The Earth seems to have been smoking a lot recently. Volcanoes are currently erupting in Iceland, Hawaii, Indonesia, and Mexico. Others, in the Philippines and Papua New Guinea, erupted recently but seem to have calmed down. And then there was the fatal eruption in Japan. Many of these have threatened homes and forced evacuations. But among their less-endangered spectators, these eruptions may have raised a question: Is there such a thing as a season for volcanic eruptions? Surprisingly, this may be a possibility. While volcano “seasons” aren't anything like the four we're familiar with, scientists have started to discern intriguing patterns in their activity. Eruptions caused by climate change In recent decades, it has become apparent that the consequences of planetary ice loss might not end with rising sea levels. Evidence has been building that in the past, periods of severe loss of glaciers were followed by a significant spike in volcanic activity. Around 19,000 years ago, glaciation was at a peak, and much of Europe and North America was under ice. Then the climate warmed, and the glaciers began to recede. The effect on the planet was generally quite favourable for humankind. But, since the mid-1970s, a number of studies have suggested that, as the ice vanished, volcanic eruptions became much more frequent. A 2009 study, for example, concluded that between 12,000 and 7,000 years ago, the global level of volcanic activity rose by up to six times. During roughly the same period the rate of volcanic activity in Iceland soared to at least 30 times today’s level. There is supporting evidence from continental Europe, North America and Antarctica that volcanic activity also increased after earlier deglaciation cycles. Bizarrely, then, volcanic activity seems—at least sometimes—to rise and fall with ice levels. But why? Again, this strange effect might be down to stress. More via Ars Technica.