Russia has identified as many as 430 giant 'gas bombs' which could explode forming massive craters in the Arctic - potentially disrupting energy supplies to Europe. So far, 17 large holes have formed since 2014 in the Yamal and Gydan peninsulas in Siberia due to vast methane eruptions in thawing permafrost. The latest crater exploded this summer and the phenomenon has been linked to climate change. But some experts have ...