City dwellers should not be so carbon smug

It is often thought that people who live in cities have a smaller carbon footprint than countryside dwellers. Reasons for this include the greater need in rural areas for private motor transport, and the distances involved in transporting goods and services to the point of use.

From a study of urban and suburban population centres in Finland, Aalto University environmental engineers Jukka Heinonen and Seppo Junnila have challenged this interpretation. The researchers found that personal carbon emissions are much the same in cities and rural areas. Carbon dioxide emissions responsible for anthropogenic climate change are, say the two geomatics specialists, dependent on consumption levels rather than place of residence.

At the core of Heinonen and Junnila’s model is the allocation of carbon emissions to the place of consumption, and not the point of production, as has traditionally been used. This, along with a life cycle assessment which looks at production, business transactions and consumption statistics, is said to allow carbon use to be more accurately tracked.

Heinonen and Junnila studied populations in the Helsinki and Tampere regions, and found that the greatest impacts on carbon footprint are housing energy, building construction and maintenance, and mode of transport. Countryside car use may increase the carbon footprint, but its impact is minor when compared with other factors.

Further reading

Jukka Heinonen & Seppo Junnila, “Implications of urban structure on carbon consumption in metropolitan areas”, Env. Res. Lett. 6, 014018 (2011)