Is There a Precipitation Decline in the Mediterranean Region? An Assessment Based on the Scientific Literatured

ABSTRACT We have compiled studies published since 1980 on annual precipitation trends in the Mediterranean region. The total number of publications reviewed amounts to 337 papers, sourced from various references, focusing exclusively on studies that have analysed observational series, both from meteorological stations and gridded databases. The goal is to provide a comprehensive overview of the available research and results regarding annual precipitation trends, rather than criticising the quality of the data, methods used, or interpretations made. In this context, we present a compilation of papers in which we select original excerpts from the abstract, main text, or conclusions related to annual precipitation trends, summarising each manuscript. We do not focus on seasonal or monthly trends in detail; however, to offer a broader understanding of the extreme spatial and temporal variability of total annual precipitation, we have included in the Supporting Information file a compendium of papers classified by trends at the monthly and seasonal scales. No generalised significant trends are identified across the entire basin. When a significant signal is found, it greatly depends on the length of the period, the specific selected period, and the region. Finally, we discuss some key unresolved issues that need to be addressed to improve future research.