Definition: A squatter settlement is a self-built, temporary settlement, often constructed illegally with poor quality materials.

Highlight: Only 10% of residents have access to proper septic tanks, while 33% rely on pail latrines that discharge directly into drains or rivers.

Example: Water access is severely limited, with only 16% having access to water vendors and 55% relying on wells or boreholes.

Vocabulary: Borehole - A deep, narrow hole made in the ground to locate water supplies.

Highlight: Lagos faces a daily water deficit of 407 million gallons.

Example: Open drains and pit latrines contaminate boreholes with sewage, leading to cholera and dysentery.

Highlight: Lagos residents spend $12.5 billion annually on energy production, primarily through generators.

Example: Power only works for an average of 4 hours daily, meeting less than one-third of the city's needs.

Quote: "Nigeria has signed provisional agreements worth $80bn with Chinese companies to upgrade its oil and gas infrastructure."

Highlight: Sea levels are projected to rise by about 1m in the 21st century, threatening this low-lying coastal city.

Example: New urban developments like Eko Atlantic aim to benefit the poorest through the 'trickle down effect'.

Definition: Trickle down effect - The theory that benefits for the wealthy will eventually flow to all members of society.