Research conducted by the cities of Cape Town and Durban indicates that the consequences of rising sea levels are far greater and far-reaching than was previously believed, and predicts huge knock-on effects and cost.

A prior assessment done by the International Panel for Climate Change(IPCC) concluded South Africa's coastal vulnerability was not significant, but new research points to potentially catastrophic scenarios resulting from temperature changes and the disintegration of ice sheets.

Speaking at the Climate Justice Conference being held on the Project 90x2030 Goedgedacht farm outside Malmesbury, development economist, Anton Cartwright, said much of South Africa's coastal development has been "imprudent".

As the coast is deemed one of the country's greatest assets it has seen rapid development, exacerbating its vulnerability.

While wealthy South Africans, who occupy most coastal property, have and will continue to experience the bulk of the direct risks of rising sea levels (such as storm surges that degrade natural buffer areas) there are numerous secondary or indirect risks that threaten the greater population.

Cartwright listed potential scenarios such as disruptions in goods and service delivery, high insurance premiums, strains on disaster relief and governance, and psycho-emotional ill-health.

Direct risks include physical tidal force resulting in loss of life, infrastructure, heritage and real estate, during periods of extreme high-tide.

A rise in sea level of 2.5 metres, which has a projected likelihood of 95 per cent by 2100, has a threaten value of R5.2 billion attached to it.

He said it was now acknowledged that "even small increases in sea-level profoundly truncate the return times of extreme storm surges, and that climate change itself may be making these storms more intense and frequent".

The better news was that South Africa is in line with the global mean, which meant global research is applicable to the country and made "planning a bit easier".

Cartwright said as it stood, decision makers were unsure about which of the range of possible interventions to implement and how to "make difficult trade-offs in the context of sea level rise uncertainty".

He said the most effective form of sea level rise reduction involved the enforcement and protection of a coastal buffer zone, as proposed in the Integrated Coastal Management Bill (2007).