Ocean and atmosphere changes in the Caribbean Sea during the twenty-first century using CMIP5 models

Coastal communities around the Caribbean Sea are vulnerable to global warming impacts, partly because of constraints on their adaptive capacity. We use three climate models provided by the Coupled Model Intercomparison Project Phase 5 (CMIP5) under two representative concentration pathways scenario (RCP4.5 and RCP8.5) to assess the trends and spatial behavior of six atmospheric and ocean variables in the Caribbean Basin during the twenty-first century. Atmospheric results are reported from the model ensemble; however oceanic results are reported from ACCESS1.0 model, as its resolution captures mesoscale processes which are important for regional sea level projections. Surface atmospheric pressure and wind do not show significant trends. On the contrary, air and sea surface temperature, surface salinity, and mean sterodynamic sea level have coherent positive trends in the Caribbean Basin, which increase with a greater RCP scenario. Air temperature will probably increase by 2 °C over the preindustrial period during the century. Moreover, sea surface temperature is expected to rise between 1.92° and 3.01 °C in the 1976–2005 to 2071–2100 period. The Caribbean Sea warming will have the potential to extend the hurricane season, increase the frequency of tropical storms, and intensify coral bleaching events. In the same period, mean sterodynamic sea level is expected to rise in the basin between 32.53 and 43.25 cm, depending on the RCP scenario used. The strongest trend expected in 2005-2100 is 50.84 ± 1.48 cm cy − 1 under RCP8.5 scenario. Furthermore, the trends appear to accelerate since the last century in the basin. Besides, sterodynamic sea level rise would account for slightly over half of the total sea level rise in the Caribbean, after land-ice melting among other contributions not accounted by CMIP5 models are included. These trends have the potential to exacerbate flooding and erosion, putting at risk coastal areas, including low-elevation islands such as some in the San Andres and Providencia Archipelago.