The climate change effects of Eyjafjallajökull

Several people have sent me the graphic below which tries to assess the pros and cons of the Icelandic eruption in terms of CO2. However it doesn’t reflect what’s really happening because to get the true greenhouse effect you have to multiply the CO2/NO2 emitted by planes by 2.7 to account for their water vapour trails which act as a greenhouse gas. So the big red triangle should be about three times bigger.

Also the sulphur being spewed out from the volcano is having a cooling effect. Sulphur combines with water vapor in the stratosphere to form dense clouds of tiny sulfuric acid droplets which absorb solar radiation and scatter it back to space.

Mount Pinatubo in the Philippines erupted on 15th June 1991, followed one month later by Mount Hudson in southern Chile. The Pinatubo eruption produced the largest sulphur oxide cloud of the 20th century. The combined aerosol plume from the two eruptions spread around the planet. The data collected after these eruptions show that mean global temperatures decreased by about 1°C over the next two years.