The Risks from Sea Level Rise - assessments from Australia & Cape Town

Reuters reported today on an Australian parliamentary committee’s finding that $137bn worth of property in this island continent was at risk from rising sea levels and more frequent storms. 80 percent of Australia’s 21 million people live on the coast and authorities are split on whether to adopt a policy of retreat or defence against rising seas.

The social and economic impact of sea level rise was the topic at our recent Cambridge Resilience Forum session (get the podcast here). A 2008 risk assessment done for the City of Cape Town concluded that within the next 25 years there is an 85% probability of 60,9km2 (2% of the Metro area) being covered by sea for a short period, with an accompanying expected loss of real estate value estimated at just under R20bn. As Prof Geoff Brundrit explained, these estimates are predicated on only a 15 centimeters rise in the sea level. Even such a relatively small rise changes the frequency and intensity of extreme storm events and this causes the damage. A more dramatic sea level rise, when the polar ice caps melt for example, causing coastal areas to be underwater permanently, is not even included in current estimates for the next 30-50 years.

Gregg Oelofse of the City of Cape Town elucidated some of the challenges for government. The possible mitigation strategy of building more storm walls and barriers can actually increase the impact of storm events. The Cape Town study done in 2008 was one of the first in the world and has placed the City on the forefront of planning and thinking about these issues.

Similar to the Australian report, the Forum session also highlighted the importance and complexity of legal liability and insurance cover related to climate change and sea level rise. At the Cape Town event Herman de Meyer, underwriting specialist of Santam, emphasised that insurers need to collaborate with scientists and policy makers to better understand these risks.

The 16 October edition of Engineering News carried an article on the sea level rise Forum session. Read the online article here…