Technology can make cars less damaging to the environment, but it should be only be seen as part of a wider effort to reduce the negative impact of car use.

Some facts

• Cars produce one quarter of the world's man-made greenhouse gas emissions [1].
• The world motor vehicle population of is predicted to rise from 640 million in 1996 to 1.1 billion in 2020 [3]. (Note that globally there was only one car for every ten people in 1996)
• New Zealand and Australia have two of the most inefficient transport systems in the world. New Zealand has a staggering 3.7 million cars for just 4.1 million people.
• 42% of New Zealand's energy is used for transport [4].
• Globally road accidents cost 1.2 million lives and 50 million serious injuries per year [2], and massive indirect cost to our lives and health systems from lack of exercise and air pollution.
• Car based living has contributed to obesity and type II diabetes epidemics in Australasia.

Andy Singer, No Exit

Clean fuels?

Hydrogen, diesel, ethanol, methanol, compressed air and electricity can be all be used to power cars and all can be extracted from renewable sources or from fossil fuels.  All in cases they still leave significant environmental footprints. When extracted from fossil fuels none of these technologies greatly reduce life cycle greenhouse emissions.

Hydrogen is at least as difficult to create from renewable sources as electricity. If extracting it from water the electricity required would result in no net reduction in CO₂ [5-8]. Despite this carmakers and ignorant news reporters frequently claim hydrogen is the solution to all the world's problems.

Fundamental problems

Though some of the issues with today's cars have technology solutions, there will always remain problems fundamental to car-based transport systems, they include:

• Unsustainable energy consumption.
• The massive environmental cost of producing and disposing of cars and car parts.
• Urban sprawl.
• Road and car park construction and traffic congestion. The latter guarentees that in any large city only some can drive, while the rest of us train, cycle, bus or walk but have to tolerate the negative effects of others' cars.
• Health effects of sedentary car based life styles.

These problems can only be solved by making better use of other transportation, and more intelligent decisions about where we allow cars and what to use them for.

[1] World Resources Institute, (2004). In many western countries the proportion is higher.
[2] "World report on road traffic injury prevention", World Health Organisation, Geneva, (2004)
[3] "Climate Change 2001: Mitigation" UN IPCC, working group III, Norway (2001).
[4] EECA (NZ) Transport energy facts
[5] EECA (NZ) Draft eco-efficient motor vehicles strategy
[6] Energy saving trust (UK) Fueling road transport
[7] David Suzuki Foundation (Canada) Fuel Cells, a green solution?
[8] MIT Lab. for Energy and Environment Comparative assessment of fuel cell cars (2003)

Further Reading
International Energy Agency, "Cars and climate change" (1993)
The Engineer, "Hydrogen hoax, fueling a myth", pp. 25-29, 21 Feb (2003)
European fuel cell forum "The future of the hydrogen economy: bright or bleak" (2003)
An article by Jane Holtz Kay