Nature-based solutions are actions that use nature to solve environmental problems. Examples in cities would be setting up a wetland near a group of buildings to absorb floodwater, or building permeable pavements.
The world's developed countries have been implementing nature-based solutions since 2015 but Africa has fallen behind. We are part of a group of environmental scientists who analysed the plans of African countries to adapt to climate change. We found that only 15 African countries (27.7%) have implemented nature-based solutions. Just 119 projects have been set up in Africa to adapt to climate change in water, agriculture, forests and woodlands, coastal and marine areas, grasslands, and mountain habitats - and these are mainly in rural areas.
This is a problem because by 2050, African cities will house an additional 950 million people. Rapid urbanisation has been shown to be one of the major environmental threats that leads to deforestation and land degradation. City buildings develop an ecological footprint which encroaches on natural resources and affects surrounding ecosystem services.
African cities are also exposed to climate change effects. About 70% are at risk of flooding, urban heat waves, drought and storms.
Under the Paris Agreement, all countries have Nationally Determined Contributions. These are climate action plans which set out how the countries will reduce their greenhouse gas emissions and start adapting to climate change. Countries have to report on progress to the United Nations' Framework Convention on Climate Change.
We assessed the reports from all 54 African countries to identify evidence of and trends in nature-based solutions on the continent. We also examined publicly available Geographic Information Systems data on all African cities. This information shows the green spaces in cities.
We found that:
- urban planning still does not include nature-based solutions
- governments are not funding these projects or seeking enough funds from the private sector to set up nature-based solutions
- there is a lack of comprehensive evidence-based strategies and knowledge for successful implementation of nature-based solutions in African cities.
Nature-based solutions have been shown to work in developed countries and have helped many European cities to adapt to extreme climate events and reduce disaster risk. For instance, green roofs in Basel, Switzerland and Hamburg, Germany have resulted in connected green areas and increased these cities' resilience to climate heatwaves and floods by cooling the cities down and absorbing water.
Natural solutions in a changing climate
Nature-based solutions include green infrastructure (such as growing grasses and plants on roofs or down the sides of walls), urban agriculture, and planting small forests in cities. Sustainable guttering to improve urban drainage systems, and green roofs incorporating renewable energy are two more of these solutions.
In coastal cities, these solutions help protect coastal habitats and forests which provide flood defences and are useful in the management of sea levels. The same approach in landlocked countries can help urban reforestation, which cools cities and improves air quality.
Read more: How buildings in Johannesburg could benefit from green roofs
The International Union for Conservation of Nature has developed a global standard that countries can use to increase the scale and impact of their nature-based solutions projects. They emphasise that these projects must be cost effective and funded by public and private capital. The solutions should be able to be reproduced in other cities facing similar climate change problems.
Nature-based solutions acknowledge that cities will continue to grow. Urban expansion must be redesigned to accommodate growing populations while emphasising sustainable and city planning.
The solutions have also been punted globally as an approach to address extreme climate events, such as flooding, droughts, urban heat waves, and greenhouse gas emissions. Their effectiveness in urban areas depends on a city's scale, size, natural assets, and the way it is governed.
What's been done so far?
So far, only 15 African countries have put nature-based solutions projects in place, often neglecting urban areas. Those cities that have tried to green their urban areas are getting positive results: Lagos in Nigeria, Johannesburg in South Africa, Cairo in Egypt, Nairobi in Kenya, Accra in Ghana, and Addis Ababa in Ethiopia. The nature-based solutions in these cities include green road pavements and urban agriculture.
What's next?
Some of the sustainable development goals might not be achieved without adapting the master plans of cities and their urban development strategies. Introducing nature-based solutions to cities is vital if we want to protect the city environment from natural disasters and rising temperatures. This will also make urbanisation more sustainable.
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African countries must urgently integrate nature-based solutions in cities to make urban areas more resilient to climate change. African cities urgently need to:
- train city officials in how to set up nature-based solutions projects
- improve the way cities are governed so that urban planning always includes nature-based solutions
- collaborate with other African cities and promote what has worked elsewhere.
African governments must create national frameworks that foster urban climate resilience and monitor whether urban transformation is green and sustainable.
These are actions for municipality leaders, planners and development decision-makers. Only by greening our cities will we minimise the social and economic losses that are set to come with climate change.
(Razak Kiribou was the lead author of the research that this article is based on.)
Sintayehu W. Dejene, Research Project Manager at the Alliance Bioversity and International Center for Tropical Agriculture, CGIAR and Associate Professor of Production Ecology and Resource Conservation, CGIAR System Organization
Razak Kiribou, PhD Candidate, Africa Center of Excellence for Climate Smart Agriculture and Biodiversity Conservation, Haramaya University
