(CNN) – European transportation officials are using words like "unprecedented" and "unsustainable" when describing air travel across the continent.
That's just the short-term view. There's a very real threat of more eruptions in Iceland. To help us understand how unpredictable the situation is, we spoke with R.B. Trombley on Monday's American Morning. He is the lead volcanologist and director of the International Volcano Research Center.