Estimating Economic Resilience to Climate Impacts: The Gross Resilience Product (GRP) 

C limate impacts are reshaping economic realities across Africa. To understand what this means for future growth, the GCA Resilient Economies Index introduces an important new measure: the Gross Resilience Product (GRP). GRP identifies the share of a country’s GDP that remains resilient under projected climate impacts—offering a clearer picture of how climate hazards influence long-term development trajectories. Built using the Green Economy Model (GEM), it provides a quantitative, comparable estimate of climate-related risks to national economies.

1. The Analytical Framework
The Green Economy Model (GEM) is a systems-based, macroeconomic model designed to capture interactions among economic, social, and environmental indicators. It is built using System Dynamics to represent feedback loops across sectors and indicators reflecting different dimensions of development, allowing analysts to see how climate hazards affect core components of economic activity.

The model links climate impacts on infrastructure, land, and population to economic performance through three main channels:

• Capital accumulation (e.g. damage to buildings and equipment); 
• Labor productivity (e.g. reductions due to heat stress or health impacts); and 
• Total factor productivity (e.g. reflecting efficiency losses associated with climate-related disruptions to infrastructure). 

This structure enables the simulation of GDP trajectories under two scenarios: (i) without climate impacts (counterfactual baseline) and (ii) with climate impacts. The difference between these two trajectories defines the GRP, i.e., the proportion of GDP not affected by climate-related damage. 

2. Integration of Climate and Geospatial Data 
A distinctive key strength of this approach is the integration of geospatial exposure  using a multi-hazard, multi-asset method. Hazard maps—covering floods, droughts, storms, landslides and sea-level rise—are layered over assets such asbuildings, roads, energy infrastructure, as well as cropland, livestock and population. These allow to generate hazard maps for different climate scenario and return periods.  

The geospatial overlays identify the quantity (e.g. km of roads) and percentage of assets located in hazard-prone areas for each country. These exposure indicators are then aggregated and incorporated into GEM to estimate the economic implications of asset damage and reduced functionality. 

3. Estimating the Gross Resilience Product (GRP) 
Within GEM, climate impacts reduce capital stock, productivity, and output across agriculture, industry, and services. The model uses monthly temperature, precipitation, wind speed and data on wet-bulb globe temperature (WBGT) from the Copernicus Climate Data Store, across various climate models and climate scenarios, to estimate the probability of extreme events, and hence quantify the impacts on infrastructure and production.  

The GRP is then estimated as the percentage of GDP that remains unaffected by these modeled impacts over the period 2025–2050. GRP can be estimated on an annual basis, as an average over time, and can be accumulated over time. Countries with a GRP score below 90% have more than 10% of their economic output exposed to climate impacts. This indicator provides a standardized measure of economic resilience, comparable across countries and income groups. 

4. Key Findings 
Results from the Index show that 31 African countries have  more than 10% of GDP exposed to climate impacts. This indicates significant medium- and long-term risks to economic performance, employment and productivity. 

Higher-income countries—including South Africa, Namibia, and Botswana—tend to exhibit higher GRP scores, reflecting more diversified economies and greater adaptive capacity. On the other hand, these countries have a comparatively larger amount of infrastructure at risk of climate impacts.  

Lower-income, agriculture-dependent economies, such as Niger, show greater vulnerability due to high reliance on climate-sensitive sectors, and are also characterized by lower infrastructure availability and density. 

Some outliers, such as the Central African Republic, perform relatively well despite low income, reflecting specific economic structures (e.g., external support and peacekeeping-related income), as well as less extreme projected changes in climate trends. Specifically, projections for Central Africa show more stable trends in the medium and longer term for precipitation and temperature.  

 Overall, the findings highlight the importance of economic diversification and adaptive capacity. When combined with the Index’s policy and finance results, GRP helps illustrate where economic risk, policy ambition and financial readiness must be brought into closer alignment. 

5. Implications for Policy and Investment 
The GRP offers a robust, data-driven measure of the economic consequences of climate impacts, merging a macroeconomic (top down) and an asset-oriented (bottom up) approach, with clear implications for policy design and investment prioritization. It allows analysts and decision-makers to: 

• Quantify potential GDP losses under climate scenarios; 
• Identify sectors and assets where adaptation interventions is required, and where it yields the highest economic return; 
• Integrate resilience metrics into economic planning, infrastructure investment, and development finance. 

6. Advancing the Measurement of Economic Resilience 
The introduction of GRP represents a methodological step forward in resilience measurement. Its innovation lies in combining macroeconomic modeling, climate hazard analysis, and geospatial exposure assessment into a single, replicable framework that offers time-based outputs.  

Unlike traditional GDP-based assessments, GRP captures not just growth potential but also its vulnerability to climate shocks. It bridges the gap between physical risk data and macroeconomic outcomes, supporting a more comprehensive understanding of climate-resilient development. 

The ideas presented in this article aim to inspire adaptation action – they are the views of the author and do not necessarily reflect those of the Global Center on Adaptation.

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