Almeria in southern Spain -- with its 20,000 hectares of greenhouses -- is one perhaps and the Qattara Depression, which covers around 7,000 square miles (18,100 square km) of land below sea level in northeast Egypt, is another.

"By bringing these technologies together (we can) address some major problems -- create zero-carbon food in some of the most water-stressed parts of the planet, produce abundant renewable energy, revegetage deserts ... as well as providing food and livelihoods for large numbers of people in parts of the world that are really going to be suffering from climate change over the course of the next few decades."