Increasing ocean desertification due to climate change
2' min read
2' min read
These are the findings of an international study carried out by ENEA, in collaboration with the Ismar-Cnr Institute of Marine Sciences and the Chinese State Key Laboratory of Satellite Ocean Environment Dynamic.
The effects of climate are also being felt in the oceans. In little more than 20 years, the size of nutrient-poor ocean areas with low biodiversity has almost doubled, from 2.4 to 4.5% of the global ocean. These are the findings of an international study conducted by ENEA's Climate Models and Services Laboratory, in collaboration with the Ismar-Cnr Institute of Marine Sciences and the Chinese State Key Laboratory of Satellite Ocean Environment Dynamic, published in the scientific journal 'Geophysical Research Letters'. The phenomenon studied 'results in a severe nutrient deficiency and could have significant consequences on ocean health and global climate'.
Study and desertification risk
The study focuses on analysing changes in phytoplankton, i.e., the set of microorganisms that form the basis of the marine food chain and help mitigate climate change by removing atmospheric CO2 through their photosynthetic activity. "This phenomenon is very evident in the North Pacific Ocean, where the surface area involved is growing at a rate of 70,000 square kilometres per year," explains Chiara Volta, researcher at ENEA's Climate Models and Services Laboratory. "But desertification is increasingly affecting several oceanic regions, with a particular vulnerability in tropical and subtropical areas, where the decrease in available nutrients can have major impacts on productivity and biological diversity.
The explanation
The expert also offers an explanation: "This happens because of global warming, which causes the warmer, lighter water to remain at the surface, preventing mixing with the cooler, nutrient-rich water at depth," she argues. "Less mixing therefore means less 'food' reaching the surface to support the growth of phytoplankton and, consequently, the entire food chain.
Studied data between 1998 and 2022
.In their work, researchers examined time series of chlorophyll and phytoplankton satellite data between 1998 and 2022 in Earth's five major oceanic vortices (subtropical gyres) located in the North and South Atlantic, North and South Pacific and Indian Ocean.
