The way in which megacities grow – often without an overarching controlling vision – only adds to the issues that they bring with them. This is largely due, says DESA, ‘to the challenges of providing urban jobs, housing, energy and infrastructure to mitigate urban poverty, expansion of slums and a deterioration of the urban environment’.

Infrastructure supply lags behind demand, basic public services – such as water connections and solid waste disposal – don’t reach the majority, and many residents live on marginal land where, says the ADB’s Wan, ‘they face risks from flooding, disease, and other shocks’. https://geographical.co.uk/culture/rapid-population-growth