TY - JOUR
T1 - Greenhouse gas emission footprints and energy use benchmarks for eight U.S. cities
AU - Hillman, Tim
AU - Ramaswami, Anu
PY - 2010/3/15
Y1 - 2010/3/15
N2 - A hybrid life cycle-based trans-boundary greenhouse gas (GHG) emissions footprint is elucidated at the city-scale and evaluated for 8 US cities. The method incorporates end-uses of energy within city boundaries, plus cross-boundary demand for airline/freight transport and embodied energy of four key urban materials [food, water, energy (fuels), and shelter (cement)], essential for life in all cities. These cross-boundary activities contributed 47% on average more than the in-boundary GHG contributions traditionally reported for cities, indicating significant truncation at city boundaries of GHG emissions associated with urban activities. Incorporating cross-boundary contributions created convergence in per capita GHG emissions from the cityscale (average 23.7 mt-CO2e/capita) to the national-scale (24.5 mt-CO 2e/capita), suggesting that six key cross-boundary activities may suffice to yield a holistic GHG emission footprint for cities, with important policy ramifications. Average GHG contributions from various human activity sectors include buildings/ facilities energy use (47.1%), regional surface transport (20.8%), food production (14.7%), transport fuel production (6.4%), airline transport (4.8%), long-distance freight trucking (2.8%), cement production (2.2%), and water/wastewater/waste processing (1.3%). Energy-, travel-, and key materialsconsumption efficiency metrics are elucidated in these sectors; these consumption metrics are observed to be largely similar across the eight U.S. cities and consistent with national/ regional averages.
AB - A hybrid life cycle-based trans-boundary greenhouse gas (GHG) emissions footprint is elucidated at the city-scale and evaluated for 8 US cities. The method incorporates end-uses of energy within city boundaries, plus cross-boundary demand for airline/freight transport and embodied energy of four key urban materials [food, water, energy (fuels), and shelter (cement)], essential for life in all cities. These cross-boundary activities contributed 47% on average more than the in-boundary GHG contributions traditionally reported for cities, indicating significant truncation at city boundaries of GHG emissions associated with urban activities. Incorporating cross-boundary contributions created convergence in per capita GHG emissions from the cityscale (average 23.7 mt-CO2e/capita) to the national-scale (24.5 mt-CO 2e/capita), suggesting that six key cross-boundary activities may suffice to yield a holistic GHG emission footprint for cities, with important policy ramifications. Average GHG contributions from various human activity sectors include buildings/ facilities energy use (47.1%), regional surface transport (20.8%), food production (14.7%), transport fuel production (6.4%), airline transport (4.8%), long-distance freight trucking (2.8%), cement production (2.2%), and water/wastewater/waste processing (1.3%). Energy-, travel-, and key materialsconsumption efficiency metrics are elucidated in these sectors; these consumption metrics are observed to be largely similar across the eight U.S. cities and consistent with national/ regional averages.
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U2 - 10.1021/es9024194
DO - 10.1021/es9024194
M3 - Article
C2 - 20136120
AN - SCOPUS:77949408541
SN - 0013-936X
VL - 44
SP - 1902
EP - 1910
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 6
ER -