This is firmly in the 'Two wrong's do not...' camp, but I would like to know*:
Do you think the BBC environment correspondent will tell us how much CO2 and sulfur compounds has been released by the Tongan volcano in the last two days, and what % this represents of the sum of similar gases released by annual human industrial activity?
This may bring up an 'inconvenient' fact or two.
It becomes pertinent as one discusses the relative man-worsened aspects of anthropomorphic climate change. I wonder if we will get any discussion, much less answers, from some usual suspects quitekeen on rushing to print and screen with other data when it suits?
Times - Underwater volcano sends huge columns of ash into Pacific sky
Indy - Volcano shatters Pacific calm around Tonga
ADDENDUM
*I asked; I may have an answer (if from another source, and an unvetted one for now. And I await, with dread, the publishing of equally valid-looking data that claims the exact opposite) in another blog...
48. At 8:58pm on 21 Mar 2009, manysummits
We have injected a trillion (1 x 10 EEX 12) metric tons of CO2 into the atmosphere since 1751, half of that in the last twenty five years, and we are increasing that by some two to three percent per year. Background volcanic emmisions from all volcanoes, including the 60,000 kilometer mid-ocean ridge system, are on the order of 0.2 to at most 1 billion (1 x 10 EEX 9) tons per year, two orders of magnitude less than we, anthropogens all, are emitting per year.
CO2 is up 38 percent over preindustrial levels (280 to 387 ppmv), and has never been above 300 ppmv for at least 450,000 years (four glacial intergalcial cycles).
The search continues.
ADDENDUM 23/03/09 - Alaskan volcano Mount Redoubt erupts -
2 comments:
As I was a geologist, at least by academic training, in my youth, this topic has always been of interest to me. Years back I had always assumed that volcanoes emitted far more CO2, sulphur etc. than they actually do, at least if you don't count super eruptions (Krakatoa was probably the most recent that could be classified as such). I was wrong back then and am still to this day surprised that volcanic emissions are as low as the scientists still calculate.
Having done a quick bit of googling, it seems that man's CO2 emissions are indeed very significantly higher than volcanic emissions, at least in terms of our planets more recent geological history. The section below is clipped from the USGS website -
page link here.
(click on the 'Effects' tab).
Clip starts.....
Comparison of CO2 emissions from volcanoes vs. human activities.
Scientists have calculated that volcanoes emit between about 130-230 million tonnes (145-255 million tons) of CO2 into the atmosphere every year (Gerlach, 1999, 1991). This estimate includes both subaerial and submarine volcanoes, about in equal amounts. Emissions of CO2 by human activities, including fossil fuel burning, cement production, and gas flaring, amount to about 27 billion tonnes per year (30 billion tons) [ ( Marland, et al., 2006) - The reference gives the amount of released carbon (C), rather than CO2, through 2003.]. Human activities release more than 130 times the amount of CO2 emitted by volcanoes--the equivalent of more than 8,000 additional volcanoes like Kilauea (Kilauea emits about 3.3 million tonnes/year)! (Gerlach et. al., 2002).
Clip ends.
I don't think there will be too many people out there who could argue with, disagree and/or try to refute data such as this with the USGS.
Also of interest is that although volcanic eruptions do indeed put significant amounts of greenhouse gases into the atmosphere (both CO2 and Methane), they also throw millions of tonnes of sulphur into the upper atmosphere. This decays into sulphuric acid aerosols which actually reflect the suns radiation quite effectively and lead to a temporary cooling effect on our little lump of planetary rock.
"the large explosive eruption of Mount Pinatubo on 15 June 1991 expelled 3-5 km3 of dacite magma and injected about 17 million tonnes of SO2 into the stratosphere. The sulfur aerosols resulted in a 0.5-0.6°C cooling of the Earth's surface in the Northern Hemisphere."
(Also from the USGS website.)
Ain't our little planet and its climate dammed complicated!!
Oh, wow. This is when this blog gives me a big fat grin.
Thank you for a most eloquent, factual, objective and well-linked explanation that certainly advances my knowledge base!
I cert for the next newsletter...when I get time!
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