In recent years, various studies have suggested that city dwellers ought to produce fewer greenhouse-gas emissions than those living in the countryside. It was thought that the higher density of living typical of urban environments would promote a more efficient use of energy, as people travel less and live in more confined spaces.

But such studies ignored the fact that cities are usually the wealthiest places. Wealth brings greater consumption and extra greenhouse-gas emissions, and researchers pointed out that this might balance any carbon "savings" from denser living. In 2011, Seppo Junnila and Jukka Heinonen at the Aalto University of Engineering studied the carbon footprints of people living in several places in Finland and found that there was indeed little difference in greenhouse-gas emissions between those living in the city and the countryside.

Now, Junnila and Heinonen have extended their study to include people living all over Finland. Their revised analysis suggests that city dwellers are not just as bad, but worse, for greenhouse-gas emissions than country folk. "The results are very interesting since they indicate that the more urban type of living cannot reduce our greenhouse-gas emissions [below those of country lifestyles], at least in the type of conditions in Finland, where the highest affluence concentrates to the most urbanized areas," said Heinonen.

The Aalto researchers analysed monetary consumption and time-use data of some 4400 individuals. Using a model known as ENVIMAT, which equates greenhouse-gas emissions to money spent on different goods or services, the researchers formed greenhouse-gas profiles for average residents of four different types of municipality in Finland: rural, semi-urban, urban and the country's largest urban area, Helsinki.

The results showed that the average Finn living in the countryside had a carbon footprint of 8900 kg/year, which rose to 9600 kg/year for an average Finnish city dweller. Meanwhile, Finns living in Helsinki had a carbon footprint of 10,900 kg/year.

Part of the extra footprint for city dwellers can be blamed on a higher expenditure on clothes and technology, said Junnila and Heinonen. But the researchers point to another problem, which they call parallel consumption: using city-based services that the home can provide just as well. Examples of parallel consumption include eating at restaurants, going to cinemas and using laundrettes. "City residents sort of 'extend' their living space to all the commercial service spaces around them," said Heinonen. "The phenomenon of parallel consumption is present in virtually all kinds of human settlements, but it seems to be much stronger in cities."

The researchers call their analysis "very broad", in the sense that there may be a lot of variation in carbon footprints among city and countryside residents caused by other factors, such as housing types and possession of private vehicles. However, they say that these issues will be addressed by a forthcoming study.

The analysis is published in Environmental Research Letters (ERL).

Related links

Related stories