Multi-model assessment of the next-decade climate over the Mediterranean region

<p>The Mediterranean region is one of the most sensitive to climate change since it has undergone an intense warming and drying trend during the last decades, dominantly caused by the increase of anthropogenic greenhouse gases&#8217; concentrations. In the context of decision-making processes, there is a growing interest in understanding the near-term climate evolution of this region.<br />In this study, we explore the climatic fluctuations of the Mediterranean region in the near-term range using two different products: projections and decadal predictions. The former are century-scale climate change simulations initialized from arbitrary model states to which were applied anthropogenic and natural forcings. A major limitation of climate projections is their limited information regarding the current state of the Earth&#8217;s climate system. Decadal climate predictions, obtained by constraining the initial conditions of an ensemble of model simulations through a best estimate of the observed climate state, provide a better understanding of the next-decade climate (typically up to 10 years) and thus an invaluable tool in assisting climate adaptation.<br />Using forecasts from several decadal prediction systems &#8212; performed within the CMIP6 Decadal Climate Prediction Project (CMIP6 DCPP) &#8212; and the respective ensemble of non-initialized projections, we evaluate future climate changes of the Mediterranean region for some key quantities so as to assess the added value of initialization. Beyond the contribution of external forcings, the role of internal variability is also investigated since part of the detected predictability arises from internal climate variability patterns affecting the Mediterranean by atmospheric teleconnections.</p>