenty of improvement. In the list of top climate offenders, their emissions still dwarf those from cities in developing nations.
Dirty dozen?
The following list shows the greenhouse gas emissions per person in the 12 cities analysed – in descending order of emissions. The cities were chosen on the basis of good data being available for comparison and to cover Asia, Europe and North and Latin America.
1. Washington, DC, US – 19.7 tonnes of CO2 equivalent
2. Glasgow, UK – 8.4 tonnes
3. Toronto, Canada – 8.2 tonnes
4. Shanghai, China – 8.1 tonnes
5. New York City, US – 7.1 tonnes
6. Beijing, China – 6.9 tonnes
7. London, UK – 6.2 tonnes
8. Tokyo, Japan – 4.8 tonnes
9. Seoul, South Korea – 3.8 tonnes
10. Barcelona, Spain – 3.4 tonnes
11. Rio de Janeiro, Brazil – 2.3 tonnes
12. Sao Paulo, Brazil – 1.5 tonnes
Journal Reference: Environment & Urbanization (DOI: 10.1177/0956247809103016)
