Global Environment Outlook 3 (GEO 3)

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OUTLOOK 2002–32

Technical annex

WaterGAP 2.1 model (Water — Global Assessment and Prognosis) is the first global model that computes both water availability and water use on the river basin scale. WaterGAP, developed by the Center for Environmental Systems Research (CESR), University of Kassel, Germany, has two main components, a Global Hydrology Model and a Global Water Use Model. The Global Hydrology Model simulates the characteristic macro-scale behaviour of the terrestrial water cycle to estimate water availability. The Global Water Use Model consists of three main sub-models that compute water use for the domestic, industry and agriculture sectors. All computations cover the entire land surface of the globe on a 0.5 x 0.5 degree latitude-longitude grid. A global drainage direction map then allows the analysis of the water resources situation in all large drainage basins worldwide. For a more detailed description of the model see Alcamo and others (2000) and Center for Environmental Systems Research (2002). Note: Any discrepancies between the GEO-3 regions and sub-regions and the regions represented in data sets used to generate charts and other figures are noted with the individual graphics . Variables Variables charted or mapped in the Outlook section of GEO-3 are (in alphabetical order) as follows. Area with high risk of water-induced soil degradation indicates the land area that is at high risk from water erosion under a specific form of land use. The sensitivity to water erosion is computed from the soil and terrain characteristics, rainfall erosivity and land cover. In global terms, water erosion is the most serious form of land degradation and it is irreversible. Whether erosion actually occurs depends on implementation of soil conservation measures at farm and landscape levels. Source: IMAGE 2.2; Hootsmans and others 2001. For definition of erosion risk see UNEP/ISRIC 1991 Atmospheric concentrations of carbon dioxide presents the global CO 2 concentration in the atmosphere as the net balance between CO 2 emissions from fossil fuel combustion, industrial production, deforestation and CO 2 uptake by mature and regrowing vegetation, and by the oceans. Source: AIM for Asia and the Pacific; IMAGE 2.2 for other regions and global chart; De Vries and others 2001 Carbon dioxide emissions covers emissions from land use, industrial production and energy use. Emissions from industrial sources include the emissions from non-energy use of fossil fuels (mainly feedstocks) and industrial activities. Land-

GLOBIO (Global methodology for mapping human impacts on the biosphere) is a simple transparent global model developed under the GLOBIO project, coordinated by the Norwegian Institute for Nature Research (NINA), UNEP-GRID- Arendal, UNEP-WCMC and UNEP/DEWA. It is used to visualize, at a scale of 1 x 1 km, the cumulative impacts on biodiversity and ecosystem function of growth in human resource demand and associated infrastructure development. The model provides a statistical risk assessment of probability of human impacts using buffer zones from infrastructure that vary with type of human activity and density of infrastructure, region, vegetation, climate and sensitivity of species and ecosystems. Satellite imagery is used to derive overviews of cumulative impacts of ongoing development. Future scenario situations are derived from data on existing infrastructure, historic growth rates of infrastructure, availability of petroleum and mineral reserves, vegetation cover, population density, distance to coast and projected development. More information on GLOBIO can be found at http://www.globio.info and in UNEP 2001. IMAGE 2.2 (Integrated Model to Assess the Global Environment) is a dynamic integrated assessment model for global change developed by the National Institute for Public Health and the Environment (RIVM), The Netherlands. IMAGE quantifies the consequences of different future developments for a broad range of environmental issues. Driving forces are modelled for 17 world regions, partly via the WorldScan general equilibrium model. Impacts are calculated over long time frames (typically 100 years), and with a high spatial resolution (0.5 x 0.5 degree latitude-longitude grid). Long historical series are used to calibrate the model and place future developments in perspective. The model has been extensively reviewed and frequently used by the IPCC. More information about IMAGE is available at http://www.rivm.nl/image/ and in Alcamo and others (1998) and IMAGE Team (2001a and 2001b). PoleStar is a comprehensive and flexible software tool for sustainability studies developed by the Stockholm Environment Institute (SEI), Boston Centre, USA. Rather than being a rigid model, the software provides an adaptable accounting framework and modelling environment for mounting economic, resource and environmental information and for examining alternative development scenarios. PoleStar has been used in a number of international assessments, including quantification of the scenarios of the Global Scenario Group (GSG). Technical documentation on PoleStar and details of the GSG scenarios can be found online at http://www.seib.org/polestar and http://www.gsg.org

The quantitative results presented in this chapter were developed to illustrate the narrative scenarios and to provide an indication of their likely environmental implications. These results were derived using a range of analytical tools, in consultation with regional experts. They emphasize general trends and differences between scenarios, rather than precise levels of impact. This technical annex outlines the scenario development process followed for GEO-3 , and presents summary descriptions of the analytical tools employed, and the indicators presented in the chapter. More extensive information, including more detailed data tables and figures, is presented in Raskin and Kemp-Benedict (2002) and in a separate technical report (RIVM and UNEP, in press). The scenario development process Drawing from previous work of the Global Scenario Group (see Raskin and Kemp-Benedict 2002), four global storylines were designed by a core scenario team of global and regional experts. An initial quantification for a small set of indicators was prepared at the level of the GEO sub-regions. Teams in each of the seven major GEO regions then elaborated the storylines at regional level and provided input to the quantitative analyses, particularly with respect to key driving forces. The results of the regional efforts were used to refine the global narratives and to undertake the subsequent quantitative analyses associated with the scenario narratives. Further refinement of both the narratives and the quantitative analyses was achieved through an iterative process involving the core scenario team and the modelling groups. During the development process the work underwent two formal rounds of review and was scrutinized at a special workshop with a group of scenario experts from around the world. Quantitative analytical tools AIM (Asian Pacific Integrated Model) is an integrated environment-economy model developed by the National Institute for Environmental Studies (NIES) and Kyoto University, Japan, to assess future scenarios of socio-economic development and environmental change in Asia and the Pacific as well as at global level. The set of AIM modules was developed primarily for assessing effects of climate change policies and climate change impacts, but it can also be applied to other environmental fields such as air pollution, water resources, land use change and ecosystem assessment. With externally derived socio- economic data as input, the model estimates future environmental conditions of 42 countries in Asia and the Pacific. The ecosystem module uses a latitude-longitude grid with a spatial resolution of 2.5 x 2.5 minutes to facilitate policy analyses. The model has been extensively reviewed and frequently used by the IPCC. More information about AIM is available at http://www-cger.nies.go.jp/ipcc/aim/