Lagos, on Nigeria's Atlantic coast, is home to an estimated 20 million people or more. It keeps growing: one local demographer estimated that 5,000 people were moving to Lagos every day, mostly from the Nigerian countryside. Babies are born and people die in the city every day, and some residents move away again.

Almost everything the city uses comes from outside it. Lorries bring food from farms across Nigeria, imported food arrives through the port, and it is sold in the city's markets and kept in people's homes. Petrol and diesel are delivered to fuel stations. Piped water from the state water corporation reaches only part of the city, so many households pump their own water from boreholes. Electricity comes from the national grid, but the grid delivers far less power than Nigeria needs, so homes and businesses run diesel generators, and vehicles burn petrol on the city's crowded roads.

Almost everything the city throws away has to go somewhere. Collection trucks take household rubbish to landfills such as Olusosun, where in March 2026 they were queuing for five to fourteen days to unload, and rotting waste releases methane. Sewage drains from homes into the lagoon, and when it rains, stormwater runs off roofs and roads into the lagoon and the Atlantic Ocean. Exhaust and generator fumes rise into the air above the city, and at night buildings and roads give off the heat they absorbed during the day.

Source: ESS lesson population.2.1, citing This Day, 3 March 2026 (Olusosun and the truck queues) and The Guardian, 27 October 2022 (5,000 people a day); Reuters, via CNBC Africa, 28 April 2026 (grid supply and generators); British Geological Survey, Africa Groundwater Atlas, Lagos case study, 2019 (piped water and boreholes)