Tree planting for Climate Resilience in Freetown, Sierra Leone

Freetown is the bustling capital of Sierra Leone, situated on a densely forested and mountainous peninsula in the Atlantic Ocean. Rapid population growth and urban expansion is resulting in the loss of half a million trees each year. This urban deforestation, coupled with the impacts of climate change is placing Freetown’s 1.5 million residents at increased risk from floods, landslides, and extreme heat. Rising sea levels and erosion also threaten communities living along the coast.

This assessment aims to scale the successful #FreetownTheTreetown campaign, which was initially developed by the Freetown City Council, with the support of international partners including the World Bank, Bloomberg Philanthropies, and the Global Environmental Facility.

Encouraging tree planting by digitally tracking the growth of trees, the project is planning to plant millions of additional trees by 2050. This new phase of the project aims to restore mangrove forests, protect the city’s water supply, restore the Western Area Peninsula Forest, and continue to reduce damages from natural hazards and the urban heat island effect in Freetown.

We assessed two scenarios:

• Nature-Based Infrastructure scenario 1, consisting of planting 3.7 million trees by 2050.
• Nature-Based Infrastructure scenario 2, consisting of the more ambitious target of 5 million trees planted by 2050.

We found that for every USD 1 invested in this project, the societal return is USD 2.94 for NBI Scenario 1 and USD 2.79 for NBI Scenario 2. When accounting for discounted values, the returns are USD 2.14 and USD 2.04, respectively. These benefits are expected to grow as the frequency and intensity of extreme weather events increase, making tree planting an attractive climate adaptation strategy under future climate scenarios.