Grímsvötn ash cloud causes flight disruptions (but Ryanair president says it doesn't exist)

The ash from the Grímsvötn eruption in Iceland has now made its way to the British Isles and over 200 flights have been delayed or cancelled due to the ash, mostly of which are in British airspace, although some flights to Scandinavian countries (and Greenland) have been effected as well. This number could climb to over 500 if the ash persists. However, the eruption appears to be waning (see below for more details), which might suggest any flight disruptions will be brief. The London VAAC models predict that ash will also start to reach the northernmost part of continental Europe soon as well, so some flights into northern Germany, the Low Countries and France might be problematic. However, I was a little stunned this morning to see that Ryanair president Michael O'Leary thinks there is

no ash hazard whatsoever