I thought I'd make my first post about the event that
inspired this blog. In April 2010 the Eyjafjallajökull Volcano in Iceland erupted, spewing millions of tonnes of
ash into the air. The ensuing ash cloud which engulfed northern Europe forced
twenty countries to close their airspace, grounding hundreds of thousands of
flights.
What was bad news
for tourists was a once in a lifetime opportunity for scientists. Previously
they could only postulate the effects of such a large scale change to aviation
– now they could observe it firsthand.
David McCandless produced this marvelous diagram for his information is
beautiful website to illustrate the
carbon dioxide offset by all those grounded flights. He references his sources
here.
Let's take the
idea one step further. Instead of European flights, what would be the impact of
grounding all the flights in the world? (on a side note, the video below- an animation of all the flights in the world - makes fascinating viewing).
Each year, 165
member countries report their greenhouse gas emissions the United Nations
Framework Convention on Climate Change. The World Resources Institute (WRI), a
global environmental think tank, compile this data to produce a comprehensive
database of global emissions. According to the WRI, 1.6% of global greenhouse gas
emissions are from aviation. So the impact of not flying would be
relatively small right?
Not quite.
Aviation emissions have a threefold effect. Firstly, there's the direct emissions.
Next, the high concentrations of nitrous oxides emitted by planes induce the
formation of ozone, another greenhouse gas, which causes further warming. Finally,
aircraft contrails - water vapour tracks drawn in their wake - are thought to
induce clouds which further enhance warming. Once these two additional effects
are taken into account, the IPCC estimates
aviation accounts for 3.5% of total global emissions.
It's still only 3.5% - so why all the fuss about aviation?
It's because of the rate at which aviation emissions are
increasing. The aviation industry has grown 9% year on year since 1960. So stop
aviation now and you'll be stubbing out a major future emissions source.
