Greenhouse Gas Emission Baselines for Global Cities and Metropolitan Regions

Abstract

SummaryGreenhouse gas (GHG) emissions baselines are presented for 44 urban areas (cities or metropolitan regions). The types of methodology that have been used to attribute GHGs to urban areas are reviewed. All are essentially adaptations or simplifications of the IPCC guidelines, and incorporate the WRI/WBCSD concepts of Scope 2 and 3 "crossboundary" emissions. Analysis of previous studies shows where specific differences in methodology exist. Some Scope 3 emissions such as those embodied in materials, food, and fuel consumed in cities, have only been quantified in a few studies, and should be included in further studies. Baseline emissions are presented with and without emissions from: industrial processes; and agriculture, forestry and other land-use (AFOLU) (both of which may be incomplete); as well as: waste; and aviation / marine (for which there are differences in methodology). Despite these often minor differences, the potential clearly exists to establish an open, global protocol for quantifying GHG emissions attributable to urban areas.

Greenhouse Gas Emissions from Waste Management—Assessment of Quantification Methods

“…CH 4 emissions are not controlled). Other possible GHG sources from solid waste include 7 • Combustion of fossil-derived carbon in incineration systems resulting in the release of CO 2 • Production of CH 4 from anaerobic conditions within composting operations • Release of nitrous oxide (N 2 O) during nitrification in compost piles • Leakage of CH 4 from AD reactors • Collection and transportation of waste to transfer and treatment sites (indirect). Although policy measures to reduce GHG emissions from MSW appear straightforward (such as improved recycling of wood products and diversion of food wastes), inaccurate quantification of these may distort the issue's scale (and economic feasibility if carbon pricing is part of the rationale for a mitigation project).…”

Testing the efficacy of voluntary urban greenhouse gas emissions inventories

“…To be sure, there are other datasets in the literature (Butler and Lawrence 2009;Butler et al 2008;Dhakal 2010;Duren and Miller 2012;Hoornweg et al 2011;Hsu et al 2016;Kennedy et al 2014;Kennedy et al 2011;Marcotullio et al 2014;Sovacool and Brown 2010), albeit with smaller number of cities. Some of them do not provide comparability across the board (Al-areqi et al 2014), are limited to one country (US Census Bureau 2007; US Census Bureau 2010) or do not provide bottom-up estimates (Dodman 2009;Lee and Koski 2015;Marcotullio et al 2014).…”

“…For all analyses we still have representation from North America, Europe, Asia, developing and developed nations and for most analyses the number of cities considered is greater than most similar comparative studies in literature, i.e. having bottom up figures or utilizing small set of cities (Butler and Lawrence 2009;Butler et al 2008;De Sherbinin and Chen 2005;Dhakal 2010;Duren and Miller 2012;Gately et al 2015;Kennedy et al 2011;Marcotullio et al 2014;Satterthwaite 2008;Sovacool and Brown 2010;Xu et al 2015). This makes this study one of the largest of its kind with such a varied set of cities from different regions and geopolitical contexts.…”

Determinants of cities' GHG emissions: a comparison of seven global cities

“…As a result, GHG emission figures that have been attributed to cities are not always comparable. Several authors have pointed out methodological differences among inventories, highlighting that most of approaches used are adaptations of the Intergovernmental Panel on Climate Change (IPCC) guidelines elaborated for national inventories (Kennedy et al, 2009a).…”

“…For waste, several estimation methodologies are in use for local inventories, showing discrepancies among them (Kennedy et al, 2009a). Different methodologies have been applied also to cities of this paper's sample and, for this reason, this sector has not been included in the present work for analysis.…”