Montreal Gazette: In the summer of 2007, a large portion of Arctic Sea ice – about 40 per cent – simply vanished. That wasn’t supposed to happen. At least not yet. As recent as 2004, scientists had predicted it would take another 50 to 100 years for that much ice to melt. Yet here it was happening today. It raised the question: Had global warming suddenly pressed the gas pedal to the floor? If so, the world was in for quite a climate ride – dramatic, jarring changes in climate much sooner than …