ecopolis
a hundre years ago, the largest city in the world was london with a population of 6.5 million. today it is dwarfed by tokyo. with barely a quarter the population of london a century ago the tokyo metropolitan area has since musroomed to 35 million propelling it to first place in the growth is largely due to a single factor migration from the countryside to the city it is just one of many to have overtaken london which with a population of 7.5 million today doesn't evn make the top 20
This rural-to-urban migration can now be seen in scores of cities around the globe and it has brought us to a pivatal moment in human history in 1900 most people lived in the countryside with a littel over 10 million the meteoric growth of megacities-there are now more than 25 in total-has brought with it huge environmental and social problems cities occupy just two percent of the land surface of the earth but consume three-quarters of the resources that are used up each year expelling the half digsted remains in clouds of greenhouse gases billions of tons of solid waste and rivers of toxic sewage their inhabitants are making ruinous demands on soils and water supplies for fook and on forests for timber and paper.Returning the world's population to the countryside isn't an option. diividing up the planet into plots of land on which we could all survive self-sufficiently would create its own natural disasters, not to mention being highly unlikely to ever happen. If we are to protecgt what is left of nature, and meet the demand to improve the quality of living for the world's developing nations a new form of city living is the only option. The size of a city creates economies of scale for things such as energy generation, recycling, and public transport. It should even be posible for cities to partly feed themselves. Far from being parasites on the world, cities could hold the key to sustainable liveing for the world's booming population-if they are built right.
fortunately, governments, planners, architects, and engineers are beginning to wake up to this idea, and are dreaming up new ways to green the megacities. Teir approaches rely on two main principles: recycle whatever possible and remove as many cars as possible. So as well as developin energy -efficient buildings, emphasis is being placed on increasing the use of public transport and redesigning how cities are organized to integrate work and living areas into a single neighborhood, rather than separating cities into residential, and industrial zones.
The big ideas are still being defined, but many cities already have showcase eco-projects. For example, at the new home of melbourne city council in australia, hanging gardens and water fountains cool the air, wind turbines and solar cells generate up to 85 percent of the electricity used in the building, and rooftop rainwater collectors supply 70 percent of its water needs. In Berlin, Germany's new Reichstag parliament building cut its carbon dioxide emissions by 94 percent by relying on carbon-neutral vegetable oil as its energy source. In San Diego, californian, garbage trucks run on methane extracted from the landfills they deliver to. In Aust