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An attempt to deconstruct recent climate change in the Baltic Sea basin
Author(s) -
Barkhordarian A.,
Storch H.,
Zorita E.,
GómezNavarro J. J.
Publication year - 2016
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2015jd024648
Subject(s) - greenhouse gas , climatology , forcing (mathematics) , climate change , precipitation , environmental science , climate model , baltic sea , structural basin , global warming , radiative forcing , climate commitment , range (aeronautics) , natural (archaeology) , atmospheric sciences , effects of global warming , geography , oceanography , meteorology , geology , paleontology , materials science , archaeology , composite material
Abstract We investigate whether the recently observed temperature and precipitation trends over the Baltic Sea Basin are consistent with state‐of‐the‐art regional climate model projections. To address this question we use several data sources: (1) multidecadal trends derived from various observational data sets, (2) estimates of natural variability provided by a 2000 year paleoclimatic model simulation, and (3) response to greenhouse gas forcing derived from regional climate simulations driven by the A1B and RCP4.5 scenarios (from ENSEMBLES and CORDEX projects). Results indicate that, over the past decades, the climate in the Baltic Sea Basin has undergone a change that is beyond the estimated range of natural variability. We test the hypothesis that this change may be understood as a manifestation of global warming due to increasing concentrations of greenhouse gases (GHGs). We find that changes in near‐surface temperature support our hypothesis that the effect of GHG is needed to simulate the observed changes. The pattern correlation and regression results clearly illustrate the concerted emergence of an anthropogenic signal consistent with the GHG signal in summer and autumn in the 21st century. However, none of the 19 regional climate simulations used in this study reproduce the observed warming. The observed trends in precipitation and surface solar radiation are also partially inconsistent with the expected changes due to GHG forcing. We conclude that, besides the regional response to GHG forcing, other human‐made drivers have had an imprint. Regional emission of industrial aerosols has been strongly reduced in this region, and we suggest that this reduction may be the missing driver.