Just north of here, on the far side of the impenetrable Vatnajokull ice sheet, lava is spewing from a crack in the earth on the flanks of Bardarbunga, one of Iceland’s largest volcanoes. By volcanologists’ standards, it is a peaceful eruption, the lava merely spreading across the landscape as gases bubble out of it. For now, those gases — especially sulfur dioxide, which can cause respiratory and other problems — MORE