Global warming-induced changes in climate zones based on CMIP5 projections

Abstract

Climate classifications can provide an effective tool for integrated assessment of climate model results. We present an analysis of future global climate projections performed in the framework of the Coupled Model Intercomparison Project Phase 5 (CMIP5) project by means of Köppen-Trewartha classification. Maps of future climate type distributions were created along with the analysis of the ensemble spread. The simulations under scenarios with representative concentration pathway (RCP) 4.5 and RCP8.5 showed a substantial decline in ice cap, tundra, and boreal climate in the warming world, accompanied by an expansion of temperate climates, dry climates, and savanna, nearly unanimous within the CMIP5 ensemble. Results for the subtropical climate types were generally not conclusive. Changes in climate zones were also analyzed in comparison with the individual model performance for the historical period 1961-1990. The magnitude of change was higher than model errors only for tundra, boreal, and temperate continental climate types. For other types, the response was mostly smaller than model error, or there was considerable disagreement among the ensemble members. Altogether, around 14% of the continental area is expected to change climate types by the end of the 21st century under the projected RCP4.5 forcing and 20% under the RCP8.5 scenario.