Middle East and Africa
Climate Change and the Nile: Flood and Famine
The country in the Nile basin will suffer if they do not learn to cooperate.
To the untrained eye, the satellite photos of north-west Ethiopia on July 10th may have seemed benign.
They showed a relatively small pool of water next to an enormous building site on the Blue Nile, the main tributary of the Nile river.
But the project under construction is the Grand Ethiopian Renaissance Dam, which is more than halfway complete.
And the water is why it is so controversial.
Since Ethiopia announced its plan to build the dam, it has inspired threats of sabotage from Egypt, which sits downstream and relies on the Nile for electricity, farming and drinking water.
Egypt claims that it is entitled to a certain proportion of the Nile's water based on colonial-era treaties.
Ethiopia dismisses those agreements.
The pool of water in the photos suggested that it was beginning to fill the reservoir behind the dam, reducing the river's flow.
That turns out not to have been the case.
The pool was deemed by Egypt to be a result of construction and seasonal Nile flooding.
But the alarms it raised are indicative of how sensitive negotiations between Egypt, Ethiopia and Sudan have become.
Talks over such things as how fast to fill the reservoir and how to operate the dam have stumbled.
And a potentially huge complication looms over any discussion of the Nile's future: climate change.
By 2050 around a billion people will live in the countries through which the Nile and its tributaries flow.
That alone will put enormous stress on the water supply.
But according to a study by Mohamed Siam and Elfatih Eltahir of MIT, potential changes to the river's flow, resulting from climate change, may add to the strain.
但是，根据麻省理工学院的Mohamed Siam和elfatih Eltahir对气候变化造成的河流的流量变化的研究，情况可能会更加严峻。
Messrs Siam and Eltahir conclude that on current trends the annual flow could increase, on average, by up to 15%.