Research Outputs (Geography, Archaeology and Environmental Studies)

Permanent URI for this collectionhttps://wiredspace.wits.ac.za/handle/10539/20147

Browse

Start date: 2006Subject: search.filters.subject.climate change

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Projections of rapidly rising surface temperatures over Africa under low mitigation.
    (Institute of Physics Publishing, 2015-08) Engelbrecht, F.; Adegoke, J.; Bopape, M.-J.; Naidoo, M.; Garland, R.; Thatcher, M.; McGregor, J.; Katzfey, J.; Werner, M.; Ichoku, C.; Gatebe, C.
    An analysis of observed trends in African annual-average near-surface temperatures over the last five decades reveals drastic increases, particularly over parts of the subtropics and central tropical Africa. Over these regions, temperatures have been rising at more than twice the global rate of temperature increase. An ensemble of high-resolution downscalings, obtained using a single regional climate model forced with the sea-surface temperatures and sea-ice fields of an ensemble of global circulation model (GCM) simulations, is shown to realistically represent the relatively strong temperature increases observed in subtropical southern and northern Africa. The amplitudes of warming are generally underestimated, however. Further warming is projected to occur during the 21st century, with plausible increases of 4-6 °C over the subtropics and 3-5 °C over the tropics by the end of the century relative to present-day climate under the A2 (a low mitigation) scenario of the Special Report on Emission Scenarios. High impact climate events such as heat-wave days and high fire-danger days are consistently projected to increase drastically in their frequency of occurrence. General decreases in soil-moisture availability are projected, even for regions where increases in rainfall are plausible, due to enhanced levels of evaporation. The regional dowscalings presented here, and recent GCM projections obtained for Africa, indicate that African annual-averaged temperatures may plausibly rise at about 1.5 times the global rate of temperature increase in the subtropics, and at a somewhat lower rate in the tropics. These projected increases although drastic, may be conservative given the model underestimations of observed temperature trends. The relatively strong rate of warming over Africa, in combination with the associated increases in extreme temperature events, may be key factors to consider when interpreting the suitability of global mitigation targets in terms of African climate change and climate change adaptation in Africa.
  • Thumbnail Image
    Item
    Resilience of small-scale societies: a view from drylands.
    (Resilience Alliance, 2016) Gomez-Baggethun, E.; Salpeteur, M.; Puy, A.; Biagetti, S.; Scheffran, J.; Balbo, A.L.
    To gain insights on long-term social-ecological resilience, we examined adaptive responses of small-scale societies to dryland-related hazards in different regions and chronological periods, spanning from the mid-Holocene to the present. Based on evidence from Africa (Sahara and Sahel), Asia (south margin of the Thar desert), and Europe (South Spain), we discuss key traits and coping practices of small-scale societies that are potentially relevant for building resilience. The selected case studies illustrate four main coping mechanisms: mobility and migration, storage, commoning, and collective action driven by religious beliefs. Ultimately, the study of resilience in the context of drylands emphasizes the importance of adaptive traits and practices that are distinctive of small-scale societies: a strong social-ecological coupling, a solid body of traditional ecological knowledge, and a high degree of internal cohesion and self-organization.