How Bad are Volcanoes? (Aug 2011)
How did you feel about the The Grimsvotn volcano eruption this Spring? Were you annoyed by the upset to your travel plans or were you awed by the breath-taking scale and uncontrollability of nature? And did you stop to wonder about the impact of the eruption on climate change?
Worldwide, the US Geological Survey says volcanoes produce about 200 million tonnes of carbon dioxide every year. That’s a fair amount. But it is well less than 1 per cent of what we humans emit going about our daily business. Blaming volcanoes for climate change is just another example of how we evade our responsibilities, under God, to care for the Earth.
The overall impact, however, is less than this because volcanoes also throw up ash and sulphur dioxide into the stratosphere that shades the earth from the sun and has a cooling effect. Mount Pinatubo’s eruption in 1991 cooled the planet by half a degree the following year, although over decades there will probably have been a warming effect.
With the recent Icelandic eruptions there is, of course, a further fact to consider. Although the eruptions of Eyjafjallajökull in 2010 emitted about 150 000 tonnes of carbon dioxide per day, the grounded European flights avoided about 344 000 tonnes of carbon dioxide per day.
It seems volcanoes are not so bad for the climate, particularly if they limit one of our our most carbon-polluting activity.