New Scientist: ONE climate domino has fallen, and it may start toppling others. A recent study outlined an interconnected web of climate tipping points, some of which make the next ones more likely. Now, an analysis of data from the last 23 years suggests we passed the first of these tipping points in 2007, when Arctic sea ice flipped into a new, less stable state. That may speed the world towards the next tipping point the thaw of a vast expanse of Siberian permafrost. When it comes to the consequences of climate...