Around 5000 years ago, the first cities emerged in Mesopotamia and the fertile valleys of the Tigris and Euphrates Rivers. Agricultural surpluses enabled a few people to start specializing in something other than agriculture. The farmer who now had extra grain could trade for a better spear or a winter fur coat. This specialization and the ability to trade goods and services is the basis of urbanization. And, there was enough food that the starving artist didn’t starve completely, so along with trade, culture emerged.
Cities grew at a modest pace until about 1800 when the Industrial Revolution took off in the UK and cities developed at staggering rates. Manchester, for example experienced a six-fold population increase from 1771 to 1831. London went from about one-fifth of Britain’s population at the start of the 19th Century to about half the country’s population in 1851. This rate of urbanization has not let up for the last two hundred years; in fact it is still accelerating. The growth of cities seen over the last two hundred years will now be repeated, but this time in just forty years.