Almost imperceptibly, we are stepping off the consumption treadmill

Twenty years ago, Beijing was a city of bicycles. They queued by the thousands at traffic lights on roads where cars were rare, next to grocer stalls piled high with winter cabbages.

Today, it is the bicycles that are rare in Beijing. Five million cars swirl around eight ring roads that encircle the metropolis, which chokes in smog for much of the year. Quaint old “hutong” pedestrian neighborhoods have been replaced in the city’s suburbs by high-rise apartments and shopping malls. With money building in their bank accounts, residents now can afford meat instead of cabbages.

And so goes the rest of this Asian giant. The industrialization of China has driven a quarter-billion people from dirt-poor rural villages into modern megacities, whose breakneck construction and galloping consumption by a burgeoning middle class are transforming the planet as a whole.