Sustainable Transport and the Environment Guide - Unite the Union

contributing to rainforest destruction. This worsens climate change because the trees
absorb and store a huge amount of CO 2 .
As well as potentially creating more of a climate problem than they solve, agrofuels
have also been accused by the UN’s Food and Agriculture Programme of displacing
food production and making it more expensive. Greenpeace has calculated that
replacing a mere 10% of the world’s diesel with biodiesel would use up three quarters
of the world’s soya, rapeseed and palm oil production 23 .
Biomass like wood and waste can also be used to generate energy, and wood can be
grown on land that is not suitable for agriculture. There has been much talk of
converting these to liquids or gas to use as ‘2 nd generation biofuels’. However
burning these substances to generate electricity or digesting them to generate gas, is
far more efficient than turning them into liquid fuels.
Given these concerns government biofuels targets remain under review.
Recycled biofuel is a different matter – the material (for example, recycled chip fat)
would otherwise end up in landfill so it is a genuinely ‘green’ way of fuelling
vehicles. It could power up to 2 per cent of the UK’s freight.
Hydrogen
Hydrogen gas is a way of storing energy, not a source of energy – a bit like a battery.
To produce and compress it, you need electricity (most of which is still produced by
fossil fuel sources in the UK) to extract it from water, and in most methods, an
additional fuel source such as natural gas. Powering the UK’s vehicles with hydrogen
would more than double the country’s current electricity consumption 24 . It is likely
that any big expansion of hydrogen power would have to rely on mostly fossil fuel
power for the foreseeable future. According to some people ‘producing the hydrogen
and compressing or liquefying it to use as a vehicle fuel could have a worse impact on
the climate than using petrol’ 25 .
On the other hand, hydrogen-powered fuel cells produce no pollution on the roads –
the only by-product is water vapour. Therefore it has been seen as a useful option for
cities and also with H&S benefits, and introduced onto some London buses by Ken
Livingstone. Public procurement and significant EU and US funding has sought to
drive this technology.
For a number of years vehicle manufacturers have claimed that hydrogen powered
vehicles are only a few years away from mass production – but they have been saying
this for quite a long time! The technology remains very expensive as it dependent on
precious materials such as platinum and on difficult processes. Safety is a concern, as
hydrogen leaks and ignites easily and invisibly. The market has also been held back
by doubts whether the necessary infrastructure (eg hydrogen filling stations and
distribution networks) is likely to appear. Therefore, in the last couple of years car
manufacturers have appeared to move away from hydrogen and back towards the idea
of electric vehicles.
23 Greenpeace International – Cooking the Climate, November 2007
24 Decarbonising the UK - Tyndall Centre for Climate Change Research
25 Techno-fixes – A Critical Guide to Climate Change Technologies, Corporate Watch, 2008
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