Half the world's population lives in cities. - According to the Global Risks report of the World Economic Forum, more than half of humanity currently lives in urban areas. The forecasts for 2050 predict 6.3 billion people living in cities by then, out of a total of more than 9 billion. This means that almost three quarters of the world's population will live in cities within 35 years, which will raise many problems, as this growth often happens without any planning and with inadequate...