MEDIA RELEASE
NO. 192/2008
09 MAY 2008


CITY PLANS FOR GLOBAL WARMING AND RISING SEA LEVELS

An in-depth study into the predicted impact of rising sea levels on the City’s coastal line development is being undertaken by the City of Cape Town.

At a meeting of the Planning and Environment Portfolio Committee (Pepco), councillors were presented with three different scenarios as to how changes in tidal movements and increased storm events may impact on rising sea levels. The modelling was done to determine the possible impact on the City’s infrastructure.

"The aim of the Sea-Level Rise Risk Assessment is to predict the ramifications of sea-level changes as a result of climate change on existing coastal systems. This will help guide coastal development and enable the City to develop long-term adaptation measures for high risk areas," says Cllr Brian Watkyns, Chairperson of Pepco.

"With over 307 km of coastline, the City of Cape Town has the longest stretch of sea frontage of any metropolitan authority in South Africa. As such, it is particularly vulnerable to global climate change predictions which will result in amongst others, a rise in sea levels and an increase in the intensity and frequency of storm events," he says.

"The predicted implications of climate change were modelled based on existing information and internationally accepted predictions of future scenarios. The model portrays what could be expected as current day worst case storm events, increased storm intensity and frequency as a result of climate change within 10 years and finally the long term inundation implications if the Antarctic and Greenland Ice-sheets melt.

According to Gregg Oelofse of the City’s strategy and planning department, the model made use of data from the extreme storm event experienced along the KwaZulu Natal coast in March 2007.

"The erosion damage in KZN was spectacular and similar damage should be anticipated along exposed sections of the Cape Town coast in similar circumstances. The identification of these vulnerable sections of the Cape Town coast is an important output," he says.

The second scenario predicts the situation at the end of the next decade after an acceleration in sea level rise in the frequency and intensity of storms as well as a slight increase in the mean sea level. Rather than being a ‘very worst case’ which only occurs once every half a century, scenario two can be expected whenever an extreme storm occurs at the same time as any fortnightly spring high tide in the spring or autumn. As extreme storms are expected to become more frequent, this scenario is a realistic rather than an unusual event for the end of the next decade.

The third scenario entails the ‘wholesale melting’ of the Greenland and West Antarctica Ice Sheets which is anticipated to greatly contribute to sea level rises and coastal inundation. There is uncertainty about the extent and the timing of the melting of these polar ice sheets, however the implications for the city would be an increase of up to 20m in the mean sea level.

"What the sea-level rise risk assessment shows is that the implications of climate change for our coastline are significant. Impacts will be experienced across key service infrastructure such as wastewater treatment works, stormwater pipelines, electricity grids and substations as well as roads and rail routes. In addition, residential property and recreational amenities located in the coastal areas are particularly vulnerable" says Oelofse.

The key purpose of the study is to identify the risks and by so doing begin to plan adaptation and mitigation strategies to minimise the implications of climate change. What the model does clearly show is that if we do not proactively address Climate Change, the outcomes and implications for the city will be severe and potentially catastrophic in the long term.

Examples of some of the high risk areas presented to the portfolio committee in Cape Town were those situated mainly in low lying areas or close to estuaries and include Milnerton Lagoon, Fish Hoek, Strand, Gordon’s Bay and Sea Point.

Pepco will work closely with the new Energy Committee in developing climate change mitigation and adaptation strategies for the City as well as taking this initial sea level rise model further to better understand the full implications of climate change across the entire city.

The sea-level risk assessment will also feed into the City’s draft coastal development guidelines, which is currently being discussed by the various Sub-councils, and which have already highlighted the need for preserving a coastal buffer in all coastal areas that have not yet been developed.


END

ISSUED BY:
COMMUNICATION DEPARTMENT
CITY OF CAPE TOWN
TEL: 021 400 3719

MEDIA QUERIES:
CLLR BRIAN WATKYNS
PEPCO CHAIRPERSON
TEL: 021 531 7601 CELL: 083-444-4807

TECHNICAL ENQUIRIES:
GREGG OELOFSE
TEL: 021 487 2239 CELL: 083-940-8143