Two hundred years ago, London was the only city with more than a million people. Today London does not even reach the top twenty of the world's largest cities. Within five years, more people will live in cities and towns than in the countryside for the first time in history.

for a quick quiz on today's cities

The World's Mega Cities

There are now 17 mega cities of over ten million people. By 2015 there will be 21.

Click on the cities to find out how their populations are expected to change.

The data on the map includes people that live beyond the city limits and commute to the centre. As more people arrive in cities every day, it is difficult to say how accurate these figures are.

Why are some of these cities predicted to grow faster than others?
Why do some parts of the world have no mega cities?

Size isn't everything. Some cities have a worldwide influence with less people.

Can you think of any cities that have a worldwide influence that are not one of the mega cities marked on the map?
In what ways do these 'global cities' have a worldwide influence?
Do these 'global cities' have anything in common?

Mega Cities: Good news or bad news?

Drag and drop the different statements into the table. On balance, do you think mega cities are good or bad news?

The world's nerve centres Mega cities have a different role from cities in the past. Better communications and speedy international transport brings people and goods closer together, and new ideas flow more easily from one mega city to another. In some ways, cities like Mumbai may now have more in common with Los Angeles than to other cities in India. But at the same time, others remain unplugged; 600,000 villages in India do not have a single phone.

Downtown Shanghai, China © Dermot Tatlow/Panos Pictures

The Quality of Life
In this globalised world, businesses have greater freedom to locate where they want to be rather than where they have to be. Cities compete for business, and the quality of life they can offer people from overseas is very important. The human resources company, William M. Mercer surveyed over 200 cities to find out which had the best ... and worst quality of life. The survey helps transnational companies compare the quality of life for their workforce living abroad.

Have a guess yourself before you look!

Rapidly growing cities cause huge headaches for planners - one is the quality of the air. Go to the next page to find out what it's like to live in nearly thirty different cities across the world.