By the end of the 21st century 85% of our global population will be living in cities.By then cities as we know it today have ceased to exist.The majority of humans would have organized themselves into Megacities and Super Urban Conglomerates of 40 million people or more and Megacities would have replaced nations and became self supportive as economic drivers and engines for growth and compete at a global level for resources, top talents and businesses.This urbanization trend would be exclusively for the new and upcoming global economy.However we are under threat of over stressing our global environment put in place by the general ignorance that resulted into over-consumption, environmental degradation and destruction, pollution and resource depletion.The 21st century now gives us the opportunity to use the urbanization trend and address the human inflicted calamities and stress put on to our global environment during the 20th century and reverse and reset the global environmental imbalances.Megacities and Super Urban Corridors clearly behold the opportunity and in their drive to attract top talents and businesses and operating in a stressed and scarce natural resources environment.Megacities and urban areas in general will demand new performance specifications, design parameters and conventions to create highly efficient community support structures and address all pertinent environmental issues and embed long terms solutions.My presentation will be outlined the thoughts, principles and ideas that have formed the baseline of our current thinking and summarizes the key trends and a kaleidoscope of opportunities, ideas plus potential solutions.We recognize that there will be no single answer or a single solution other than we have to Rethink! Our cities now.