Australian State Ditches IPCC Predictions
THE state government of New South Wales will ditch UN sea-level rise predictions as the basis for coastal management, after local council decisions based on what climate change might do by the end of the century shattered waterfront property values.
The move, foreshadowed by The Australian in March, is likely to lead to renewed national debate on the application of long-term greenhouse effect forecasts to actual planning policy.
In an announcement today, the state government will say that climate change science is “continually evolving”, producing uncertainty surrounding sea level rise predictions.
The change follows an extensive review by a cabinet committee that re-examined the science of coastal processes.
It comes after revelations in The Weekend Australian owners of 62 beach-front properties at Lake Cathie on the NSW mid-north coast had suffered huge drops in the value of their homes after the Port Macquarie-Hastings council placed notations on their planning certificates saying they were at risk of coastal erosion. Another 17 home-owners at Lake Cathie had faced eviction, when a Snowy Mountains Engineering Corporation study recommended “planned retreat” in the face of erosion, a proposal later rejected by the council.
Lake Cathie was one of 15 coastal erosion “hot spots” on the NSW seaboard identified by the former Labor government.
Local councils covering those areas are in varying stages of developing coastal zone management plans, and have been required by laws introduced by Labor to take into account sea-level rise predictions of the UN Intergovernmental Panel on Climate Change.
These laws compelled coastal councils to prepare for a forecast sea-level rise of 40cm by 2050 and 90cm by the turn of the century.
Planners apply a formula known as the Bruun Rule, which estimates that every centimetre of sea-level rise will bring the tide a metre inland based on a standard beach, leading to coastal erosion.
Special Minister of State Chris Hartcher will announce a new coastal management policy that would free councils from having to rely on the IPCC predictions.
In a statement, Mr Hartcher says “the heavy-handed application of Labor’s sea-level rise planning benchmarks for 2050 and 2100 would go”.
“The NSW Chief Scientist and Engineer has identified uncertainty in the projected rate of future sea-level rise given that the scientific knowledge in the field is continually evolving.”
Based on the long-term IPCC predictions, the Port Macquarie-Hastings council in 2008 placed “Section 149″ notations on houses at Lake Cathie warning they could be subject to coastal erosion, although they are separated from the beach by a 60m-70m strip of bushland and are nine metres above sea level.
The notations had caused property values to fall by an average of 44 per cent based on sample valuations of four houses.
“There has been concern about the negative impacts on property values from these unclear Section 149 certificate notations,” Mr Hartcher says in the statement.
The NSW government would issue advice to all councils to guide the preparation and use of section 149 certificates.
“This will provide much-needed certainty for local communities on how these certificates refer to future coastal erosion hazard,” the statement says.
The government will announce further changes to coastal management policy. Councils preparing coastal zone management plans will be given an extra 12 months to complete them.