Debate over Dunedin sea level rise figures – In the News

Houses in South Dunedin are at risk of sea level rise, but there has been debate over figures suggesting thousands of homes could be affected by 2034.

Emeritus Professor Jim Flynn told the Dunedin City Council on Monday that parts of the city could have just 17 years before sea level rise makes them uninhabitable. He was responding to a report that pumps to clear water would be needed in South Dunedin by 2040 and told councillors the issue would come to a head before that.

He said his prediction was based on a NASA formula showing sea level rise was 7.2mm in 2014 and 8.5mm in 2015 and said at that rate there could be 25cm of sea level rise by 2034.

However, climate change researchers have disputed the claims.

Victoria University of Wellington’s Professor Tim Naish told Newshub that Prof Flynn was “right to be raising the issue as a real concern, but I have a little bit of concern that his numbers are slightly on the high side, or very much on the high side”.

University of Otago’s Associate Professor Nicolas Cullen told the Otago Daily Times that the figures were “questionable”.

“I agree that there is evidence that the two large ice sheets [Greenland and the Antarctic] may contribute more to sea-level rise in the future than previously thought, but I would think it is very unlikely that South Dunedin will be under 5m of water in 2090.”

Global sea level rise for 2014 and 2015 was about 3.5mm, Prof Naish told Radio NZ, not the more than 7mm in the data NASA presented. The most credible projections still predicted a 30cm rise by 2050-60, he said.

The claims and counter-claims have been covered by local media, including:

Otago Daily Times: Academic warns of sea threat
Newshub: ‘Thousands’ of Dunedin homes to be lost to rising sea
Radio NZ: South Dunedin could sink below sea level in 17 years
Otago Daily Times: Flynn’s sea level figures disputed