The Rationale Behind the NBI Global Resource Centre

What is nature-based infrastructure? 

The term nature-based infrastructure (NBI) is used to describe areas or systems that harness nature to provide infrastructure services for people, the economy, and the environment. This includes: 

  • Naturally occurring ecosystems, such as forests, mangroves, wetlands, and grasslands. 
  • Hybrid infrastructure combining engineered or “grey” structures with nature-based solutions, such as rain gardens, green roofs, sustainable urban drainage systems, and porous pavements. 

Why should we invest in NBI? 

Building with nature offers us a more sustainable alternative to engineered (grey) infrastructure. Its regenerative characteristics make it more efficient, less carbon-intensive, and less expensive to manage and maintain. It offers long-term value for money. 

What is more, NBI provides a wide range of additional social and environmental benefits—from preserving biodiversity and sequestering carbon to creating jobs and improving citizens’ well-being. It can also play a key role in helping communities adapt to climate change by alleviating the effects of extreme weather events such as floods, droughts, and storms.  

How can NBI contribute to sustainable development? 

Infrastructure provides public assets and services that are essential for human and economic well-being, such as roads, schools, hospitals, and sanitation facilities. As such, expanding and upgrading these assets will play an important part in fulfilling the UN’s sustainable development goals. Ensuring that new infrastructure is cost-effective, environmentally friendly, and resilient to changing climates is key to addressing future challenges as well as today’s demands. 

Who is behind the NBI Global Resource Centre? 

The MAVA Foundation, a philanthropic organization working to conserve biodiversity for the benefit of people and nature, has partnered with the Global Environment Facility (GEF), the largest multilateral trust fund aimed at tackling our planet’s most pressing environmental problems, to fund the NBI Global Resource Centre. GEF support comes from its Special Climate Change Fund. 

The project is implemented by the United Nations Industrial Development Organization (UNIDO) and executed by the International Institute for Sustainable Development (IISD). 

Who can benefit from the NBI Global Resource Centre? 

The NBI Global Resource Centre helps investors, governments, and infrastructure project developers to understand the full scope of costs and benefits associated with NBI projects. This approach is based on the premise that investing in nature will lead to better climate adaptation, healthier ecosystems, and more cost-effective infrastructure solutions for all. We seek to improve the track record of NBI to deliver infrastructure services. 

The Methodology Used by the NBI Global Resource Centre

What is a Sustainable Asset Valuation (SAVi)? 

The NBI Global Resource Centre draws on a methodology called the Sustainable Asset Valuation (SAVi) tool. SAVi is a simulation methodology used to calculate the financial value of NBI projects. It uses three core methods—systems thinking, system dynamics simulation, and project finance modelling—to determine the long-term costs of a given project. 

SAVi assigns a dollar value to: 

  • The ecosystem services delivered by a project, as well as their direct and indirect co-benefits. 
  • The financial performance of the ecosystem services under different climate change scenarios, with climate data derived from the Copernicus Climate Data Store. 
  • The capital and operating costs of grey infrastructure required to provide the same level of services.    

We work directly with clients to provide customized valuations to inform infrastructure decision-making. 

What is systems thinking? 

Systems thinking is about understanding how the different parts of a system are interconnected. It is a qualitative approach that forms the basis for the other methodologies used by the NBI Global Resource Centre. Systems thinking helps us to predict the outcome of decisions across sectors and actors, in different places, and over time.   

We can use systems thinking to understand the impacts of NBI projects. Restoring a forest, for example, would influence the global climate (by storing carbon), support local livelihoods (by providing wood), and foster climate adaptation (by reducing flood risks), among other things. 


What is system dynamics? 

System dynamics is a quantitative methodology. It uses numbers and equations to model the links between the parts of a system. With system dynamics, we can integrate social, economic, and environmental indicators in a single analysis. This helps us to calculate the impacts of infrastructure projects on different economic sectors, people, and the environment. System dynamics allows us to look at both short- and long-term developments.  

For example, system dynamics allows us to calculate the dollar value of avoided flood damages after reforestation, or we can model how many tonnes of carbon a reforestation project would store.   

The central tool for system dynamics modelling is the causal loop diagram (CLD). 



What is project finance modelling? 

Project finance modelling helps us to assess the economic feasibility of an infrastructure project over time. This methodology is used to calculate the long-term, projected cash flows of a project to help investors better understand the potential financial risks and rewards associated with the project. 


What is spatial modelling, and how do you use it? 

We use spatial data and models to quantify, map, and value the benefits provided by ecosystems, such as carbon storage, water filtration, food provision, and timber production.  

For the spatial analysis, we use an open-source suite of software models developed by Stanford University—the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST). The maps produced by InVEST show us where ecosystem services are provided and how they would change under different scenarios, for instance, when land uses change. We can analyze different spatial scales, such as entire landscapes or a single town. 


How do we consider climate change in the assessments? 

Our assessments of NBI projects consider different climate scenarios using information about weather and climate trends from the EU Copernicus Climate Data Store. This allows us to understand how climate risks affect the financial performance of infrastructure projects. It also helps us understand how infrastructure projects affect climate resilience.  

For example, reforestation can help people adapt to climate change by protecting them from increasing floods and droughts. By using climate scenarios, we can show that these benefits can be even more pronounced under more extreme climate change predictions. 


What are the credentials of this simulation methodology?  

Our methodology has been validated and tested on over 15 projects. For example, we assessed stormwater infrastructure in South Africa, mangrove preservation in Senegal, and agroforestry in Belgium. 

The simulations use best-in-class climate data from the EU Copernicus Climate Data Store. IISD has tested the integration of this data into SAVi models, including on two projects funded by the GEF. 

In 2020, the UN System of Environmental-Economic Accounting, Experimental Ecosystem Accounting (SEEA EEA) included the SAVi methodology in their Guidelines on the Use of Ecosystem Accounts in Policy Scenarios. 

Your NBI valuation 


How are NBI projects identified and selected for valuations?  


The NBI Global Resource Centre invites public, private, and civil society entities to submit NBI projects for valuation. We will also solicit NBI projects from strategic partners and encourage stakeholders to submit projects for valuation. Interested parties can submit their request for valuation on our website. 

We will review fully completed project questionnaires against a list of selection criteria. The Project Steering Committee will validate the selection of projects twice per year.   


Who conducts the valuations? 

The NBI Global Resource Centre was established by IISD and draws on their previous experience valuing infrastructure projects. IISD’s experts conduct the valuations in close collaboration with project stakeholders. The Technical Steering Committee will provide regular feedback and guidance to the NBI Global Resource Centre on the NBI valuations. 


What are the outputs of the valuations?  

For each NBI project, we calculate the dollar value of the ecosystem services it provides. This includes climate-related services such as carbon storage and adaptation benefits. In addition, we evaluate the biophysical, social, and economic co-benefits of NBI—from job creation to increased industrial or agricultural outputs.  

We also compare the capital and operating costs of the NBI project to the equivalent grey infrastructure that would be needed to provide the same services. For example, how much would it cost to have a water treatment plant instead of a wetland that cleans water? 

Finally, we analyze how ecosystem services and other benefits can be affected by climate change, population growth, land cover change, and other pressures over time. 


What types of ecosystems and ecosystems services can be included in the valuations?  

NBI includes many ecosystems, such as lakes, mangroves, forests, dunes, rivers, and grasslands. These ecosystems provide different services that we can value in economic terms. We focus on: 

  • Ecosystem services that complement or replace grey infrastructure or that provide general infrastructure benefits such as flood protection or water filtration. 
  • Ecosystem services that reduce costs for adaptation and support economic activities. For example, an existing wetland can provide water for agriculture and avoid extra investments in water storage and irrigation. 
  • Cultural services related to activities like recreation, tourism, agriculture, and fisheries. 

For each valuation, we choose which services to focus on with our clients.  

How do you record and present the results of the NBI valuations?  

We create a technical report with the full suite of simulation results, including the value of the ecosystem services and the financial performance of the project. It will also explain how we co-designed the simulation with the project stakeholders. 

An annex will contain the data we used for the NBI valuation, the references, the data input sheets, and the simulations models.