Over the next 25 years, the worlds population will grow from 7 billion to 9 billion.By 2035 sixty to seventy percent of the worlds population will live in cites which means that new cities will emerge, existing cities will be transformed, and most all of our key economic, social and cultural activities will be urban.At the same time, cities will continue to experience an increased frequency and severity of environmental, social and economic shocks and stresses precipitated by climate change in combination with population growth and migrations.Planners, architects, engineers and city leaders are currently engaged in discussions centered on the following three important challenges: 1.Sustainability: How to plan for the growth of cities while at the same time reducing the citys negative impact on the ecosystems they are part of;2.Regeneration: How to plan and design cities that regenerate and repair the damage that has already been done to existing ecosystems.3.Resilience: How to develop and implement strategies that increase the resilience capacity of cities in the face of future environmental and economic shocks and stresses.Whats missing from the current discourse frame? Recognizing that simply reducing harm through sustainability and resilience are not adequate end goals, Ive expanded the current sustainable planning and design discourse frame, to include developing "the symbiotic city".This is a term and approach Ive developed to describe a vision of cities not simply surviving or doing less harm, but actually functioning in harmony with its inhabitants and natural environment.