Until less than 200 years ago most cities were compact and very densely-populated, and usually de-lineated by natural boundaries like a hilltop or a peninsula or a bend in a river and/or surrounded by protective walls.  Such distinct boundaries, whether natural or man-made, acted like a corset that kept the city trim and efficient.  Being small in area, rarely exceeding a few sq. km, most cities could be easily crossed on foot, and everyone lived and worked within these narrow confines or just a short distance beyond in the surrounding fields.  

EVERYONE lived close to where they worked – how amazing is that..?  

NAARDEN, Netherlands

However, once the threat of armed brigands or invading armies sufficiently diminished, the walls came down and, fuelled by increased prosperity and the introduction of mechanised and motorised transport, cities spread out to the horizon and became bloated beyond recognition.  

Having discarded their walls (corsets), which kept them in shape, Cities became obese – thus they became OBeCITIES.  

Los Angeles – a waste of a beautiful name..!

Obese humans are unhealthy, un-attractive, and very INEFFICIENT and WASTEFUL for the amount of energy (food) consumed.

Obese cities are unhealthy, un-attractive, and very INEFFICIENT and WASTEFUL for the amount of energy consumed and land occupied  

By 2050 (if not earlier) many of our existing cities (ObeCities) will have become anarchic and dangerous places in which to live, rather as Detroit has become in the last 50 years.  As I write this many cities in America and some in Europe are rapidly going the same way.   By 2100 I expect at least 50% of people in advanced nations will have migrated to the safety of OA-Cities