Energy-use benchmarks for the case-study cities

<p><b>Table 1.</b> Energy-use benchmarks for the case-study cities. Comparative state-level benchmark shown in <em>[bracket]</em>. (Note: <em>energy-use data</em>: local retrieved from bottom-up data (ICLEI <a href="http://iopscience.iop.org/1748-9326/8/3/035011/article#erl463816bib23" target="_blank">2010</a>), state retrieved from (EIA <a href="http://iopscience.iop.org/1748-9326/8/3/035011/article#erl463816bib14" target="_blank">2012</a>); <em>employment statistics</em>: local retrieved from (MIG <a href="http://iopscience.iop.org/1748-9326/8/3/035011/article#erl463816bib28" target="_blank">2010</a>), state retrieved from (Census <a href="http://iopscience.iop.org/1748-9326/8/3/035011/article#erl463816bib6" target="_blank">2011</a>); <em>population and households</em>: local retrieved from (MIG <a href="http://iopscience.iop.org/1748-9326/8/3/035011/article#erl463816bib28" target="_blank">2010</a>), state retrieved from (Census <a href="http://iopscience.iop.org/1748-9326/8/3/035011/article#erl463816bib6" target="_blank">2011</a>); <em>vehicles miles traveled (VMT)</em>: local retrieved from (ICLEI <a href="http://iopscience.iop.org/1748-9326/8/3/035011/article#erl463816bib23" target="_blank">2010</a>), state retrieved from (FHWA <a href="http://iopscience.iop.org/1748-9326/8/3/035011/article#erl463816bib16" target="_blank">2008</a>).) </p> <p><strong>Abstract</strong></p> <p>Three broad approaches have emerged for energy and greenhouse gas (GHG) accounting for individual cities: (a) purely in-boundary source-based accounting (IB); (b) community-wide infrastructure GHG emissions footprinting (CIF) incorporating life cycle GHGs (in-boundary plus trans-boundary) of key infrastructures providing water, energy, food, shelter, mobility–connectivity, waste management/sanitation and public amenities to support community-wide activities in cities—all resident, visitor, commercial and industrial activities; and (c) consumption-based GHG emissions footprints (CBF) incorporating life cycle GHGs associated with activities of a sub-set of the community—its final consumption sector dominated by resident households. The latter two activity-based accounts are recommended in recent GHG reporting standards, to provide production-dominated and consumption perspectives of cities, respectively. Little is known, however, on how to normalize and report the different GHG numbers that arise for the same city. We propose that CIF and IB, since they incorporate production, are best reported per unit GDP, while CBF is best reported per capita. Analysis of input–output models of 20 US cities shows that GHG^CIF/GDP is well suited to represent differences in urban energy intensity features across cities, while GHG^CBF/capita best represents variation in expenditures across cities. These results advance our understanding of the methods and metrics used to represent the energy and GHG performance of cities.