A major conundrum in climate science is how to account for dependence between climate models. This complicates interpretation of probabilistic projections derived from such models. Here we show that this problem can be addressed using a novel method to test multiple non-exclusive hypotheses, and to make predictions under such hypotheses. We apply the method to probabilistically estimate the level of global warming needed for a September ice-free Arctic, using an ensemble of historical and representative concentration pathway 8.5 emissions scenario climate model runs. We show that not accounting for model dependence can lead to biased projections. Incorporating more constraints on models may minimize the impact of neglecting model non-exclusivity. Most likely, September Arctic sea ice will effectively disappear at between approximately 2 and 2.5 K of global warming. Yet, limiting the warming to 1.5 K under the Paris agreement may not be sufficient to prevent the ice-free Arctic.
1.Yonsei Univ, Dept Atmospher Sci, Seoul 03722, South Korea 2.Inst Basic Sci, Ctr Climate Phys, Tonghapgigyegwan Bldg,Busandaehak Ro 63 Beon Gil, Busan 46241, South Korea 3.Pusan Natl Univ, Busan 46241, South Korea 4.UNSW Australia, Sch Math & Stat, Red Ctr, Room 2055, Sydney, NSW 2052, Australia 5.Univ Cincinnati, Dept Math Sci, Div Stat & Data Sci, 5516 French Hall,2815 Commons Way, Cincinnati, OH 45221 USA 6.UNSW Australia, Climate Change Res Ctr, 4th Level Mathews Bldg, Sydney, NSW 2052, Australia 7.UNSW Australia, Arc Ctr Excellence Climate Extremes, 4th Level Mathews Bldg, Sydney, NSW 2052, Australia 8.Pusan Natl Univ, Res Ctr Climate Sci, Room 1113,Tonghapgigyegwan Bldg,Busandaehak Ro 63, Busan 46241, South Korea
Recommended Citation:
Olson, R.,An, S-, I,Fan, Y.,et al. A novel method to test non-exclusive hypotheses applied to Arctic ice projections from dependent models[J]. NATURE COMMUNICATIONS,2019-01-01,10