World Bank Document

98 ■ CITIES AND CLIMATE CHANGE

emissions by 13 percent. Further reductions could be achieved by introducing
hybrid buses or increasing loads of both cars and transit.
Th e use of the model allows a back-of-the-envelope calculation of the impact
of potential changes in technology and transport mode on GHG emissions. Th e
model does not have anything to say about the feasibility or the probability
of such a change to occur. Although the rough calculations shown imply that
the combined impacts of technology change and mode shift could be large,
how to achieve these changes remains the main problem to be solved. Most of
the vehicle technology, such as hybrid engines, that reduces fuel consumption
has been around for at least 10 years. Rail transit using electricity has been
common in large cities for more than 100 years. Th e fact that in many cities
the use of transit represents a minority mode raises important questions about

Table 4.3
Potential Impact of Vehicle Shift and Mode Shift on GHG Emissions in
New York City Metropolitan Area

(A) (B) (C)

i

Mode /

Symbol P P

Change in

CO 2 e

emissions P

Change in
CO 2 e
emissions
1 Walk 5% 5% 5%
2 Cycle 1% 1% 1%
3 Car (gasoline) 56% 37.5% −33% 46% −18%
4 Car (diesel) 0.5% 0.5% 0.5%
5 Car (hybrid) 0.5% 19.0% n.a. 0.5%
6 Car (electric) 0% 0% 0%
7 Motorcycle
2-stroke

1% 1% 1%

8 Minibus
gasoline

0% 0% 0%

9 Minibus
diesel

0% 0% 0%

10 Bus diesel 5% 5% 6% 20%
11 Bus natural
gas

10% 10% 12% 20%

12 Rail transit 21% 21% 28% 33%

Tons per day 51,545 36,918 44,698 −13%

Kilograms per year
per commuter

1,418 1,024 −28% 1,240 −13%

Source: Authors’ analysis.
Note: n.a. = not available.