In 1996, the IPCC began the development of a new set of emissions scenarios, effectively to update and replace the IS92 scenarios. The approved new set of scenarios is described in the IPCC Special Report on Emission Scenarios (SRES) ( IPCC 2000 ). Four different narrative storylines (A1, A2, B1, B2) were developed to describe consistently the relationships between emission driving forces and their evolution and to add context for the scenario quantification. Each emission scenario represents a specific quantification of one of the four storylines, and all scenarios based on the same storyline constitute a scenario “family”. The resulting set of forty scenarios (thirty-five of which contain data on the full range of gases required for climate modelling) cover a wide range of the main demographic, economic and technological driving forces of future greenhouse gas and sulphur emissions. None of the emission scenarios explicitly assume implementation of the UN FCCC or the emissions targets of the Kyoto Protocol. However, greenhouse gas emissions are directly affected by implementation of policies designed for a wide range of other purposes. Furthermore, government policies can, to varying degrees, influence the greenhouse gas emission drivers, and this influence is broadly reflected in the storylines and resulting scenarios. Graphical description of SRES Scenarios is depicted in Figure 8 .
Published in Chapter:
Climate Change Impact on the Water Resources of the Limpopo Basin: Simulations of a Coupled GCM and Hybrid Atmospheric-Terrestrial Water Balance (HATWAB) Model
Berhanu F. Alemaw (University of Botswana, Botswana) and Thebeyame Ronald Chaoka (University of Botswana, Botswana)
Copyright: © 2018
|Pages: 24
DOI: 10.4018/978-1-5225-3440-2.ch012
Abstract
This chapter aims to evaluate the impacts of climate change on both hydrologic regimes and water resources of the Limpopo River Basin in southern Africa. Water resources availability in the basin, in terms of, seasonal and annual runoff (R), soil moisture (S) and actual evapotranspiration (Ea) is simulated and evaluated using the hydrological model, HATWAB. These water balances were computed from precipitation (P), potential evapotranspiration (Ep) and other variables that govern the soil-water-vegetation-atmospheric processes at 9.2km latitude/ longitude gird cells covering the basin. The 1961-90 simulated mean annual runoff reveals mixed patterns of high and low runoff across the region. Although relatively small changes in runoff simulations are prevalent among the three climate change scenarios, generally the OSU simulated relatively high runoff compared to the UKTR and HADCM2 GCMs.