Coasts and Oceans
The vulnerability of the coastal zones of South Africa to Climate Change - compiled by Dr. Alan Aldrin Meyer, CSIR, email@example.com
The rapidly changing global climate due to anthropogenic induce global warming does not only impact on atmospheric weather systems, but is also altering the circulation of the global ocean, which in turn feeds back to atmospheric circulation. The change in ocean circulation due to climate change will impact the goods and services normally derived from coastal zones. Not knowing at what pace and how this change will manifest might make coastal nations vulnerable in regards their food security, energy security and national security. Currently efforts are underway in South Africa to predict changes to the circulation of atmosphere and ocean due to climate change. The ability to predict future environmental events that may impact negatively or positively on a country’s gross domestic product will be of great advantage to its national security as this will enables high ranking decision makers to plan and adjust national budgets accordingly. Allocation of water, food and energy resources could then be rationed according to what is predicted, affording better mitigation and adaptation. This ability will in the end analysis contribute to the overall welfare of the country’s socio-economic standing and will be of great help especially in Africa where the threat of rapid climate change will hit earth’s most vulnerable citizens, the hardest.
The coastal zone of South Africa consists of the oceanic region between the coastline and the 200 m isobath (the continental shelf edge). This region is markedly influenced by the two large scale ocean currents on either side of South Africa, i. e., the Agulhas Current along the east and south coasts and the Benguela Current along the west coast. Theoretical, observational and numerical studies all show that the large scale current systems around South Africa will change in their average positions in the next 50 years and will thus impact on the physical properties and circulation of the coastal zone. This in turn will impact on the coastal zone flora and fauna, and those communities that derive their livelihood from coastal zone goods and services.
The National Biodiversity Assessment (NBA) 2011 follows the first National Spatial Biodiversity Assessment (NSBA), led in 2004 by the South African National Biodiversity Institute (SANBI). The NSBA 2004 was the first comprehensive national spatial assessment of the state of biodiversity, covering terrestrial, freshwater, estuarine and marine environments. It introduced two new headline indicators for assessing the state of South Africa’s biodiversity: ecosystem threat status (referred to as ecosystem status in 2004), and ecosystem protection level. Ecosystem threat status tells us how threatened our ecosystems or habitats are, and ecosystem protection level indicates how well- or under-protected our ecosystems or habitats are. For the first time, these indicators were comparable across aquatic and terrestrial environments. The primary purpose of the NBA is to provide a regular high-level summary of the state of South Africa’s biodiversity, with a strong focus on spatial assessment. The NBA is intended for decision-makers both inside and outside the biodiversity sector. It feeds into and links with other policy-related processes such as state of environment reports, identification of threatened ecosystems for listing in terms of the Biodiversity Act, the National Protected Area Expansion Strategy, and the National Biodiversity Strategy and Action Plan.
Both observational data and global climate models show that the Indian Ocean is warming up due to global warming. The warming is however geographically specific, with most of the warming concentrated along 40 degrees south latitude. Affiliated with the warming is an off-equatorial subsurface cooling. Observations and model results show that these climatological changes are due to many intertwined factors. The lack of observational data and downscaled climate models for the South Western Indian Ocean, and especially for the Agulhas Current Region east of South Africa, will impact on our ability to assess the consequences of global warming on regional coastal ecosystems and regional climate robustly. There is every reason to expect climate change impacts to reflect in changes in the fisheries of the region. Effects will manifest due to changes in biogeography of target species and the distribution of their larval stages. Productivity of offshore and coastal waters will be impacted by changes in circulation as well as fluvial runoff patterns, and thus the trophic basis for some fisheries is likely to be effected. Climate change impacts on coral reefs, mangroves and seagrass beds will also result in major changes to fisheries. Clearly this will have impacts to the region's economy and its people.
"In order to fulfill the requirements of the United Nations Framework Convention on Climate Change (UNFCCC), South Africa has prepared an Initial National Communication to the UNFCCC, in accordance with Article 12 of the Convention. In addition, detailed South African Country Studies reports have been compiled on a sectoral basis. Using the results of this work, together with information from the IPCC Third Assessment Report, the Department of Environmental Affairs and Tourism has developed a national climate change response strategy."
"The oceans are warming. Over the period 1961 to 2003, global ocean temperature has risen by 0.10°C from the surface to a depth of 700 m." "Large-scale, coherent trends of salinity are observed for 1955 to 1998, and are characterised by a global freshening in subpolar latitudes and a salinification of shallower parts of the tropical and subtropical oceans." "Key oceanic water masses are changing; however, there is no clear evidence for ocean circulation changes." "Global mean sea level has been rising. From 1961 to 2003, the average rate of sea level rise was 1.8 ± 0.5 mm yr–1. " "Ocean biogeochemistry is changing. The total inorganic carbon content of the oceans has increased by 118 ± 19 GtC between the end of the pre-industrial period (about 1750) and 1994 and continues to increase."
Links to Governmental Departments, Tertiary Institutions, Councils, and Organizations related to coastal zones, oceanography and climate change
The South African governmental departments, tertiary institutions, councils and organizations related to coastal zones, oceanography, and climate change are listed here.
Internet links to other marine atlases, data bases, libraries, websites, science journals and programs.