As I have written about both Abu Dhabi's green roofs, and Los Angeles's edible green roof, Dubai has outdone both.
Inhabitat.com reports that Dubai, in coordination with green landscaping firm, GCLA, are going to build a "Food City," complete "...off-the-grid, self-sufficient metropolis." Taste the Purest Tea on the Planet – Organic and Fair Trade Certified Shop Numi Organic Tea
How does one do that in Dubai, one of driest climates on earth? The answer (starting with green roofs!):
"...atmospheric water harvesting, solar desalination through concentrated solar collectors, grey water recycling, and application of hydroponic sand to minimize water loss."
All of this requires significant electricity, which will done via solar collectors focused on towers. Water Barrels and Storage
I wish Dubai luck, though I feel the project may be a bit ambitious.