Bit of an exaggeration to say that it brought Europe to a standstill.

In reality it hardly made the slightest difference considering that the total economy of Europe is about US$18 trillion (GDP price parity to US). So your $2 billion* works out to about one hour of lost production over the year, ie: it is barely noticeable. Admittedly this $18 trillion is for the whole of Europe, including the Eastern Europe countries that were not affected. The economy of just the EU countries is about US$14.7 trillion- so $2billion is less than 75 minutes of the EU's economy. Even if you take the extreme position that the $2billion loss was carried solely by the UK then it works out at about 8 hours of lost UK production- which over the 8760 hours of the whole year is still not much.

Nor did the airspace closure make much of a dent in the total number of commutes or miles/person traveled a day in Europe. The average total number of daily transport movements in Europe for a given day is in the billions. Planes make up only a very small percentage when compared to walking, automobiles, trains and boats.

*Not sure which currency you're referring to so I'll assume $US

The world was not brought to a stop by a volcano. The world was brought to a stop by kneejerking office wallahs who should now be made repay airlines and travellers compensation for the inconvenience they caused and the economic losses they inflicted.

These are the same sort of alarmists who brought us the great global warming con.

It's the very same climate modellers, who have given us the global warming fiasco, who gave us another stuff up.

Perhaps they are annoyed that the world has finally seen through their scam, & decided to get one back with this stupidity.

At least it was probably worth it, to finally bring home to most, just how incompetent these people really are.