Cape Times: Millions of Nigerians may have to flee rising sea levels in the next half century, as ocean surges swamp some of Africa’s most expensive real estate and its poorest slums, scientists say. Nigeria, stretching from the Sahara to the Gulf of Guinea, could come under triple attack from climate change as the desert encroaches on its northern pastures, rainfall erodes farmland in its eastern Niger Delta, and the Atlantic Ocean floods its southern coast. But the greatest concern is …