The next few decades will bring an era of rapid urbanisation and unprecedented climate stress in African cities. Green spaces can boost the resilience of cities to heat waves, floods, landslides, and even coastal erosion, in addition, to enhancing sustainability by improving air quality, protecting biodiversity, and absorbing carbon. All of which can enhance well-being. Yet, data on the availability of green spaces in African urban agglomerations is scarce. This analysis fills the gap by combining new and novel data sources to estimate the availability of green spaces in 5 625 urban agglomerations with 10 000 inhabitants and above. The rest of the report then uses this novel dataset to first evaluate the dynamics between urbanisation and green spaces, and second, explore the potential of green spaces to boost the resilience and sustainability of cities in the future. The results show that as urban agglomerations become larger and more compact, green spaces disappear, exacerbating their vulnerability to climate change and deteriorating liveability. However, building taller buildings (i.e., growing vertically), offers a way for cities to grow whilst minimising loss of green space. Results show that more green space can boost sustainability by significantly lowering air pollution in African cities, which could be vital for public health in the future since outdoor air pollution is rising. The potential for green spaces to enhance resilience to climate events, like heat waves, depends on the location of green spaces throughout the city and the percentage of the population that lives close to a green space (i.e., within 300 metres). Green spaces may play a limited role in coping with heat waves in a city like Khartoum where only 3% of the population lives close to a green space, but could be a nature-based solution to heat waves in a city like Abuja, where 55% of the population can benefit from its cooling effects. Moving forward, local actors have clear evidence of the power of green spaces to build a sustainable and resilient future. Still, the report reveals that local actors need support from regional and national actors to realise the potential of green spaces.