Mediterranean Winter Weather: Dry Climate Change
As the East Coast of the U.S. suffers a blast of winter weather, a dry Mediterranean looks on jealously, wishing it had some of that wetness.
The East Coast storm is a major one-time weather event, but the winter droughts that have plagued the Mediterranean from Spain to Israel have been a trend in the climate for decades.
The lands around the Mediterranean Sea have been parched during winter for the past few decades, and recent research points to human-caused climate change as one of the culprits.
“The magnitude and frequency of the drying that has occurred is too great to be explained by natural variability alone,” said Martin Hoerling, a research meteorologist with the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory and lead author of a paper published in the Journal of Climate this month, in a press release.
The region depends on winter rainfall for much of its water, so the dry winters, which started in the 1970s, could have serious consequences for agriculture and drinking water.
“This is not encouraging news for a region that already experiences water stress, because it implies natural variability alone is unlikely to return the region’s climate to normal,” said Hoerling.
Ten of the 12 driest winters on record have occurred during the last two decades, noted the report by NOAA and the Cooperative Institute for Research in Environmental Sciences.
The researchers found that greenhouse gas increases explained approximately half the increasing dryness from 1902 to 2010. Other factors affecting the Mediterranean's climate are the cyclical climate pattern called the North Atlantic Oscillation and natural variability.
The dry winters also correlate with climate change models that have predicted drought for the Mediterranean.
“The question has been whether this projected drying has already begun to occur in winter, the most important season for water resources,” Hoerling said. “The answer is yes.”
Reds and oranges highlight lands around the Mediterranean that experienced significantly drier winters during 1971-2010 than the comparison period of 1902-2010. (Wikimedia Commons).
Winter precipitation trends in the Mediterranean region for the period 1902-2010. (Courtesy: NOAA).