| 18 Nov 2025
Temperature and radiative responses to anthropogenic aerosols over the Mediterranean Basin based on CMIP6 Earth system models
Abstract. Here, we assess the amplification of near-surface warming in the Mediterranean (MED) resulting from global anthropogenic aerosol (AA) reductions, based on simulations from CMIP6 Earth system models (ESMs). Temperature and radiative responses are investigated over the MED. The effective radiative forcing (ERF) and near-surface temperature (TAS) exhibit decreasing trends until around 1980 followed by increasing trends, driven by air pollution control policies. The annual mean ERF at the top-of-atmosphere over the MED changes by 2.37±1.06 W m-2 between the peak AA period (1970–1979) and the near-present period (2005–2014). During this interval, the annual mean TAS increases by 0.67±0.37 °C. Overall, the multi-model ensemble shows a robust amplification of warming over the MED on annual scale resulting from global AA reductions from 1970–1979 to 2005–2014, in good agreement with observational datasets over land. The model simulations indicate that AAs are responsible for 49 % (39 %) of the annual (summer) warming between the two periods. In the winter, ESMs produce an overestimated warming of 1.19 °C, with AAs contributing 60 % to this warming. Finally, we show that circulation changes caused by AA reductions can play an additional role in the redistribution of regional temperature changes apart from the radiative effects per se. Our results reveal a strong link between the recent acceleration of MED warming and global AA decreases, which unmask additional greenhouse gas-driven warming. This study highlights the sensitivity of the MED to global emission changes and the need for climate policies that couple air quality improvements with rapid greenhouse gas mitigation.
This is a quite focused paper about changes in aerosol optical depth, effective radiative forcing and atmospheric radiative cooling at the surface. The area investigated is the Mediterranean region and, although the historical period extended from 1850 to 2014, two specific periods, 1970-1979 and 2005-2014 and two seasons, winter and summer, were investigated. Since the paper considers differences between historical and hist-piAer simulations from the CMIP6 Earth system models, this manuscript is developed for specialised readers. Although the work done is noticeable, perhaps some minor changes should be introduced to improve the manuscript.
The authors should think about procedures to increase the number of potential readers. Perhaps the authors should highlight the reasons for the selected region and they should underline if the procedure could be applied in different areas and they should compare the obtained results with those calculated for other regions.
The authors consider the regions with impact on the Mediterranean basin. However, they should indicate the regions beyond Europe influenced by the studied area.
Monthly outputs were used. This period ignores short-term changes and the authors should value if these changes could be noticeable or not.
The authors consider two ten-year periods, 1970-1979 and 2005-2014 where a noticeable change of human activity is expected. However, they should indicate if both periods are similar from a meteorological point of view or not, since the atmosphere response depends on both, natural and human processes.
The main inconvenience is the lack of references in the results section to compare this analysis with previous studies. Perhaps some references could be transferred from other sections to discuss the results or some new references could be introduced.