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Volcanic ash particles are not like burglars: linear dose dependent.

John Brockman’s Edge site has lots of short essay-lets on what the ash cloud
episode means
. Maybe because of the way it was reported in the
USA, remarkably few of the commentaries seem to get that it was a
huge buearucratic over-reaction to a theoretical model and based on
a zero-tolerance approach to ash that makes no sense. And it caused
real economic and emtoional pain.

No coincidence that the models were built for radioactivity.
Ash, chemicals, fallout and heat are things which are not linear in
their risk. That is to say, a very low dose is not slightly more
dangerous than no dose. It’s no more dangerous. This is not true of
burglars and smallpox viruses.

Here’s my contribution to the Edge collection:

The ash cloud reminds us of the risks of
risk aversion. Shutting down Europe’s airspace removed the risk of
an ash-caused crash, but it also increased all sorts of other
risks: the risk of death to a patient because an urgent medical
operation might have to be postponed for lack of supplies, the risk
of poverty to a Kenyan farm worker because roses could not be flown
to European markets, the risk of a collision between ferries on
extra night-time sailings in the English Channel. And so on. Risk
decisions cannot be taken in isolation. The precautionary principle
makes too little allowance for the risks that are run by avoiding
risks – the innovations not made, the existing suffering not
alleviated. The ash cloud, by reminding us of the risks of not
being able to fly planes, is a timely reminder that the risks of
global warming must be weighed against the risks of high energy
costs – the risks of poverty (cheap energy creates jobs), of hunger
(fertiliser costs depend on energy costs), of rainforest
destruction and indoor air pollution (expensive electricity makes
firewood seem cheaper), of orangutan extinction in subsidised
biofuel palm oil plantations.

Oh, and remember the lessons of
public choice theory: if you set up a body called the Volcanic Ash
Advisory Centre, don’t be surprised if it over-reacts the first
time it gets a chance the demonstrate that it considers itself – as
all public bodies always do – underfunded.

Update: See Brendan O’Neill’s hilarious skewering ot the
intelligentsia’s moralistic reaction to the ash cloud:

…the excitable idea that one volcanic
belch has reminded us how small we are reveals what lies behind the
contemporary green outlook: a misanthropic view of mankind as a
cocky and destructive species which needs to be firmly put back in
its place. It is striking that even a natural event which cannot in
anyway be described as ‘manmade’ has unleashed so much
nature-dominates-man commentary. This shows that, for all
contemporary commentators’ claims that they are only interested in
communicating the ‘scientific facts’ about what will happen if we
continue distorting and warping the natural world with CO2, in fact
they are instinctively drawn to any natural occurrence that can be
held up as evidence of Mother Nature’s power over deluded


By Matt Ridley | Tagged:  rational-optimist