African cities face two key transitions: urbanisation and climate change. How can African cities urbanise resiliently and sustainably, and ultimately – be liveable? Green spaces are one lever action at the disposal of cities, which are often overlooked and underappreciated in the competition for land when urbanising. What are the dynamics between green spaces and urbanisation in African cities? What is the potential for green spaces to boost resilience to extreme weather, like heat waves, and cities’ sustainability, such as pollution regulation? On 5 July 2022, experts, discussed these trends, the potential role that green spaces can play in the future of African cities, and what lessons can be learned from other parts of the globe. The presentation was be based on the forthcoming OECD study on green spaces: Boosting resilience in African cities: Role of green spaces.

1. Marie Trémolières, CSAO/OCDE
Brilé Anderson, CSAO/OCDE
Jorge E. Patiño, RiSE Group, EAFIT University
Rafael Prieto-Curiel, Complexity Science Hub Vienna
Join the conversation on Twitter:
#GreenTalks @OECD_ENV

2. Table of contents
Context
Two phenomenon:
Rapid urbanisation and
climate change
Green spaces
Data gaps
01 Urbanisation
dynamics
What happens to
green spaces?
02 Air Pollution
Do green spaces decrease
pollution?
03 04
Heat waves
What is the potential to use
green spaces as a nature-
based solution to extreme
heat?

3. By the end of this century, cities in West Africa are likely
to experience dangerous heat almost half of the year,
even under scenarios of 1.5 to 2C warming.
Image by Rogerio Rogeriomda from Pixabay
Rohat, G. et al. (2019), “Projections of Human Exposure to Dangerous Heat in African Cities
Under Multiple Socioeconomic and Climate Scenarios”, Earth’s Future, Vol. 7/5, pp. 528-546,
https://doi.org/10.1029/2018EF001020.

4. By the end of this century, cities in West Africa are likely
to experience dangerous heat almost half of the year,
even under scenarios of 1.5 to 2C warming.
1950
1980
1990
2000
2015
+ 950
million
people
by 2050
https://africapolis.org/en

5. Green spaces emerging priority on political agendas
Urbanisation, territoires et environnement

6. What is the availability of green spaces? Example of Abuja (Nigeria)
Urbanisation, territoires et environnement
20.4% of the urban footprint of Abuja
is covered in green space
https://esa-worldcover.org/en https://africapolis.org/en

7. © 2022 Secretariat of the Sahel and West Africa Club.
% green space in 5625
urban agglomerations
Publicly available on OECD/SWAC

8. The availability of green space in cities is
impacted by urban form.

9. More compact cities, less
green spaces
Loss of ecosystem services
Sprawl vs. Green space

10. City configuration vs. Green space
© 2022 Secretariat of the Sahel and West Africa Club.
Higher density in the city
centre, more green space

11. Does urban green space help reduce outdoor
air pollution?

12. Source: https://sites.wustl.edu/acag/datasets/surface-pm2-5/
© 2022 Secretariat of the Sahel and West Africa Club.
More green space,
less outdoor pollution
micrograms
(ug)/m
3
i
2019

13. But it is not only the absolute amount of urban
green space matters for some ecosystem services!

14. © 2022 Secretariat of the Sahel and West Africa Club.
Proximity to green space matters for some ecosystem
services
Green space needs to be available, BUT …
People need to live nearby to benefit from its
cooling effects.

15. Availability not always translates to proximity.

16. What % of the population live within 300m of trees (at least 1ha) ?
Approx. 20 % of the urban footprint of Abuja
and Accra is covered in green space
Availability is not proximity!!
Green spaces show limited potential as a
nature-based solution to heat
© 2022 Secretariat of the Sahel and West Africa Club.

17. Policy implications

18. Preserve greenspace in city planning by
embracing vertical growth –building higher
buildings with greater density– in the
already built-up areas.
© 2022 Secretariat of the Sahel and West Africa Club.

19. Image by Portraitor from Pixabay

20. Plan for having patches of urban green
spaces of different sizes, located scattered
throughout the city and connected by green
corridors to maximize the delivery of
ecosystem services and the cooling effect.
© 2022 Secretariat of the Sahel and West Africa Club.

21. Image by Albretch Fietz from Pixabay

22. Support/Coordination with National
governments:
- Planning documents / Decentralisation.
- Enforcement responsibilities.
- Funding / Climate Finance.
- Capacity building.
- Monitoring and evaluation.
© 2022 Secretariat of the Sahel and West Africa Club.

23. Image by StockSnap from Pixabay

24. Image from African DRONE - https://africandrone.org

25. Urban green spaces can help to boost
resilience, sustainability, and public health.
© 2022 Secretariat of the Sahel and West Africa Club.
© United Nations, https://sdgs.un.org/goals

26. How urban areas are built and configured in the
coming decades will have long-term implications
on the environment and the lives of billions of
people.
* Seto, K. C., & Pandey, B. (2019). Urban Land Use: Central to Building a Sustainable Future. One Earth, 1(2), 168–170.

28. Thank you!
Contact brile.anderson@oecd.org for questions
and comments
Marie Trémolières, CSAO/OCDE
Brilé Anderson, CSAO/OCDE
Jorge E. Patiño, RiSE Group, EAFIT University
Rafael Prieto-Curiel, Complexity Science Hub Vienna
Green Talks Live
5 July 2022
Publication: Week of 18th July