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. 2013 Jun 4;8(6):e64727.
doi: 10.1371/journal.pone.0064727. Print 2013.

Does size matter? Scaling of CO2 emissions and US urban areas

Michail Fragkias  1 , José Lobo, Deborah Strumsky, Karen C Seto
Affiliations

Does size matter? Scaling of CO2 emissions and US urban areas

Michail Fragkias et al. PLoS One. .

Abstract

Urban areas consume more than 66% of the world's energy and generate more than 70% of global greenhouse gas emissions. With the world's population expected to reach 10 billion by 2100, nearly 90% of whom will live in urban areas, a critical question for planetary sustainability is how the size of cities affects energy use and carbon dioxide (CO2) emissions. Are larger cities more energy and emissions efficient than smaller ones? Do larger cities exhibit gains from economies of scale with regard to emissions? Here we examine the relationship between city size and CO2 emissions for U.S. metropolitan areas using a production accounting allocation of emissions. We find that for the time period of 1999-2008, CO2 emissions scale proportionally with urban population size. Contrary to theoretical expectations, larger cities are not more emissions efficient than smaller ones.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Cross-sectional log-log regressions for years (A) 1999 and (B) 2008.
Figure 2
Figure 2. Ranking of residuals from the scaling regression for year 2008 (MSA observations in red; micropolitan area observations in blue).
See this image and copyright information in PMC

References

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