Toti Scialoja wrote that “there is a branch that protrudes on the lake / of Como, suspended from that branch / a spider is reflected in the lake / but the dying wave of an oar / ripples, with the spider, in the lake / that branch of the Lake Como”.
In Italy there are one thousand and five hundred lakes, in the world there are more than one hundred million. Lakes are important for many reasons, the first of which is that they contain 87 percent of the planet’s fresh, liquid water. Lakes are essential resources for water supply and food security (particularly for irrigation and fishing), as well as tourist destinations, and a source of inspiration for poets and writers.
Lakes are also a valid warning system of climate change, through a series of physical, chemical and biological indicators. The conditions of the lakes “are essential climatic variables, because they contribute significantly to the characterization of the earth’s climate”, wrote three researchers in a study just published in the journal BioScience and entitled “Hot situation for lakes: the impact of climate change on aquatic ecosystems “.
Lakes are changing rapidly due to climate and anthropization, the combined effects of which are poorly understood and rarely evaluated globally. Those at high altitudes have less and less ice to feed them and the summers become longer and earlier.
The researchers speak of a “cascade of ecological and environmental consequences, such as higher summer water temperatures, alterations in water stratification and levels, decreased dissolved oxygen, increased likelihood of algae blooms and loss of habitat for the fish that live in cold waters ”. The repercussions affect everyone, because they involve fresh water supplies, water quality, biodiversity and, more generally, the benefits that ecosystems offer to society. ◆