2017/02/15 by Giovanni Sgubin, Didier Swingedouw, Sybren Drijfhout +2 · 9 citations
Earth and Planetary Sciences · Environmental Science · #Biology #Climate change #Climate model #Climate variability and models #Climatology #Coupled model intercomparison project #Environmental science #Geography #Geology #Geology and Paleoclimatology Research #Meteorology #Oceanographic and Atmospheric Processes #Oceanography #Stratification (seeds)
paper · pdf · doi:10.1038/ncomms14375
openalex publication_date 2017/02/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
Observations over the 20th century evidence no long-term warming in the subpolar North Atlantic (SPG). This region even experienced a rapid cooling around 1970, raising a debate over its potential reoccurrence. Here we assess the risk of future abrupt SPG cooling in 40 climate models from the fifth Coupled Model Intercomparison Project (CMIP5). Contrary to the long-term SPG warming trend evidenced by most of the models, 17.5% of the models (7/40) project a rapid SPG cooling, consistent with a collapse of the local deep-ocean convection. Uncertainty in projections is associated with the models' varying capability in simulating the present-day SPG stratification, whose realistic reproduction appears a necessary condition for the onset of a convection collapse. This event occurs in 45.5% of the 11 models best able to simulate the observed SPG stratification. Thus, due to systematic model biases, the CMIP5 ensemble as a whole underestimates the chance of future abrupt SPG cooling, entailing crucial implications for observation and adaptation policy.