A look at man's potential effect on the world's areas of wilderness. As the human population has grown, only a quarter of Earth's land now remains uninhabited (aside from Antarctica). Although around 12% is protected, this may not be enough — providing such places are not just 'enclosures' and bordering territories are also managed. Ethiopia's Semien Mountains are increasingly encroached upon for farming land, and this example leads to the question of overpopulation. Some interviewees argue that it is not just about numbers: how humans consume their natural resources is also important. However, others believe that the world would be greatly more sustainable if the population level was reduced to about half its current level. Jonathon Porritt believes that this could be achieved simply: by good education on family planning. Consumption of fresh water is highlighted: there are now 40,000 more dams in existence than in 1950. The controversy over drilling for oil in the Arctic National Wildlife Refuge is discussed by both its advocates and opponents. E. O. Wilson's concept of biophilia is discussed, and David Attenborough believes that a child's innate love of wildlife, for whatever reason, is being lost in adulthood. An answer to deforestation is found in Costa Rica, where farmers are paid to allow their pasture to revert to forest for its water ecosystem services. The also deals with climate change and related global warming, which is now happening at a faster rate than ever before. (thetvdb.com)