XXII Giornata mondiale dell’acqua
THE MEDITERRANEAN SYSTEM
A hotspot for climate change and adaptation
Report presented to the Conference “XXII Giornata dell’Acqua”
(Rome, 21-22 March 2023)
The latest AR6 Climate Report, WG2, “Impacts, Adaptation and Vulnerability”, 2022, for the first time in the IPCC history devotes the Cross-Chapter Paper 4 to the Mediterraean region. This region is known for its exceptional environmental and socio-cultural richness which originates from three surrounding continents. Climate change, in its di#erent and diverse aspects, interacts very strongly with a variety of problems resulting from urbanization, water and air pollution, biodiversity loss and degradation of land and marine ecosystems. "e Mediterranean is moreover expected “to be one of the most prominent and vulnerable climate change hotspots” (AR6, WG1, 2021, Chapter 10).
Adaptation options impact all the above environmental and social aspects, especially considering that a very probable scenario for the near future will simply obey the principle of “business as usual”, through simple inertia of the economic system."is conference hence focuses on the Mediterranean Sea as a climate hotspot both scienti!cally and regarding adaptation measures.
The conference is composed of two parts.
The first part focuses on the physical sciences of the Earth (geodesy, physical oceanography, atmospheric dynamics) with the goal of providing a scienti!c background aimed at establishing what is known with certainty, what is debatable, what is simply still unknown and what are the projections of future climate scenarios. Hence each scienti!c presentation poses one overarching question, the answer to which can be important for the global climate, the Mediterranean one and their mutual interactions.
The second part focuses on adaptation measures, which obviously depend, !rst and foremost, on the scienti!c knowledge and second on the practical possibilities.
The most obvious, and well-known example of adaptation is the network of barriers against sea level rise and extreme sea level events constructed in the Netherlands since last century, and the 21st century example of the Venice barriers (the MOSE), recently completed, for the protection of the city and its lagoon.
Further adaptation options for climate change impacts on marine ecosystems and !sheries include improving and enlarging the regional network of marine protected areas, sustainable fishery practices, developing collaborative monitoring and sustainable aquaculture.
Adaptation options to sea level rise in the Mediterranean include also more modest nature- based solutions, such as beach and shore nourishment, dune restoration, with engineering playing a major role through breakwaters, seawalls and dykes. Many engineering- based coastal adaptations, however, imply large impacts on the coastal ecosystems and the environment as well.
An extreme engineering solution is the envisioned control dam at the Gibraltar strait for mitigation of sea level rise in the entire sea.
The dam would most likely involve major impacts on the entire physical, chemical and biological properties of the basin. "ese, and many more options, will be discussed in the Round Table scheduled for the second day of the conference. "is report summarizes the issues debated at the conference.
The short summaries provided by the speakers re$ect their scienti!c insights as well as their preferences for possible adaptation measures. "e organizers hope that this report will be of stimulus to the Mediterranean community at large for the preservation of this uniquely rich basin and of its heritage to the future generations.
Responsibility for the information and views expressed in this document lies solely with the "Commissione Ambiente".