Many assumptions but overall ni kufyam as far as global clout is concerned. Per capita GDPs will increase but only Nigeria will be in the top 20 in total GDP. Africa's only hope of growing its global clout this century is increased integration (Some estimates place Africa's GDP at about $29 Trillion in 2050 probably the same as the EU then). China in 2050 will be a gigantic beast. India will almost definitely be part of the UN Security Council. As for Kenya, we need to find those massive oil reserves asap.

Top 20 World GDPs in 2050 in US$bn

1 China 53,856
2 US 37,998
3 India 34,704
4 Brazil 8,825
5 Japan 8,065
6 Russia 8,013
7 Mexico 7,409
8 Indonesia 6,346
9 Germany 5,822
10 France 5,714
11 UK 5,598
12 Turkey 5,032
13 Nigeria 3,964
14 Italy 3,867
15 Spain 3,612
16 Canada 3,549
17 South Korea 3,545
18 Saudi Arabia 3,090
19 Vietnam 2,715
20 Argentina 2,620

https://www.pwc.com/en_G...-report-january-2013.pdf