As an Icelandic Volcano reduces the Western European Space-Time Continuum to around 1900 standards, the environmental impact is another thing to consider. Here, at "Information is Beautiful" they have created a diagram contrasting CO2 emissions of the Volcano vs. the potential release of CO2 were flights not grounded in Europe (which accounts for approximately 30% of world air-travel). Pretty interesting. They keep updating the chart as information becomes available. Click HERE for the actual website.