Lake Garda getting warmer, two experts compare

31 July 2024

Both the Arena di Verona and Trentino Today following a NASA study in which researchers from the Edmund Mach Foundation collaborated. 235 lakes analysed in six continents. The presence of life on the sea bed is at risk, it emerges that Lake Garda is getting warmer and warmer. In the last ten years, the increase in summer surface water temperatures has been 0.2 °C.

According to Nico Salmaso, a researcher at the Mach Foundation, 'this temperature increase, which seems rather limited, has instead important effects, determining consequences both on the mixing dynamics of the deep waters and on aquatic communities. The effects of warming can be very important, particularly favouring the development of new algal species'. At the same time, the researchers also found that 'over the past 10 years, there has been a significant downward trend in algal nutrients in the water column. This decrease is a very positive sign for the health of Lake Garda and is necessary to counterbalance the undesirable effects on algal development caused by increasing lake temperatures'.

Roberto Battiston, professor of experimental physics at the University of Trento, in front of the temperature data of Lake Garda. He calls it 'an urgency to be solved for the lake, but above all for the planet and for the new generations. "There are eight billion of us on earth, we have created the problem and it is up to us to solve it," argues the former president of the Italian Space Agency and author of 'L'alfabeto della natura' (The alphabet of nature), a volume in which, as a populariser and essayist, he emphasises the need to reason in scientific terms about the complex phenomena - from the pandemic to the climate emergency - that society faces. A way of interpreting reality that we can all practise.

Returning to the effects of the lake's warming, over the last few years Lake Garda has shown an important trend towards a decrease in the events of complete mixing and reoxygenation, so that, compared to surface waters, the warming of the bottom waters appears even more evident. "The last complete circulation of waters was documented in 2006," Salmaso explains. On that occasion, temperatures of around 7.6 °C were measured in the bottom waters (below 200 m). At the end of 2015, as the state of incomplete mixing continued, deep water temperatures reached 8.6 °C. The trend of rising temperatures in the deep waters will come to a halt with the arrival of a colder winter, but what is certain, however, is that we are facing temperature levels never previously measured'.

There is therefore no longer any denying climate change...

Now anyone can see it because the effects are macroscopic. The climate has always changed, even more, with higher or lower temperatures. But never so rapidly. It is the speed of change that counts. Every passing day is the hottest ever (as shown by paleoclimatic analyses, ed).