FeliX (Functional Enviro-economic Linkages Integrated neXus), a project of the International Institute for Applied Systems Analysis, is a system dynamics model of global social, economic, and environmental Earth systems. Critical interdependencies among these systems are incorporated to recreate the complex dynamic behavior which characterizes the Anthropocene .
Implemented in Vensim, the model consists of stocks and flows, the interactions among which are defined by coupled differential equations. Flows define feedback loops which propagate impacts and integrate outcomes across the eight model sectors: Economy, Energy, Carbon Cycle, Climate, Biodiversity, Water, Population and Land Use. Elements of the model are calibrated to historical data [1900-2010] (as available) from the FAO, IEA, CDIAC, IPCC, World Bank, and UNIHP.
After calibration, Felix scenario outcomes project on a global scale major stock changes (e.g., depletion of natural resources, accrual of carbon dioxide in the atmosphere) as well as the aggregate consequences of policies and technologies (e.g., afforestation, emissions reduction) over time. Independent historical data and future pathways are used to validate these projections.
The baseline--or Business as Usual (BAU)--scenario was constructed as a reference for GEOSS for the purposes of global impact assessment. The definition, calibration, performance and outcomes of the BAU scenario are documented in detail in the DISCUSSION section of this website.
Though a carefully simplified ‘mock-up’ of complex Earth systems, the Felix model achieves a comprehensive scope, capturing vital mechanisms and facilitating insights into nine societal benefits areas (SBAs): disasters, health, energy, climate, water, weather, ecosystems, agriculture, and biodiversity. The main dynamic problems addressed by the model include (links to specific entries in discussion section):
- Population Dynamics and Aging
- Development jeopardized by ecosystem changes
- Alternative measures of development
- Increasing energy demand
- Investments in energy technology and production capacity
- Fossil fuels securing most of the needs for energy
- Alternative sources of energy competing for market share
- Food security
- Anthropogenic CO2 emissions (energy generation and land use & land use change)
- Impact of rising carbon concentrations (atmospheric and oceanic)
- Water scarcity
- Biodiversity loss
FeliX is a model that has been developed and applied in a team effort at IIASA over the course of several years and projects, led by IIASA/ESM research scholars Dr. Felicjan Rydzak and, subsequently, Dr. Brian Walsh, with significant foundational contributions from IIASA/ESM staff members Dr. Michael Obersteiner, Florian Kraxner, Dr. Steffen Fritz, and Dr. Ian McCallum.
 Steffen, Will et al. “The Anthropocene: From Global Change to Planetary Stewardship.” Ambio 40.7 (2011): 739–761. PMC. Web. 18 Feb. 2015.