Iceland volcano gives warming world chance to debunk climate sceptic myths

21.4.2010 (Guardian)

Climate sceptics’ favourite theory that volcanoes produce more CO2 than human
activity has exploded in their faces with Eyjafjallajokull eruption

Along with the ash and lava, there have been many interesting asides tossed into
the air for our consideration by the
Eyjafjallajokull volcano.   We have noticed just how reliant our globalised systems are on air travel.   We have been reminded of nature’s brute force and primordial
beauty. And we have been intrigued by what a wonderfully complex language
Icelandic appears to be – to Anglo-Saxon ears, at least.


But one opportunity the volcano has gifted us in particular is the chance to
put to bed once and for all that barrel-aged climate sceptic canard which maintains
that volcanoes emit far more carbon dioxide than anthropogenic sources. It’s always
been a favourite, but has been pushed even further up the charts of popularity
in recent months by
the repeated claims of Ian Plimer, the Australian mining geologist who wrote the climate sceptic bible Heaven
and Earth last year.


Here, for example, is what Plimer wrote on Australia’s ABC Network website last August:



The atmosphere contains only 0.001 per cent of all carbon at the surface of the
Earth and far greater quantities are present in the lower crust and mantle of
the Earth. Human additions of CO2 to the atmosphere must be taken into perspective.
Over the past 250 years, humans have added just one part of CO2 in 10,000 to the
atmosphere. One volcanic cough can do this in a day.



John Cook of the increasingly popular Skeptical Science website currently lists the “volcanoes emit more CO2 than humans” viewpoint as number 54 on his ever-growing list – 107, to date – of debunked sceptic arguments.


It was also a point picked up by my colleague James Randerson when he interviewed Plimer last December.   In Heaven and Earth, Plimer says: “Volcanoes produce more CO2
than the world’s cars and industries combined.” Randerson challenged Plimer on
this point, stating that the 
US Geological Survey (USGS) states: “Human activities release more than 130 times the amount of CO2 emitted by


Plimer responded by saying that this does not account for undersea eruptions.
However, when Randerson checked this point with USGS volcanologist Dr Terrence
Gerlach, he received this reply:



I can confirm to you that the “130 times” figure on the USGS website is an estimate
that includes all volcanoes – submarine as well as subaerial … Geoscientists
have two methods for estimating the CO2 output of the mid-oceanic ridges. There
were estimates for the CO2 output of the mid-oceanic ridges before there were
estimates for the global output of subaerial volcanoes.



Despite having seemingly lanced this festering boil for good, the focus on Eyjafjallajokull
over the past week has allowed this question to bubble back up to the forefront
of people’s minds. It was enough to trigger the Paris-based AFP news agency
to seek some answers:



Iceland‘s Eyjafjoell volcano is emitting between 150,000 and 300,000 tonnes of carbon
dioxide (CO2) per day, a figure placing it in the same emissions league as a small-to-medium
European economy, experts said on Monday.

Assuming the composition of gas to be the same as in an earlier eruption on an
adjacent volcano, “the CO2 flux of Eyjafjoell would be 150,000 tonnes per day,”
Colin Macpherson, an Earth scientist at Britain’s University of Durham, said in
an email.

Patrick Allard of the Paris Institute for Global Physics (IPGP) gave what he
described as a “top-range” estimate of 300,000 tonnes per day.

Both insisted that these were only approximate estimates.

Extrapolated over a year, the emissions would place the volcano 47th to 75th
in the world table of emitters on a country-by-country basis, according to a database
at the World Resources Institute (WRI), which tracks environment and sustainable

A 47th ranking would place it above Austria, Belarus, Portugal, Ireland, Finland,
Bulgaria, Sweden, Denmark and Switzerland, according to this list, which relates
to 2005.

Experts stressed that the [ Eyjafjallajokull ]  volcano contributed just a tiny
amount – less than 0.3% – of global emissions of greenhouse gases.



So, please, can we now put this hoary old chestnut to bed?


One extra volcano-related aside: with European carbon market prices fluctuating
around the €14 per tonne mark
at present, this would mean that Eyjafjallajokull would theoretically be liable to a maximum
daily bill of €4.2m if it were a fully fledged, carbon-trading nation or corporation.
But who would dare get close enough to present it with an invoice?