He Atmospheric moisture transport, that is, the humidity that comes from the oceans and moves the atmospherewill have a greater influence on the appearance of droughts in the area of Mediterranean countries due to global warming, which will significantly increase the risk of desertification.
Specifically, It is estimated that at the end of the 21st century the chances of droughts They will increase between two and three times compared to current predictions, in a scenario in which the mass emission of greenhouse gases continues.
The humidity that transports and contains the atmosphere is essential for the occurrence of rainfallbut also of droughts In the Mediterranean basin area, this moisture comes mainly from the Atlantic Ocean and the Mediterranean Sea and although the rainfall of the last 150 years is the ones that could be foreseen, in the future we can only expect aridity and more droughts.
Drought is the future
Precipitation in the Mediterranean region has remained stable for the last 150 years and atmospheric dynamics, which mainly controls the rains, is not yet affected by heating, which does not imply that the area is not immersed in a global warming stage with multiple impacts.
Those are The conclusions of a study published by the magazine Nature, in which 52 scientific institutions collaborated by the Pyrenean Institute of Ecology (IPE) of the Higher Council for Scientific Research (CSIC).
Las rains in the Mediterranean do not present a significant long -term trendalthough a high variability in time and space controlled by the natural dynamics of the climate, which determines atmospheric circulation.
Although short periods of time and regions are recorded in which there are increases or descents of rainfall, These are framed in the characteristic variability of the climate in the regionindicates the CSIC.
However, Researchers warn that the region experiences a process of growing climatic aridity that will intensify by the increase in temperatures, according to projections, which will mean droughts more serious ecological and agricultural.
The study integrates data from more than 23,000 meteorological stations in 27 countries, including France, Italy, Morocco, Egypt and Greece, and more than 10 million Precipitation records, with an analysis of historical trends between 1871 and 2020.
The fact that rainfall has been stable, despite the variations between years and decades, could contradict previous investigations that They suggested a regional decrease in rainfall as a result of climate change.
Rain descents
“Although some previous investigations had suggested a tendency to decrease rainfall For a certain influence of global warming, the results of the broad set of data analyzed do not support this statement ”, in the words of Sergio Vicente, researcher at the IPE-CSIC and work leader.
However, warns that the region is immersed in a climate change scenario And “we must bear in mind that natural climatic variability processes overlap with the effects of greenhouse gases.” “In some cases, these effects are very evident, as in the increase in temperatures,” he adds.
In the case of lThe main mechanisms of atmospheric circulation, which are the most important condition From the dynamics of rainfall, the effect of warming is, according to the CSIC researcher, “more diffuse” and so far it could be said that “it cannot be clearly identified.”
Los Models indicate for the future a decrease in rainfall in the Mediterranean region as a consequence of alterations in atmospheric circulation associated with higher levels of heating.
Temperature increase
In addition, the region experience a process of growing climatic ariditywhich is, especially to the increase observed in temperatures, which lead to an increase in the demand for water by the atmosphere.
This increase affects water losses due to high evaporation, and amplifies the stress to which the areas of natural vegetation and crops are subjected. This influence is much more important in drought periods, in which the availability of water decreases and each drop counts.
More extensive droughts
Las future temperature projections foresee that these aridity conditions intensify in the future. As a consequence, the region would experience droughts more serious ecological and agricultural, the study points out.
It is Aridity increase process is independent of the dynamics of precipitation observed And scheduled for the future, “but it is obvious that this process would be accentuated by the rainfall descent indicated by the models,” Vicente points out.
This situation “underlines the pressing need to address the complex challenges posed by climate change on the availability of water resources in the Mediterranean region, ”he said.
The team concludes that this study will have important implications For the environmental, agricultural and water resources planning of the region.
LInvestigation also participated, among anotherS, the universities of Zaragoza, Barcelona, La Rioja, Vigo, Valencia, the Complutense of Madrid, the Geociencias Institute and the State Meteorology Agency (Aemet).