AGI – The Alpine environment and the Italian seas are the special observers in monitoring the possible effects of climate change in Italy. Our glaciers melt more each year, and the seas show evident temperature increases, with marked alterations in the Ligurian, Adriatic and Northern Ionian Seas; evidence of water stress for crops and plant species in some case studies analyzed by National system for environmental protection (Snpa).
These are just some of the 20 indicators chosen by the working group of 18 technicians, suitably assisted by dozens of other experts coming not only from the Environmental Protection Agencies or the Higher Institute for Environmental Protection and Research, but also from other research institutes and bodies, contained in the 248-page volume that represents the first study of this level on monitoring the impacts of climate change in Italy, presented today through the dedicated online event.
© Photo: Emanuele Perugini
Bracciano lake, drought
The Snpa report on climate change impact indicators provides a first insight into the phenomena potentially connected to climate change in Italy and represents a dynamic and updatable system, also according to any new scientific findings. To keep the phenomenon of climate change under observation and measure the effectiveness of the contrast and adaptation actions adopted, Snpa has identified a first set of 20 national indicators and 30 regional pilot cases relating to 13 vulnerable sectors already identified as part of the National Strategy adaptation to climate change and the subsequent draft of the National Plan.
They range from water resources to cultural heritage, passing through agriculture and food production, energy, fishing, health, forests, marine and terrestrial ecosystems, soil and territory, alpine / Apennine environment and coastal areas. The alpine environment shows evident tendencies towards deglaciation.
Due to the combined effect of high summer temperatures and the reduction in winter precipitation, there is a constant loss of mass (mass balance of glaciers, national indicator and pilot case on Valle d’Aosta and Lombardy), with an annual average equal to to over one meter of water equivalent (i.e. the thickness of the layer of water obtained from melting ice) from 1995 to 2019: ranging from a minimum of 19 meters of water equivalent for the Basodino glacier between Piedmont and Switzerland to a maximum of almost 41 meters for the Careser glacier, in Trentino Alto Adige. To these phenomena is added a clear tendency towards permafrost degradation.
The analysis of two regional pilot sites (Valle d’Aosta and Piedmont) shows an average warming of +0.15 C every 10 years with a high probability of “complete degradation” by 2040 in the Piedmontese site: in fact, permafrost occurs only in the presence of negative temperatures below the active layer of the soil for at least two consecutive years, a condition that risks disappearing by 2040.
Even when passing from the mountains to the sea, the situation shows unequivocal signs: the increase in sea temperature already corresponds to a significant variation in the distribution of species, with an increase in fishing in the Italian seas of those that prefer high temperatures (small species such as anchovy , sardinella, mullet, shrimp and pink shrimp), which are spreading further north in the Italian seas.
On the other hand, large species, sometimes of great commercial interest, such as cod, cantaro, sea bass, mackerel and bonito are penalized. This phenomenon is photographed by the “average temperature of the catch” indicator, calculated year by year on the basis of commercial catches, which has grown by more than one degree in the last 30 years (a phenomenon more marked in the southern seas, in the Tyrrhenian and Ligurian seas than in the ‘Adriatic). Changes in sea level are a source of concern for the consequences on the coasts: the increases, of the order of a few millimeters per year (average values of the trend equal to about 2.2 mm / year with peaks in the Adriatic Sea of about 3 mm / year), are continuous and appear irreversible to date.
The case of Venice deserves particular attention, where there is a combined phenomenon of eustatism (sea level rise) and subsidence (land level lowering): in the long term (1872-2019) the average sea level rise rate stands at 2.53 mm / year, value more than doubled to 5.34 mm / year considering only the last period (1993-2019).
Evidence of water stress for crops (maize, alfalfa and grapevine) and the plant species analyzed (natural environments typical of Friuli) are found in the pilot cases of Emilia-Romagna and Friuli Venezia Giulia, where the continuous shortage of water supply evaluated in several mm / decade can lead to possible long-term consequences on the growth and reproductive cycle, and a consistent loss of production with evident economic repercussions.
The signs that emerge seem to already outline critical factors for Italy both for natural resources and for the socio-economic sectors investigated: in most cases the trends detected already appear to be consistent with what is expected in a context of climate change, but it will be from the continuous observation of the phenomena over time, from the statistical analysis of the data and from the validation operations with data in the field, that the current evidence can be confirmed as well as purified from the effect of other factors and more clearly attributed to the changes in the climate in progress .
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