88 ■ CITIES AND CLIMATE CHANGE
Hypothesis 1: Price signals, including energy prices and carbon market–
based incentives, road tolls, and transit fares, are the main drivers of techno-
logical change, transport modal shift , and land-use regulatory changes.
Hypothesis 2: Price signals could shift transport mode from individual cars to
public transit for trips from the periphery to the central business district (CBD)
only in cities that are densely populated (more than 50 people/hectare (ha) in
built-up areas) and already dominantly monocentric.
GHG Emissions and Urban Transport
Urban GHG emissions per person in large cities are a fraction of the national
average (fi gure 4.1). Th is diff erence appears as a paradox because cities have a
higher gross domestic product (GDP) per person than the national average,
and it is usually assumed that higher GDP means higher GHG emissions. In
fact, modern cities with a large proportion of service jobs consume less energy
per capita than smaller towns and rural areas. However, because GHGs are
emitted in urban areas by a very large number of small sources—cars, appli-
Figure 4.1 CO 2 Emissions in Cities Compared with Countries
Source: EIU 2008; World Resources Institute 2009.
Note: CO 2 e = carbon dioxide equivalent.
United StatesUnited KingdomNew York City London Tokyo Stockholm RomeJapan
SwedenItalyCO 2 e emissions per capita
25,00020,00015,00010,000Kilograms COe per capita per year 25,000