The Herald has obtained the documents after a five-month freedom of information battle with the council.
The council released the documents after a confidentiality agreement with the Department of Planning lapsed.
The council’s environmental systems manager Quentin Espey said the documents were made for a presentation to councillors 10 months ago to raise awareness of the need to adapt to climate change.
The council made the maps with airborne laser technology data, provided by the Department of Planning, to assess areas vulnerable to future sea level rise.
Dr Espey said sea level rise would be an “extremely gradual process, happening at about one centimetre a year”.
“There are ways to hold back water, such as using seawalls, that we will have to consider in the near future,” Dr Espey said.
The documents show four scenarios of sea levels rising by 0.53metres, 0.88metres and 1.4metres by 2100, and six metres by 2500.
The two lower levels were based on mid-range and high-range scenarios predicted by the Intergovernmental Panel on Climate Change (IPCC), the world authority on the subject.
The 1.4-metre scenario was based on a comparison of pre-industrial age data with the IPCC’s future warming scenarios.
The six-metre rise scenario was based on climate scientist Jonathan Overpeck’s predictions, which featured in Al Gore’s award-winning film, An Inconvenient Truth, and Tim Flannery’s book The Weather Makers.
Dr Espey said it was based on half of the Greenland ice sheet and half of the West Antarctic ice sheet melting, but that was predicted to take 300 to 500 years.
Under the 0.53-metre scenario, 2800 lots or 750 hectares would be vulnerable to inundation.
The lots include developed and vacant land.
With a rise of 0.88metres, 4700 lots or 1300 hectares would be under threat of being permanently flooded, and a rise of 1.4metres would place 8500 lots or 2400 hectares in danger.
A six-metre rise would leave 18,000 lots or 6500 hectares under threat.
THE MAPS
The maps below show the consequences of a 0.88-metre rise in sea levels, as contained in Lake Macquarie City Council documents.
Red areas on maps show land under threat from sea levels.
Under four possible scenarios, the following threats would apply:
Rise.............Lots threatened..Hectares..Year
0.53 metres.........2800.............750.......2100
0.88 metres.........4700............1300......2100
1.4 metres..........8500.............2400......2100
6 metres............18,000...........6500......2500
Note: Land shaded red near the coast and waterways will be most vulnerable to rising sea levels. Inland areas shaded red will be under threat from increased rainfall and storm surge caused by climate change.
 |  |  |  |
News and politics
climate change
No comments:
Post a Comment