Climate change not only causes decreased agricultural production due to droughts and desertification in Mediterranean North Africa and the ‘Fertile Crescent’ of the Middle East – it will also cost the region several thousands square kilometers of its most productive cropland as a direct result of sea level rise in the Nile Delta – and possibly a much larger area at risk of upstream storm surge floods.
From that same Nile Delta millions of people would have to be displaced, when the sea level rises by just 50* centimeter.
We say just 50 – because that’s not what the world’s political leaders are aiming for. The officially aim for 2 degrees warming – and the real sea level specialists, like James Hansen, draw powerful paleoclimatological analogues and model calculations to show that that will lead to large-scale melting of the Antarctic ice sheet and even complete melting of the Greenland ice sheet. Highest estimates indicate that a 2 degree warming could lead to 12 to 32 meters sea level rise. Well-established sea level rise studies that take into account ice-melting feedbacks (like this one, published in Science) state global average sea levels will likely be between 0.8-2.0 metres higher at the end of the century. New studies by Hansen’s research group, like this one in Atmospheric Chemistry & Physics from July 2015 state that could be an underestimation still.
The UNEP report that the Nile Delta sea level rise submergence map comes from dates from the nineties. That might also be an underestimation as newer studies show that decreasing sediment build-up from the now-contained Nile River over its flood plains leads to subsidence of the entire Nile Delta, including vulnerable cropland.
Every centimeter of subsidence of course adds to every centimeter of sea level rise – rapidly increasing the flood risk. Egyptian scientists go as far as to predict a third of the Nile Delta might be submerged by 2030. The demographic effects would then likely drastically exceed the projections for climate migrant flows from the area. About half of the Egyptian population lives in the Nile Delta, including major cities like Alexandria and Port Said. The Egyptian population has quadrupled between 1950 and 2010. By 2030 the UN estimates further Egyptian population growth to 117 million people.
© Rolf Schuttenhelm | www.bitsofscience.org