Population - IMAGE
|Model Documentation - IMAGE|
|Institution||PBL Netherlands Environmental Assessment Agency (PBL), Utrecht University (UU)|
|Concept||The IMAGE framework can best be described as a geographically explicit assessment, integrated assessment simulation model, focusing a detailed representation of relevant processes with respect to human use of energy, land and water in relation to relevant environmental processes.|
|Solution method||Recursive dynamic solution method|
|Anticipation||Simulation modelling framework, without foresight. However, a simplified version of the energy/climate part of the model (called FAIR) can be run prior to running the framework to obtain data for climate policy simulations.|
The future state of the world depends on the population because total demand for goods and services equals the number of people times demand per capita.
Most population projections used as input to the IMAGE model have been adopted from published sources, such as data from the United Nations 1 and projections by the International Institute for Applied Systems Analysis (IIASA) 2. Behind these numerical projections are economic, technical, educational and policy assumptions that determine the estimated future population as the net outcome of fertility and mortality, adjusted for migration flows. This has provided internally consistent, overall population scenarios on the basis of underlying demographic trends.
In addition to total number of people, the population is broken down into gender, income classes, urban and rural, and educational level. These attributes are relevant for issues such as consumption preferences and patterns, and access to goods and services. Using a downscaling procedure 3, national and regional population can be projected at grid level to account for trends in urbanisation and migration within countries and regions.
Population data are used in energy and agricultural economics modelling, and in other IMAGE components, such as water stress, nutrients, flood risks and human health.
- UN (2013). World Population Prospects, The 2012 Revision, Volume I: Comprehensive Tables.Department of Economic and Social Affairs, Population Division,United Nations.
- W. Lutz, S. KC (2010). Dimensions of global population projections: what do we know about future population trends and structures?. Philosophical Transactions of the Royal Society B: Biological Sciences, 365 (), 2779-2791. http://dx.doi.org/10.1098/rstb.2010.0133
- Detlef P van Vuuren, Paul L Lucas, Henk Hilderink (2007). Downscaling drivers of global environmental change: Enabling use of global SRES scenarios at the national and grid levels. Global Environmental Change, 17 (1), 114-130.