Climate variability in social-ecological systems of the Southern Cape: integrating farming and fishing perspectives

Ward, Catherine Dale

Climate variability in social-ecological systems of the Southern Cape: integrating farming and fishing perspectives

Doctoral Thesis

2018

Abstract

Large scale shifts playing out on global climate levels are manifesting locally in the South Africa’s terrestrial and marine ecosystems, where it is difficult to predict how different habitats may respond to these changes in natural systems, particularly at local levels. For example, the highly complex nature of climate variability in the southern Cape and on the Agulhas Bank, coupled with the lack of long-term environmental monitoring data, has resulted in knowledge gaps on how climate impacts these local social-ecological systems. This thesis focuses on bringing together knowledge systems from farmers, handline fishers and local scientific weather sources to examine climate variability in terrestrial and marine social-ecological systems of the southern Cape, in order to bring local perspectives into conversation with scientific data outputs. Through examining different knowledge systems in parallel and overlaying different perspectives and observations, this thesis contributes towards a better understanding of complex systems change, linked through the common thread of climate variability under a resilience lens, at the local scale of the southern Cape and Agulhas Bank. This thesis also contextualises responses to change under the theme of climate variability from farmers’ and fishers’ perspectives, and shows how different theoretical discourses can work in a complementary fashion to address complexity. The terrestrial component of this thesis examined local agricultural perspectives by surveying southern Cape farmers, and built in terrestrial scientific data through looking at local climate in relation to farming perspectives. Observations on terrestrial rainfall and temperatures were collected through interviews with 50 farmers, along with shared rainfall records from 13 farming families and ten official weather stations in the area. Fisher perspectives in relation to climate variability were then integrated with marine scientific data to examine the marine component of the Agulhas Bank. Fisher observations of climate variability were examined by drawing on existing research conducted through the South Coast Interdisciplinary Research Project. Marine wind data were obtained through model outputs from NCEP-DOE Reanalysis and a recent scatterometer-based product. Overlaying these different bodies of knowledge reduced the uncertainties associated with any single set of observations and confirmed two environmental regime shifts in the region, in the mid-1990s and end-2000s. Local climate knowledge of farmers and fishers also overlapped and corroborated these environmental regime shifts. Changes in prevailing wind direction, rather than wind speed, were more prominent over time. While no clear trends of change over time were found in rainfall and temperature time series, decadal variability was present and after the mid-2000s, the onset of seasonal autumn rainfall was found to have shifted to a month later. Knowledge disconnects were broadly related to scale mismatches between fisher observations and marine data tendencies; complexities around freshwater availability; and shifting baselines of natural resources concerning present versus past variability observed by farmers and fishers. Responses to climate variability were complex and other stressors associated with economic and political challenges were usually seen as a greater threat to local livelihoods. However, climate stressors can push social-ecological systems into vulnerable states if not well integrated into adaptation strategies, which can have serious implications for future food and job security in the southern Cape. Local-based case studies such as this one increase understanding of local social-ecological systems under global change in an effort to contribute to future adaptation strategies in the southern Cape region.

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