260 ■ CITIES AND CLIMATE CHANGE
culture, economic makeup, and population densities. In addition to the energy
directly consumed by cities, we should recognize a wide range of emissions
associated with the production of the goods and services that are consumed
within cities but that may have been produced elsewhere.
Th is thematic area brings together examples of research from around the
world on how cities may decarbonize over the coming years and decades.
When planning for reducing GHG emissions, cities must recognize their cur-
rent emissions sources and how they may seek to reduce these emissions, with-
out increasing emissions elsewhere. With the global population expected to
increase further in coming decades, and with much of this growth expected to
take place in cities, how future populations live, work, and travel will determine
the energy used to perform these tasks and, therefore, the signifi cant part of
their potential emissions.
Th e application of mitigation policies at the city scale remains in its infancy.
Although targets for GHG reductions and (or through) renewable energy
implementation are regularly touted, the policy linked to delivering the tar-
gets does not always enjoy the same clarity. As a consequence, it is important
to learn from those cities that have begun to implement change. Th is is taken
forward in “A Comparative Analysis of Global City Policies in Climate Change
Mitigation” by Croci, Melandri, and Molteni and in “A Comparative Study of
Energy and Carbon Emissions Development Pathways and Climate Policy” by
Phdungsilp. Th e former considers a range of the world’s global cities, whereas
the latter concentrates on Southeast Asian cities.
Th ese analyses are particularly complemented by the detailed work of van
den Dobbelsteen and others in their paper on the REAP (Rotterdam Energy
Approach and Planning) methodology, “Towards CO 2 Neutral City Planning—
Th e Rotterdam Energy Approach and Planning (REAP).” Th is team modeled
the current and potential future energy requirements of Rotterdam and com-
bined it with available renewable energy resources within the city. Th e meth-
odology follows established principles of mitigation, namely, measuring energy
consumption, establishing areas for reduction, and minimizing waste fl ows.
Th is structured approach, when considered with the wider documentation that
exists online, aff ords a variety of graphical ways to communicate to wide audi-
ences the types of changes necessary to deliver emissions reductions over dif-
fering time scales.
A city-level mitigation strategy is inevitably a function of its parts, with
buildings contributing a sizeable component of a city’s energy consumption.
Th is requires investigating options for reducing energy consumption in the
buildings sector in diff erent contexts and creating a situation where buildings,
both existing and future, may be considered “more sustainable.” Th e transition
to this point will vary across cities. Th e future energy consumption of a build-