​Urban Green Economy Model (Urban GEM)
A systems-based decision-support tool for sustainable and resilient cities.
Why Urban GEM?
Cities are at the forefront of climate action, economic transformation, and social inclusion.
Yet urban decision-making often remains fragmented across sectors and time horizons.
Urban GEM enables cities to:
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Assess integrated impacts of urban policies across economic, social, and environmental dimensions
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Design and compare decarbonization pathways aligned with net-zero and climate resilience goals
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Test investment strategies under different assumptions on technology, behavior, and governance
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Reveal feedback dynamics, the emergence of synergies and unintended consequences across urban systems
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Support evidence-based dialogue among planners, utilities, housing agencies, and policymakers
The Urban Green Economy Model (Urban GEM) is a downscaled, city-level adaptation of the Green Economy Model (GEM), designed to support urban decarbonization, climate resilience, and inclusive development.
It provides cities with an integrated, quantitative framework to analyze policies and investments across key urban systems, assess trade-offs and co-benefits, and explore long-term transition pathways at the citywide scale.
Urban GEM builds on the proven system dynamics, stock–flow architecture of the GEM, while explicitly capturing the unique dynamics of urban environments, where buildings and land use, transport and energy infrastructure, air and water pollution, and social outcomes interact in complex ways.
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Built in collaboration with the Global Green Growth Institute (GGGI), in the context of the UP 2030 project.
Urban GEM retains the modular structure of the national-level GEM, while adapting its causal structure to urban realities.
Key features include:
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System dynamics modeling with explicit stocks, flows, and feedback loops
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Use of spatial data and maps, for the estimation of localized impacts, for instance in relation to ecosystem service provisioning.
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Modular architecture, allowing sectors to be activated or simplified depending on relevance and data availability
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Scenario-based analysis, enabling comparison of policy packages and investment pathways
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Quantitative outputs aligned with policy-relevant indicators (emissions, energy use, costs, social outcomes).
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Built using Vensim, allowing for a dynamic interaction with the model.
