Greenhouse gases affect the Mediterranean climate to the point of reducing rainfall. This is what emerges from the research published in the journal of the American Academy of Sciences (Pnas) coordinated by Giuseppe Zappa, of the National Research Council (Cnr), and carried out in collaboration with the British University of Reading and Imperial College London.
"We have analyzed the climate models and the simulations developed by the main research carried out in this area and we have seen that the increase in greenhouse gases leads to the variation of atmospheric circulation and a reduction in the amount of rain in the Mediterranean" he told ANSA Zappa, who He began his research at the University of Reading and who now works in the Cnr Institute of Atmospheric and Climate Sciences (ISAC).
The models "tell us that changes in rainfall are already underway - he continues - and have already been observed in North Africa and the Eastern Mediterranean; if CO2 emissions continue with current rates we expect them to become extended to more areas, such as Southern Italy ".
The Mediterranean is characterized by hot and dry summers, receives a large part of the rains during the cold season and these precipitations are brought about by low pressure phenomena. "We expect - Zappa notes - that greenhouse gases can change the Mediterranean atmospheric circulation in such a way that low pressure phenomena will become less frequent".
This is because atmospheric circulation depends on how heat is distributed on the surface, for example on the temperature of the seas: "greenhouse gases cause the oceans to heat up and this phenomenon changes the atmospheric circulation".
The warming of the ocean surface is not uniform, explains Paulo Ceppi, of Imperial College London, "there are some regions that heat up faster than others", causing "changes in the winds that make the Mediterranean regions drier".
However, the same research shows that the effect on rains could be quickly stopped by reducing emissions: "it does not mean
that we will recover the lost rain, but - note - that the situation will not continue to worsen ".
