Report

Tree Planting for Climate Resilience in Freetown, Sierra Leone

An economic valuation of the "Freetown the Treetown" initiative

This assessment presents the economic valuation of the new phase of the successful "Freetown the Treetown" initiative that aims to plant, digitally track, and grow millions of trees to address challenges of deforestation and climate change. The climate adaptation efforts can lead to significant economic, social, and environmental benefits in Freetown, including reduction in infrastructure damages and loss of life from natural hazards such as flooding and landslides, as well as diminished carbon dioxide emissions and extreme heat. 

By Ronja Bechauf, Edoardo Carlucci, Marco Guzzetti, Michail Kapetanakis on January 9, 2025

Situated on a densely forested and mountainous peninsula in the Atlantic Ocean, Freetown, the dynamic capital of Sierra Leone, is home to approximately 1.5 million people. The city is experiencing rapid population growth and urbanization, 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 urban communities at increased risk from floods, landslides, coastal erosion, and extreme heat.

To reforest the city, the Freetown City Council, with the support of international partners including the World Bank, Bloomberg Philanthropies, and the Global Environmental Facility, has developed the successful "Freetown the Treetown" initiative, which focuses on planting, digitally tracking, and growing 1 million trees in the city. Looking to scale this initiative further to address the escalating challenges of deforestation and climate change, this Sustainable Asset Valuation (SAVi) assessment evaluates the new phase of the initiative. The new phase 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 extreme heat in Freetown.

Two scenarios will be assessed as part of this SAVi assessment:

  • NBI scenario 1, consisting of planting 3.7 million trees by 2050
  • NBI scenario 2, consisting of planting 5 million trees by 2050.

The assessment highlights the societal value of urban reforestation and land restoration, demonstrating that the project can play a critical role in supporting Freetown's climate adaptation strategies. These efforts will enhance water retention, mitigate infrastructure damage, reduce loss of life from natural hazards such as flooding and landslides, and decrease carbon dioxide emissions and extreme heat.

The implementation of the proposed nature-based infrastructure (NBI) project in Freetown is projected to deliver significant net benefits. By 2050, the total cumulative, net discounted benefit (at a 4% discount rate) of implementing NBI Scenario 1 is USD 21.68 million, while NBI Scenario 2 would generate USD 26.45 million. The greatest positive impacts of the project include the avoided damage to infrastructure from floods, landslides, coastal erosion, and sea level rise, followed by employment and income generation, as well as the prevention of loss of life from flooding and landslides. 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.

The assessment also includes a financial analysis that aims to ensure long-term financial sustainability of the project. The financial analysis identifies potential financing options that could support the Freetown the Treetown initiative to become financially viable, contributing to Freetown's climate resilience efforts.

Report details

Topic
Climate Change Adaptation
Project
The Nature-Based Infrastructure Global Resource Centre
Focus area
Climate
Economies
Publisher
IISD
Copyright
IISD, 2025