An Interactive Map on Urban Growth

The BBC has provided a great interactive map detaing urban growth in cities from 1955 to 2015. It's pretty amamzing to see the phenomenal growth of cities in Asia, especially compared to the slow growth of cities in the west.

From BBC's website:

The World's urban population is expected to hit 4 Billion between 2015 and 2020, about the as same China becomes more than 50% urbanized. Most of the growth will happen in Africa and Asia, with Africa's Urban population growing fastest in percentage terms and Asia seeing the biggest volume of growth.

To view the map, click here.

So what is your opinion of the map and it's projections?