Atlantropa, also referred to as Panropa, was a gigantic engineering and colonisation idea devised by the German architect Herman Sörgel in the 1920s and promoted by him until his death in 1952. Its central feature was a hydroelectric dam to be built across the Strait of Gibraltar, which would have provided enormous amounts of hydroelectricity and would have led to the lowering of the surface of the Mediterranean Sea by up to 200 metres (660 ft), opening up large new lands for settlement, for example in the Adriatic Sea. The project proposed four additional major dams as well:Across the Dardanelles to hold back the Black Sea
Between Sicily and Tunisia to provide a roadway and further lower the inner Mediterranean
On the Congo River below its Kwa River tributary to refill the Mega-Chad basin around Lake Chad providing fresh water to irrigate the Sahara and creating a shipping lane to the interior of Africa
Suez Canal extension and locks to maintain Red Sea connection
Sörgel saw his scheme, projected to take over a century, as a peaceful European-wide alternative to the Lebensraum concepts that later became one of the stated reasons for Nazi conquest of new territories. Atlantropa would provide land and food, employment, electric power, and most of all, a new vision for Europe and neighbouring Africa.
The Atlantropa movement, through its several decades, was characterised by four constants:Pacifism, in its promises of using technology in a peaceful way;
Pan-European sentiment, seeing the project as a way to unite a war-torn Europe;
Eurocentric attitudes to Africa (which was to become united with Europe into "Atlantropa" or Eurafrika), and
Neo-colonial geopolitics, which saw the world divided into three blocs—America, Asia and Atlantropa.
Active support was limited to architects and planners from Germany and a number of other primarily northern European countries. Critics derided it for various faults, ranging from lack of any actual cooperation of Mediterranean countries in the planning to the impacts it would have had on the historic coastal communities left stranded inland when the sea receded. The project reached great popularity in the late 1920s/early 1930s, and for a short period again, in the late 1940s/early 1950s, but soon disappeared from general discourse again after Sörgel's death.
The plan was inspired by the then-new understanding of the Messinian salinity crisis, a pan-Mediterranean geological event that took place 5 to 6 million years ago. The contemporary geologists proposed that the large salt deposits surrounding the Mediterranean coast were the result of its partial isolation by a shrinking of the seaways connecting to the Atlantic. Today it is a majority opinion among geoscientists that the Mediterranean underwent a significant drawdown during that period.
The Utopian goal was to solve all the major problems of European civilisation by the creation of a new continent, "Atlantropa", consisting of Europe and Africa and to be inhabited by Europeans. Sörgel was convinced that to remain competitive with the Americas and an emerging Oriental "Pan-Asia", Europe must become self-sufficient, and this meant possessing territories in all climate zones. Asia would forever remain a mystery to Europeans, and the British would not be able to maintain their global empire in the long run – hence a common European effort to colonise Africa was necessary. The lowering of the Mediterranean would enable the production of immense amounts of electric power, guaranteeing the growth of industry. Unlike fossil fuels, this power source would not be subject to depletion. Vast tracts of land would be freed for agriculture – including the Sahara desert, which was to be irrigated with the help of three sea-sized man-made lakes throughout Africa. The massive public works, envisioned to go on for more than a century, would relieve unemployment and the acquisition of new land would ease the pressure of overpopulation, which Sörgel thought were the fundamental causes of political unrest in Europe. Sörgel also believed the project's effect on the climate could only be beneficial. Sörgel believed that the climate could be changed for the better as far away as the British isles due to a more effective Gulf Stream creating warmer winters. The Middle East under the control of a consolidated Atlantropa would be an additional energy source and a bulwark against the Yellow Peril.
The publicity material produced for Atlantropa by Sörgel and his supporters contain plans, maps, and scale models of several dams and new ports on the Mediterranean, views of the Gibraltar dam crowned by a 400-metre tower designed by Peter Behrens, projections of the growth of agricultural production, sketches for a pan-Atlantropan power grid, and even provision for the protection of Venice as a cultural landmark. Concerns about climate change, earthquakes, when mentioned, were framed as positives rather than negatives. Sörgel's 1938 book Die Drei Grossen A has a quote from Hitler on the flyleaf, demonstrating that the concept was not inconsistent with Nazi ideology.
After the Second World War, interest was piqued again as the Western Allies sought to create closer bonds with Africa and combat communism, but the invention of nuclear power, the cost of rebuilding, and the end of colonialism left Atlantropa technologically unnecessary and politically unfeasible, although the Atlantropa Institute remained in existence until 1960.
Most proposals to dam the Strait of Gibraltar since that time have focused on the hydroelectric potential of such a project, and do not envisage any substantial lowering of the Mediterranean sea level. A new idea involving a tensioned fabric dam stretched between Europe and North Africa in the Gibraltar Strait could cope with any future global sea-level rise outside of the Mediterranean Sea Basin.
In Gene Roddenberry's novelisation of Star Trek: The Motion Picture, the Strait of Gibraltar has been dammed. Roddenberry may have borrowed the idea from Sörgel via the popular works of Willy Ley, whose book Engineers' Dreams describes both Atlantropa and Sörgel's other grand design, the forming of an inland sea in central Africa.
In Philip K. Dick's 1962 prize-winning alternate history novel The Man in the High Castle, the Nazis, after winning World War II, embarked on "Project Farmland", wherein the Mediterranean Sea was dammed and drained. The project was completed under the direction of Baldur von Schirach, and was said to have reclaimed huge areas of farmland. Atlantropa was also mentioned in the second season of Amazon's original series based on the novel.
In Arthur C. Clarke's novel Rendezvous with Rama, the Mediterranean is referenced to have been drained, providing a vast trove of archaeological finds, as well as land for new settlements.
The video game Railroad Tycoon II: The Second Century features a series of futuristic scenarios set in the (at the time of the game's release) near future. Some of which centre on the construction of such a drainage project, the development of the new lands created by this, and later the management of a crisis that results in the basin becoming flooded again.
In Tim Parise's science fiction novel Ships of the Desert, the portion of the Atlantropa project that dealt with the refilling of the Mega-Chad Basin has been carried out by redirecting the Ubangi River north through a canal 550 kilometres (340 mi) long.