摘要：We use CMIP3 multi-model simulations to show how individual hydroclimatic changes will
concur to determine even greater alterations of 21st century Mediterranean water cycle
characteristics, with contrasting behavior over land and sea. By 2070–2099, the average of
the models predicts a 20% decrease in land surface water availability and a 24% increase in
the loss of fresh water over the Mediterranean Sea due to precipitation reduction
and warming-enhanced evaporation, with a remarkably high consensus among
analyzed models. The projected decrease in river runoff from the surrounding land
will further exacerbate the increase in Mediterranean Sea fresh water deficit. 20th century simulations indicate that the 'transition' toward drier conditions has already
started to occur and has accelerated around the turn of the century towards the larger
rates projected for the 21st century. These tendencies are supported by observational
evidence of century-long negative trends in regionally averaged precipitation, PDSI and
discharge from numerous rivers; and are consistent with reported increases in
Mediterranean sea water salinity.
