Table 2.

Number of people within each continent living in catchments predicted to have acceptable periphyton growth and N-limitation (catchment type 1), undesirable periphyton growth with N-limitation (catchment type 2), acceptable periphyton growth and P-limitation (catchment type 3) and undesirable periphyton growth with P-limitation (catchment type 4).

Continent	Type 1	Type 2	Type 3	Type 4
Africa	1,025,741,239	44,092,182	—	88,646,459
Asia	2,459,163,941	233,927,831	817,010,315	763,406,287
Europe	18,793,629	2,224,451	19,826,163	654,844,514
North America	252,507,691	—	123,627,603	188,139,679
Oceania	617,330	44,262	4,786,156	19,024,132
South America	3,747,21,630	—	4,761,001	39,165,729
World1	4,131,193,677	280,244,464	969,519,504	1,734,202,668

¹Excludes Antarctica and Greenland.