What will the Mediterranean look like by the end of the century? It all depends on carbon emissions, a new study finds.
Using pollen records from the last 10,000 years, the researchers were able to assess the impact that temperature changes have historically had on plant life in the region. They then projected the forecast temperature rises forward, producing computer models of four different emissions scenarios.
They found that, unless global warming is limited to 1.5 degrees Celsius above preindustrial levels, Mediterranean ecosystems will change more than they have any time during the past 10,000 years. Deserts will expand and deciduous trees will start to disappear, with implications for political stability, too. For the researchers, it’s a call to action.
“The main message is really to maintain at less than 1.5C,” Joel Guiot, a researcher at Aix-Marseille University in France, told the Guardian. “For that, we need to decrease the emissions of greenhouse gases very quickly, and start the decreasing now, and not by 2020, and to arrive at zero emissions by 2050 and not by the end of the century.”
Global temperatures have already risen by an average of 1 degree Celsius since the industrial era began. That goes up to 1.3 degrees for the Mediterranean basin. The Paris Agreement, which will go into force next week, calls for warming to be limited to 2 degrees Celsius, with a more challenging target of 1.5 degrees.
The researchers were intrigued by what the difference between the two scenarios outlined in Paris would mean in the Mediterranean, which they say is unusually sensitive to temperature changes. “It doesn’t seem like much to people,” Dr Guiot told the Associated Press, but the models found significant differences resulting from an extra 0.5 degrees C. of warming.
If warming were to reach 2 degrees, the study finds that deserts would expand substantially in Spain, North Africa and the Near East. Vegetation would also be affected, with deciduous trees beginning to disappear from the Mediterranean basin and be replaced with other vegetation.
And those impacts are intensified for the two other scenarios the scientists looked at, where temperature rises are as high as 5 degrees above preindustrial levels.
Although this study does not specifically look at the effect of climate change on food production, other research has found that the temperature rise would limit the productivity of olive trees and other staples of Mediterranean cuisine, Guiot told the Guardian.
Climate could also have important political consequences. While political and social changes probably caused the downfall of historic empires in the region — including the ancient Greeks, Romans, and Egyptians — “climate has always been important there,” Guiot explained to the Associated Press.
More recently, climate has been linked to political conflicts such as Darfur and Syria. Extended periods of drought in the region could see mass migrations as people compete over limited resources and move to areas with more water.
“The Med is very sensitive to climactic change, maybe more than any other region in the world,” Guiot said. “A lot of people are living at the level of the sea, it also has a lot of troubles coming from migration. If we add additional problems due to climate change, it will be worse in the future.”
Material from the Associated Press contributed to this report.