With the length and intensity of a volcano’s eruption nearly impossible to predict, experts are unsure of how costly Iceland’s Eyjafjallajokull volcano eruption will be to the European economy. With thousands of flights canceled until Monday, businessmen and diplomats are stranded around the world. (When German Chancellor Angela Merkel left the U.S., she had to fly to Lisbon, then Rome, overnighted in northern Italy, and planned to take a bus home.) Airlines are losing about $200 million a day; next week could see $1 billion in losses—a huge blow as the industry was just beginning to recover from the global financial crisis. Produce can’t get to supermarkets, and if the volcano continues to spew ash much longer, there could be shortages as food spoils. Supplies to troops in Afghanistan had to be rerouted, as were flights taking the most severely injured soldiers to Germany for treatment. The World Health Organization says the ash poses little health risk, though people with asthma were encouraged to stay indoors in Britain. Eyjafjallajokull shows no sign of abating, and could last for months.