Actually it seems there were 17 authors not 16. It is not easy to judge this. Their paper is very long and detailed and rests on 3 legs: 1. the "Eemian": last period when climate was warmer than now, 118 kyr ago, when they claim based on paleo/geological evidence collected in a large number of other papers all over the world, that there were large rapid sea level rises and falls, huge waves, and superstorms. 2. running computer climate models with a few new effects added that cause positive feedbacks and hence exponential "doubling time" behaviors of, e.g. ice sheet melt rates. There are some obvious positive feedbacks like more sheet melt ==> darker earth surface ==> more warming, with the rate increasing exponentially, the more ice has melted, the faster it melts. There also are some non-obvious feedbacks such as the impact if fresh meltwater on ocean currents driven by salinity differences. 3. contemporary measurements of stuff like ice sheet melt rates, sea level, and ice sheet cover from satellite photos, radar, and gravity measurements, which is used to justify the alterations in the computer models. For example, the old models (they say) had too much vertical ocean mixing. If that is reduced, then the surface waters get warmer faster than in the old models, causing more storms and more ice to melt. They think during the Eemian there was 2-3 meter sea rise, than a 2-3 meter fall, then a 6-9 meter rise. Wikipedia says the Eemian was 130 to 115 kyr ago. https://en.wikipedia.org/wiki/Eemian They believe these changes each took less than 500 years, maybe only 100. I doubt it is possible to reach their level of confidence without basically becoming a climatologist yourself, and one specializing in their topics, and maybe not even then since it took 17 authors. -- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)