GREENHOUSE GAS EMISSION BASELINES ■ 29counting, ICLEI’s fi nal reporting standard includes all Scope 1 emissions, plus
additional emissions from electricity, heat, steam, solid waste, and waste water
that occur outside of the geopolitical boundary.
Moving to a slightly larger scale, the GRIP methodology, developed at the
University of Manchester, has primarily been applied to European regions
(although it is also being applied in the United States), typically consisting
of a large urban center with surrounding industrial and agricultural lands
(see defi nitions in table 2.1). GRIP reports emissions from the six main
GHGs (the Kyoto basket): carbon dioxide (CO 2 ), methane (CH 4 ), nitrous
oxide (N 2 O), hydrofl uorocarbons, perfl uorocarbons, and sulfur hexafl uoride
(SF 6 ). Th e methodology closely follows the IPCC guidelines by reporting,
for example, energy and industrial process emissions by detailed subsectors.
Indeed, results are developed so as to be comparable with national invento-
ries as well as other regions. Th e GRIP methodology is also consistent with
approaches used to study other cities or city regions. For example, it does
assign electricity emissions associated with electricity generation to the end
user (for example, GRIP reports Scope 1 and 2 emissions and some Scope 3
emissions).
A particular strength of the GRIP methodology is its ability to recognize
and manage diff erences in data quality. GRIP has a three-level reporting
scheme, where level 1 (green) is for the most certain data, level 2 (orange) is
for intermediate-quality data, and level 3 (red) is lower-quality data; the last
example usually is scaled from information in national inventories. (Th e levels
have some similarities with IPCC tiers but are not the same.) Th e color coding
is used in the reporting procedure to provide a clear indication of uncertainty
in the results.
Overall, the urban GHG methodologies used by ICLEI and GRIP, as well
as the academic studies, are fairly consistent with one another. All draw upon
IPCC guidelines, with many incorporating out-of-area Scope 2 and Scope 3
emissions. Th e main diff erences lie with which emissions, particularly Scope 3,
are included in fi nal reporting.
Review of Methodology for Urban Baselines
Th is section identifi es the specifi c diff erences in methodology between selected
urban GHG studies and explains how the approaches taken relate to the IPCC
and WRI/WBCSD procedures. Table 2.2 shows the emissions subcategories
for which there are diff erences between studies. Emissions are discussed under
the four main categories of the IPCC: Energy; Waste; Industrial Processes and
Product Use; and Land Use, Agriculture, and Forestry.