Boiling Mediterranean, Aeneas:“May 2022-May 2023:longest heat wave in 40 years"

Gianmaria Sannino:“We are only at the beginning of a broader process and we are faced with increasingly frequent signs of what is to come.”

ROME – New alarm for climate change: from May 2022 to May 2023 the Mediterranean suffered the longest heat wave ever recorded in the last 40 years with an increase of up to 4°C in sea temperatures and peaks above 23°C.The hardest hit part was the western basin.This is what emerges from the CAREHeat project, financed by the European Space Agency (ESA), in which Enea and Cnr (coordinator) participate for Italy, the results of which were published in the journal Environmental Research Letters.

CAREHeat's research activities began with the study of the heat wave that affected the Mediterranean Sea starting from the analysis of satellite data who were the first to detect the thermal anomaly, with values ​​much higher than the previous heat wave of 2003.The satellite information was then integrated with data from observations available in situ at the Lampedusa Climate Station, which represents the only outpost in Europe capable of providing information on the interactions between vegetation, atmosphere and ocean, both in carbon exchanges and in all the processes and energy exchanges that regulate the climate of the region.Furthermore, thanks to the use of cutting-edge modeling simulations and data processing systems, the researchers were able to characterize the anomaly that affected the period.

In particular, from detailed investigations into the role of the so-called 'atmospheric forcings'– like, for example, the wind in conditioning the ocean – it emerged that sea ​​surface temperature anomalies are closely related to the prevalence of anticyclonic conditions in the atmosphere;conditions which in the same period also caused severe droughts in the Mediterranean region.Analysis of these data indicates that vertical mixing of the sea caused by wind is primarily responsible for heat transport within marine waters and that these subsurface anomalies lasted for several months.Finally, from the comparison between the evolution of the 2022/23 event with the previous event of 2003, some aspects related to climate change in the region emerged:among these, for example, temperatures well above the seasonal average from the beginning of May in the Mediterranean area and also in the first half of June which was characterized by meteorological situations typical of more advanced phases of the summer season.

“The CAREheat results put just some of the signs of climate change before our eyes but we must be aware that we are only at the beginning of a broader process and we are faced with increasingly frequent signs of what is to come– comments Gianmaria Sannino, head of the Enea Division of Models and technologies for the reduction of anthropogenic impacts and natural risks – In this context, research is and will be a key element to inform and guide future environmental policies, as indeed it has finally established COP28:in fact, the results of the latest Conference of the Parties in Dubai will guide the update of the national climate action plans for 2025, for a more ambitious intervention and targeted financing.Among the salient points of COP28, the need to triple renewable energy capacity and double improvements in energy efficiency was also established for the first time;we reached a historic milestone with a fund of over $700 million to support the most vulnerable countries; We have committed to reducing greenhouse gas emissions by 43% by 2030 and have finally adopted a framework for climate adaptation and to protect our natural ecosystems by stopping deforestation by 2030. Studies like CareHeat will represent an invaluable resource to guide the planning of adaptation strategies,” concludes Sannino.

“In light of the conclusions reached in the recent COP28, the results of the CAREHeat project become even more relevant, becoming key elements to inform and guide future environmental policies, with a strong global commitment against the effects of climate change", underlines Ernesto Napolitano of the Enea Laboratory of Climate Modeling and Impacts.

The CAREHeat project aims to develop new methodologies for predicting and identifying heat waves, understand its propagation and impacts on the environment, biodiversity and economic activities, such as fishing and aquaculture.In addition to Enea and Cnr, they participate in the project financed by Esa as part of the "flagship actions" of the European Commission, the French research institutes Cls (Collect Locatisation Satellites) and Ifremer (Institut Français de Recherche pour l'Exploitation de la Mer), the non-profit Mercator Ocean International (France) and +ATLANTIC CoLAB (Portugal).