Browsing by Author "Midgley, G"

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    Economic impacts of climate change in South Africa: A preliminary assessment of unmitigated damage costs
    (2002-02) Turpie, J; Winkler, H; Spalding-Fecher, R; Midgley, G
    This study aimed to provide a preliminary desktop estimate of the economic impacts of climate change in South Africa, based on the findings of the Vulnerability and Adaptation Study for the South African Country Study on Climate Change (1999). Damages are those predicted for 2050 and are valued in year 2000 rands, unless otherwise stated. Predicted impacts from this study include changes in terrestrial and marine ecosystems which will have profound impacts on agriculture, forestry, rangelands and fisheries, as well as on biodiversity. In addition, changes n hydrology may have immense consequences in terms of human health by increasing suitable habitat for waterborne diseases, as well as affecting water supply and the maintenance of ecosystem functioning. Prediction of the economic impacts of climate change is particularly difficult because of the global scale of the impacts and the long time horizon involved. Such studies have mostly been carried out in developed countries, and often only concentrate on market impacts such as agriculture. Impacts are typically divided into market and non-market impacts, with ecosystem and health damages relegated to the latter category, but this study recognises that all impacts have their basis in changes to natural systems, and that all types of impacts have both market and non-market components.
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    Impacts, vulnerability and adaptation in key South African sectors: an input into the Long Term Mitigation Scenarios process.
    (Energy Research Centre, University of Cape Town, 2007) Midgley, G; Chapman, R; Mukheibir, P; Tadross, M; Hewitson, B; Wand, S; Schulze, R; Lumsden, T; Horan, M; Warburton, M; Kgope, B; Mantlana, B; Knowles, A; Abayomi, A; Ziervogel, G; Cullis, R; Theron, A
    Ten free-standing chapters make up this report, and this Executive Summary and supporting Synthesis Report serve to draw together the main findings in both an abbreviated and an extended and illustrated format that focuses on main findings, but also adds a level of detail for the purpose of communicating the key results, and the uncertainties associated with them, for the benefit of a policy maker. The chapters that make up this report are compiled as separate documents as follows. These are generally reviews of the literature available, but in some cases comprise new work that has been carried out to provide information in an area that is lacking an assessment.
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    Water relations, carbon fixation and growth rates of two leaf succulent species under different water regimes
    (1988) Beukman, Ruth Pam; Stock, W D; Midgley, G
    The leaf succulent species R.carolii and R.multiflora are common in the winter rainfall Karoo. Despite their similar growth form, their distribution in Worcester Veld Reserve appeared to differ. R.multiflora occupied a more exposed, arid North - facing slope, while R.carolii dominated a protected South facing slope. Possible reasons for this distribution were investigated. Plants of the two species were established in a growth chamber and subjected to different water regimes. The diurnal patterns of water loss and ca1rbon gain were investigated under optimal and drought conditions after 30, 50 and 60 days of treatment. Gas exchange data of both species showed that C3 photosynthesis was adopted when ·the plants - were irrigated regularly, but also tended to accumulate malate, which indicated the activity of RuBPc and PEPc. R.carolii had higher photosynthetic and growth rates than R.multiflora under optimal conditions. This explained the dominance of R.carolii on the South facing, protected slope. Under moderate water stress, the species behaved similarly. There was a tendency towards CAM activity, though results were inconclusive. During periods of extreme water shortage. R.carolii exhibited limited stomatal response and thus appeared to be dying, while R.multiflora adopted day time stomatal opening a and CO2 uptake. This strategy and in general the high tolerance to water stress shown by R.multiflora allowed it to outcompete R.carolii on the arid, exposed, North facing slope.