Source: http://www.hrama.com/skycity/
How will we deal with urban populations that could see some cities topping 50 million or so people by the mid Century? The above project may be one way. Here is where city populations are as of 2010ish.
| 1 | Tokyo | Japan | 34,600,000 |
| 2 | Canton | China | 26,300,000 |
| 3 | Jakarta | Indonesia | 25,800,000 |
| 3 | Shanghai | China | 25,800,000 |
| 5 | Seoul | Korea (South) | 25,600,000 |
| 6 | Mexico City | Mexico | 23,500,000 |
| 6 | Delhi | India | 23,500,000 |
| 8 | Karachi | Pakistan | 22,100,000 |
| 9 | Manila | Philippines | 21,800,000 |
| 10 | New York | United States of America | 21,500,000 |
| 11 | São Paulo | Brazil | 21,300,000 |
| 12 | Bombay | India | 21,100,000 |
| 13 | Los Angeles | United States of America | 17,100,000 |
| 14 | Osaka | Japan | 16,800,000 |
| 15 | Beijing | China | 16,700,000 |
| 16 | Moscow | Russia | 16,200,000 |
| 17 | Cairo | Egypt | 15,900,000 |
| 17 | Dacca | Bangladesh | 15,900,000 |
| 19 | Calcutta | India | 15,800,000 |
| 20 | Buenos Aires | Argentina | 14,400,000 |
| 21 | Bangkok | Thailand | 14,200,000 |
| 22 | Istanbul | Turkey | 13,700,000 |
| 22 | Tehran | Iran | 13,700,000 |
| 24 | London | Great Britain | 13,200,000 |
| 25 | Lagos | Nigeria | 13,000,000 |
| 26 | Rio de Janeiro | Brazil | 12,800,000 |
| 27 | Paris | France | 10,600,000 |
| 28 | Shenzhen | China | 10,000,000 |
| 28 | Tientsin | China | 10,000,000 |
| 30 | Chicago | United States of America | 9,750,000 |
| 30 | Kinshasa | Congo (Dem. Rep.) | 9,750,000 |
| 32 | Lima | Peru | 9,550,000 |
| 33 | Madras | India | 9,450,000 |
| 34 | Bangalore | India | 9,400,000 |
| 35 | Lahore | Pakistan | 9,300,000 |
| 36 | Wuhan | China | 9,250,000 |
| 37 | Bogotá | Colombia | 9,150,000 |
| 38 | Taipei | Taiwan (Rep. of China) | 8,900,000 |
| 39 | Hyderabad | India | 8,450,000 |
| 39 | Nagoya | Japan | 8,450,000 |
| 41 | Johannesburg | South Africa | 8,400,000 |
| 42 | Washington | United States of America | 8,050,000 |
| 43 | Saigon | Vietnam | 8,000,000 |
| 44 | Philadelphia | United States of America | 7,250,000 |
| 45 | Boston | United States of America | 7,200,000 |
| 45 | San Francisco | United States of America | 7,200,000 |
| 45 | Shenyang | China | 7,200,000 |
| 48 | Hong Kong | China | 7,150,000 |
| 49 | Ahmedabad | India | 6,900,000 |
| 50 | Singapore | Singapore | 6,650,000 |
| 51 | Kuala Lumpur | Malaysia | 6,600,000 |
| 52 | Baghdad | Iraq | 6,400,000 |
| 53 | Chengtu | China | 6,350,000 |
| 53 | Chungking | China | 6,350,000 |
| 55 | Dallas | United States of America | 6,300,000 |
| 56 | Santiago | Chile | 6,250,000 |
| 57 | Sian | China | 6,100,000 |
| 58 | Riyadh | Saudi Arabia | 6,000,000 |
| 58 | Luanda | Angola | 6,000,000 |
| 60 | Belo Horizonte | Brazil | 5,900,000 |
| 60 | Toronto | Canada | 5,900,000 |
| 62 | Houston | United States of America | 5,850,000 |
| 63 | Miami | United States of America | 5,800,000 |
| 64 | Bandung | Indonesia | 5,650,000 |
| 65 | Detroit | United States of America | 5,600,000 |
| 66 | Nanking | China | 5,500,000 |
| 66 | Poona | India | 5,500,000 |
| 68 | Atlanta | United States of America | 5,400,000 |
| 68 | Madrid | Spain | 5,400,000 |
| 70 | Khartoum | Sudan | 5,200,000 |
| 71 | Saint Petersburg | Russia | 5,150,000 |
| 71 | Surat | India | 5,150,000 |
| 73 | Milan | Italy | 5,050,000 |
| 73 | Rangoon | Myanmar | 5,050,000 |
| 75 | Guadalajara | Mexico | 4,900,000 |
| 76 | Alexandria | Egypt | 4,825,000 |
| 77 | Abidjan | Côte d’Ivoire | 4,725,000 |
| 78 | Nairobi | Kenya | 4,700,000 |
| 78 | Shantou | China | 4,700,000 |
| 80 | Harbin | China | 4,650,000 |
| 80 | Sydney | Australia | 4,650,000 |
| 82 | The Ruhr | Germany | 4,600,000 |
| 83 | Colombo | Sri Lanka | 4,550,000 |
| 83 | Monterrey | Mexico | 4,550,000 |
| 85 | Surabaya | Indonesia | 4,500,000 |
| 86 | Ankara | Turkey | 4,475,000 |
| 87 | Hangchou | China | 4,425,000 |
| 88 | Berlin | Germany | 4,375,000 |
| 89 | Chittagong | Bangladesh | 4,275,000 |
| 90 | Phoenix | United States of America | 4,225,000 |
| 91 | Accra | Ghana | 4,200,000 |
| 91 | Barcelona | Spain | 4,200,000 |
| 91 | Porto Alegre | Brazil | 4,200,000 |
| 94 | Brasília | Brazil | 4,125,000 |
| 94 | Casablanca | Morocco | 4,125,000 |
| 94 | Melbourne | Australia | 4,125,000 |
| 94 | Naples | Italy | 4,125,000 |
| 98 | Tsingtao | China | 4,050,000 |
| 99 | Montreal | Canada | 4,000,000 |
| 99 | Recife | Brazil | 4,000,000 |
