Attribution of pre-selected climate indicators in summer over the Carpathian basin

While anthropogenic global warming is well-accepted and thoroughly described in the climate community, the vast majority of the general public is still not always fully-certain whether to associate specific local weather or climate event with this global phenomenon. It is of utmost importance to raise public awareness by providing easily understood but scientifically sound information, and to explain how the anthropogenic activity contributes to specific weather or climate events. Although it is getting to be widely assessed now in Western Europe, only a few case studies for past high-impact local weather events were assessed in Hungary, and the systematic analyses of long-term trends of such indicators with their linkage to anthropogenic activity are missing in this region. Our local attribution project (started in September 2021) aims to fill this gap in Hungary: the results of the analyses of seasonally relevant indices are published in each season at around a time of an event occurrence or absence. Dissemination is executed via an already established, online Hungarian platform (https://masfelfok.hu/, meaning “1.5 degrees”), since it is reaching the general public with its readily understood climate change information through its broad media coverage and a growing social media network.

The analysis uses several freely-available data sets: (1) an ensemble selection of CMIP6 global climate model simulations with both natural-only forcings and historical runs, (2) a fit-for-purpose ensemble of regional climate model simulations from the Euro-CORDEX on 0.11° resolution, including the RCP2.6, RCP4.5 and RCP8.5 future scenarios, (3) a fine-resolution, homogenized observation-based gridded data for Hungary, compiled by the Hungarian Meteorological Service, (4) the newest E-OBS database for the area outside of Hungary. Within the project, we selected seasonally relevant extreme, less extreme but well-known events, and these pre-selected indices are attributed to anthropogenic activity through their detected intensity, duration, or frequency changes. For instance, third-level heatwave days, hot days, tropical nights, annual temperature maxima and return values, meteorological droughts, and heavy precipitation days are evaluated for summer, as they have the largest public interest and impacts in our target region.