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The problem with
flying is two fold: firstly it may only give out as much
CO2 per km than a car but you go MUCH further in planes
than you do in cars. Secondly, the higher you fly the more
the green house gas effect from your aviation emissions is
magnified. One flight across the Atlantic uses more fuel
than the average car driver gets through in fifty years.
Emissions such as nitrous oxide and water are virulent
GHG's. The water vapour forms cirrus cloud that traps in
planetary heat. This, combined with oxides of sulphur and
nitrogen, makes the emissions 2.7 times more
dangerous than the same emissions at ground level. Air
traffic increases at 5% a year.
What is more
there is no alternative to fossil fuels to keep those
Boeings and Airbuses in the air. Hydrogen is cleaner but the
fuel tanks would be four times the size hence displacing the
passenger seats! What is more the Hydrogen burns to form
even more water vapour. So it might be renewable but it
won't reduce GHG emissions to zero. Bio-fuel ethanol is far
heavier than regular aviation fuel and more is required to
produce the same engine thrust. It's energy density is much
lower. Even worse it has a much higher freezing temperature
meaning that, at high altitude it is wax and useless in a
modern jet engine. All that ignores the mounting evidence
that it actually takes as much fossil fuel to produce
bio-fuels than it yields in bio-fuel. Hence this process is
not self-sustaining nor does it reduce GHG emissions where
ancient forest has been cleared to grow the bio-fuel crops.
An all round disaster.
Offsetting? A
non-starter. Post-Carbon Living only recommend investing in
carbon sequestration (amongst other ethical investments)
when you have already stopped flying altogether. As we
learnt earlier, deforestation is contributing 18% of the
Climate Change problem hence reforestation is a really good
idea - but it is not an excuse to fly and it certainly isn't
guaranteed to consume your carbon emissions from flying
sometime soon. It might take 60 years whilst climate change
is here and now. We can't wait that long so those fossil
fuels really need to stay in the ground whilst, at the
same time, investing in forests and other good carbon
sinks where they don't displace agriculture.
Where does that
leave us? Small propeller driven planes are less damaging
but only on regional flights where you are better off taking
a train. Trains emit 8 times less CO2 per passenger mile
than a plane although that does depend on how fast you go.
Indeed, the slower the better. Ideally electricity for such
railways must be produced from renewable source otherwise
you are only displacing the problem to your nearest fossil
fuel-fired power station. What about ships? The arguments
differ - obviously sailing vessels are very CO2-neutral but
not if you want to go anywhere in a hurry. Evidence from one
source suggest that ships are twice as bad as planes because
of the low grade bunker fuel they use.
To offset
aviation emissions from the UK the rest of the economy would
have to reduce their emissions by up to 87%. Even that
doesn't go far enough with many campaigners suggesting that
aviation-related CO2 emissions growth in the UK likely to
outstrip the rest of the economy if we are to reduce our
Carbon footprint to just 90% of where we are today. Flying
was excluded from the Kyoto Protocol because it is political
dynamite wrapped up in thousands of bi-lateral agreements
meaning that no country can tax aviation fuel uni-laterally.
There has to be international consensus and action.
Until then, in
short, stop flying. |
