Actually, shockingly, we were learning about Africa (yes I will get to your questions) and anyway: The percentage of Africa that is wilderness: 28% The percentage of North America that is wilderness: 38% That's the whole of North America, sorry, but it's all I have and you asked that question Aug 19 so you must be dying for an answer!

I have been researching this question for 30 years The answer depends on how the word developed is defined For Alaska, the 600,000 persons are mostly located in urban areas, and consume only a few hundred square miles of land. Most of the 591,000 square miles of Alaska are wilderness area, owned by the federal and state governments and native tribes. For the other 49 states which have about 300 million persons on about 3 million square miles of land, I offer two sets of statistics: developed 7% cropland 18% pasture and range 36% managed forest 12% natural forest, desert, wetlands, etc. 27% so we can say that about 27 percent of the 49 states are wildlands, with about a quarter of this protected as official designated wilderness areas pasture and range can have wildland attributes depending on the intensity of domesticated animal grazing relative to wild animal use we can say that 93 percent of the 49 states are open space developed area of 7 percent or 210,000 square miles (the world's highest amount, or about 21 percent of the world's developed area of about 1 million square miles) urbanized and urban, 100,000 square miles exurban and rural settlement, 60,000 square miles transportation, utility corridors, waste disposal and mining sites, 50,000 square miles 80 percent of Americans are urban, or 240 million on 100,000 square miles, at a relatively low average urban density of 2,400 per square mile 20 percent of Americans are rural, either in scattered exurban patches, or more remote rural settlement, and this 60 million people on 60,000 square miles have a settlement pattern of 1,000 per square mile; lower due to the larger residential lot sizes another measure is pavement, about 50,000 square miles of the USA are paved over, with 40,000 in roads and parking, and 10,000 in houses and buildings, or about 75 percent of the developed area of 210,000 square miles is vegetation, largely lawns but also wooded streams and scattered patches of open space within urban areas

28% of Africa being wilderness doesn't sound plausable. Africa is about 11.7 million square miles; the Sahara Desert is about 3.5 million square miles. I'm guessing the Sahara is pretty much all wilderness, and just by itself is 30% of Africa...if only 10% of the remaining 7.2 million square miles is wilderness, then that comes to 4.2 million square miles, or 36%. It's probably more, though...40% or more seems like a safe bet.