Sea levels will rise 30cm around New Zealand by 2050 and threaten coastal properties and infrastructure in low-lying areas, a new report by Government’s environment watchdog warns.
Parliamentary Commissioner for the Environment Jan Wright’s report, released this afternoon, says rising oceans caused by a warming atmosphere will have a significant impact on many New Zealanders within their lifetimes.
Dr Wright looked at around 200 years of scientific study of sea levels for the peer-reviewed report.
She said three factors were causing ocean levels to rise - seawater expanding as it became warmer, retreating glaciers, and shrinking ice sheets in Greenland and Antarctica.
Her report said sea levels around the world had risen 20cm in the last 100 years.
Drawing on research from the Intergovernmental Panel on Climate Change (IPCC), the commissioner warned of a further rise of 20cm to 40cm by 2050. This would occur regardless of action taken on reducing greenhouse gas emissions, meaning New Zealand would be forced to adapt.
“A rise of 30cm may not sound like much, but its impact will be very costly for many landowners,” Dr Wright said.
The impacts of a rise in sea level were most evident during storm surges, when wind and waves piled up water against the coast.
The commissioner said a storm surge in downtown Auckland in January 2011, which flooded roads, homes and shops, was worse than a similar size storm in 1936 because the sea level was 11cm higher.
