Sea level is rising more slowly than expected, and the rise is slowing down rather than speeding up. Sea level rise is the greatest potential threat to civilization posed by climate change because so many of us live near the coast. Yet, at a foot a century and slowing, it is a slight nosebleed. So are most of the other symptoms of climate change, such as Arctic sea ice retreat, in terms of their impact. The rate of increase of temperature (0.6C in 50 years) is not on track to do net harm (which most experts say is 2C) by the end of this century.