Fakem:
Total lack of scientific approach
The closing down of European air space and airports is a dreadful knee-jerk reaction brought upon us all by politicians. There is no proper collection and processing of scientific data to support the measures.
Are air samples collected from the allegedly contaminated FLs at hourly (or, at least, regular) intervals? Obviously not, or we would have this data being released on an ongoing basis.
The people inflicting this chaos on us are, in fact, flying blind with all instruments turned off. Dreadful, absolutely dreadful.
1. The precautionary principle applies, especially to things that might involve life.
The Volcanic Ash is regarded as dangerous to aircraft UNTIL it is proved scientifically that the risk is insignificant NOT the other way around as you suggest.
2. Politicians do not shoot from the hip
they make decisions on the basis of ADVICE they receive from public servants. I would imagine that public servants, mindful of the precautionary principle, asked for scientific advice on the level of risk, and failing receiving a ringing endorsement from the appropriate engineers and scientists for opening the skies, they applied the precautionary principle themselves.
To put it another way:
I know your holiday plans are in tatters. There is nothing anyone can do about it until the evidence is in that indicates it's safe to fly.