Dense downtown living more carbon intense due to higher consumption: a case study of Helsinki

Abstract

Hindering urban sprawl is one of the main goals for contemporary urban planning. Urban density is considered crucial in climate change mitigation since it reduces automobile dependence and decreases unit sizes, for example. This letter analyzes the effect of density in a city context. In the study the Finnish capital Helsinki is divided into two areas of different urban densities: the high density downtown area and the more scarcely populated suburbs. The study is a continuation of a recently published study on the implications of urban structure on carbon emissions, and analyzes further the main finding of the first study-that higher urban density might have negligible or even reverse effect on the per capita carbon emissions. Similarly to the previous study, a consumption based tiered hybrid life cycle assessment (LCA) approach is employed in order to produce a comprehensive assessment, free of territorial boundaries and system cutoffs typical of traditional LCAs. Based on the findings of the previous study, it is hypothesized that when assessing city level carbon dioxide emissions from a wider, consumer oriented LCA perspective, increased urban density may not necessarily reduce carbon emissions. Surprisingly, the study finds that carbon dioxide equivalent (CO 2 e) emissions are substantially higher in the dense downtown area than in the surrounding suburbs, which is suggested to imply that the increased consumption due to the higher standard of living increases emissions more than the higher density is able to reduce them. The results demonstrate that, while increasing urban density can be justified from a number of ecological, social and economic viewpoints, density is not necessarily a key parameter in the particular case of climate change. In cities like Helsinki, where wealth is concentrated in the downtown area, climate policies should give higher priority to the energy consumption of buildings, to alternative energy production and distribution modes, as well as to low carbon consumption within the city.

Life-Cycle Energy Implications of Downtown High-Rise vs. Suburban Low-Rise Living: An Overview and Quantitative Case Study for Chicago

“…These data suggest that when accounting for building construction, building energy use, transportation infrastructure, and travel modes across these two locations, downtown high-rise living is estimated to account for approximately 25% more life-cycle energy use than suburban low-rise living based on the methods and best estimates of inputs used herein. This result is in conflict with some early studies by Norman et al and Perkins et al [7,55], but generally in line with others [15,16]. Interestingly, building operational energy use was estimated to be the largest contributor of the total life-cycle energy in both the downtown high-rise and suburban low-rise cases (even when accounting for uncertainty in building OE for these building types), followed by vehicle operational energy.…”

“…A few recent studies that have done so for cities such as Helsinki, Finland; Halifax, Canada; and Adelaide, Australia suggest that high-density urban areas may not actually lead to more energy-or carbon-efficient lifestyles [14][15][16][17], contrary to common beliefs. However, we are not aware of any similar comparisons in U.S. cities.…”

Towards a comprehensive system of methodological considerations for cities' climate targets

“…Heinonen and Junnila (2011a), Heinonen et al (2011, Weber and Matthews (2008) and Moll et al (2005). This way of estimating and accounting for emissions is also proposed by Ramaswami et al (2011) and is one of the accounting approaches that will be supported in the forthcoming ICLEI Community-Scale GHG Emissions Accounting and Reporting Protocol (ICLEI, 2011).…”

“…Fortunately, cities are also reported as having the potential to support more resource-efficient ways of meeting needs and wants than suburbia or the countryside (Mindali et al, 2004;Williams, 1999). While this has been supported by some studies (Dhakal and Shrestha, 2010;Glaeser and Kahn, 2010), others state the opposite and argue that cities only appear more resource-efficient as a result of inferior systems thinking, meaning that many cities actually have a much larger carbon footprint than is typically accounted for (Heinonen and Junnila, 2011a;Heinonen et al, 2011;Hillman and Ramaswami, 2010;Kennedy et al, 2010).…”

Are the Greenhouse Gas Implications of New Residential Developments Understood Wrongly?

“…This enables comparisons between the emissions related to different life cycles as well as drawing meaningful policy implications. Both models are developed by the authors and have been utilized in previous studies and published recently in several academic journals [16,17,[21][22][23][24].…”