A majority of the world’s population lives in mega cities, of which there are 30, each of them home to between four and ten million people. By the year 2015 the number of mega cities is expected to rise to 60, with a combined population of 600 million. Currently cities account for around two-thirds of global energy consumption, 60% of water consumption and 70% of greenhouse gas emissions.
 
"Urban regions offer excellent opportunities for sustainable networking of supply and consumption as well as energy and mobility,“ says Professor Martin Faulstich, chairman of the advisory council on the environment of the German government, who will speak at the forum.

Exhibitors are also focusing on mega cities, with Siemens AG calculating that the urban market they can address is currently worth a total of around €300 billion per year. In the light of the importance of this segment, Siemens set up a new business sector at the company last year, under the name of Infrastructure & Cities. Dr. Willfried Wienholt, VP, urban development, Siemens, and also a speaker in the congress forum, sees cities as "facing the challenge of aligning growth and quality of life."
 
One particularly significant challenge for mega cities is sustainable management of water and waste water. Georg Huber, chairman of Huber SE of Berching, says that "in many cities supplies of water are insufficient. Processing waste water decentrally and turning it into high-quality water for industrial use can help alleviate the situation." Heiner Markhoff, president and CEO of GE Power & Water, says: "Membrane bioreactors are increasingly becoming the preferred technology for waste-water treatment in many areas of Europe and in densely populated areas around the world. The discharge from these reactors can be used for irrigation or as process water in industry."