Global Warming

284 Energy andtransport for thefuture

Figure 11.9Growth of world
motor vehicle population,
1946–96.

(see box below) – more efficient engines,lightweight construction and

low-air-resistance design – while maintaining an adequate performance.

The second action is to plan cities and other developments so as to

lessen the need for transport and to make personalisedtransport less

necessary – work, leisure and shopping should all be easily accessible

by public transport, or by walking or cycling. Such planning needs also

to be linked with a recognition of the importance of ensuring that public

transport is reliable, convenient, affordable and safe. The third action is to

increase the energy efficiency of freight transport by making maximum

use of the most energy-efficient forms of freight transport, e.g. rail or

water rather than road or air and by eliminating unnecessary journeys.

Air transport is growing even faster than motor transport. Global

passenger air travel, as measured in passenger-km, is projected to grow at

about five per cent per year over the next decade or more and total aviation

fuel use – including passenger, freight and military – is projected to

increase by about three per cent per year, the difference being due largely

to increased fuel efficiency.^19 Further increases in fuel efficiency are

expected but they are unlikely to keep up with the increase in the volume

of air transport. A further problem with air transport, as mentioned in

Chapter 3 page 52, is that its carbon dioxide emissions are not the only

contributor to global warming; increased high cloudinessdue to other

emissions produce an effect of similar or even greater magnitude. Further

research directed at understanding the climatic effects of aircraft and how

they may be reduced is urgently required.

Energy savings in industry

Substantial opportunities exist for efficiency savings in industry. The

installation of relatively simple control technology often provides large