Christopher Kennedy · Environmental Science & Technology 2009 · Comparative cross-sectional study · n=10

Greenhouse Gas Emissions from Global Cities

Cited 727 times in the scientific literature.

Level 4 - case-series / case-control

Cross-sectional comparative case series (graded by design analogy, non-clinical).

OpenAlex W1972194201 · doi:10.1021/es900213p · record verified 2026-08-26

What was done

The authors analyzed greenhouse gas emissions across 10 global cities to determine how emissions differ and identify underlying drivers. The evaluation examined the influence of geophysical factors (climate, access to resources, gateway status) and technical factors (power generation, urban design, waste processing, public transit availability, and personal income), incorporating upstream emissions from fuels alongside direct end use.

What was found

Including upstream emissions from fuels increased total greenhouse gas emissions attributable to cities by up to 25% over direct end-use estimates. Differences between cities were driven by transit infrastructure and income-related heating and industrial fuel demands. Specific numerical baseline emissions, confidence intervals, and individual city data were not reported in the abstract.

Why it matters

This work demonstrates that direct-only carbon accounting materially underestimates municipal footprints and highlights the need to include upstream fuel lifecycles in urban emissions inventories.

Limits

The sample is limited to 10 cities, restricting generalizability to diverse global urban forms. The abstract reports only a single quantitative outcome (up to 25%) without baseline metrics, variance, or specific statistical testing details. As an observational comparison, it cannot definitively establish causal relationships between specific urban designs and emission reductions.

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