A new global report has added weight to an urgent call from councils for more government support to help communities prepare for rising seas.
The report from the Organisation for Economic Co-operation and Development (OECD) found that, in most countries, local government groups were tasked with managing coastal risks from sea level rise, but under rules that were set at a national level.
It found that governments should do more to help communities prepare for climate change – echoing a message fired by Local Government New Zealand (LGNZ) last month.
The council lobby group's own recent report revealed as much as $14 billion of ratepayer-owned infrastructure was at risk of sea level rise – and recommended New Zealand set up a new national adaptation fund and risk agency to help councils address the problem.
The OECD report singled out Hawke's Bay's grassroots, 100-year plan as a good example for authorities around the world to follow.
The Clifton to Tangoio Coastal Hazards Strategy 2120 – a collaboration between councils, iwi and coastal community leaders – was designed to keep coastal planning and development across the region minimally exposed to climate-driven risks.
It underscored the importance of public consultation, coordinating plans and making decisions based on the best science and data.
Climate Change Minister James Shaw said it was likely that lessons learned in Hawke's Bay could offer solutions elsewhere in New Zealand.
"While each region and community will need to go through their own process to address their own circumstances, it's heartening to see that proactive models are now up and running, gaining traction, and drawing international attention as examples which other countries could use."
Yet one of the Hawke's Bay plan's key architects, Peter Beaven, felt the region was still ultimately operating in a grey area, "because there hasn't been any national alignment on responsibilities, resourcing or policy".
"As the report points out, 'The answers have not yet been developed in Hawke's Bay or anywhere else, and a serious conversation about our respective roles is long overdue."
LGNZ president Dave Cull argued there was a "huge deficit" of national support for coastal communities.
"Around the world, it's recognised that national plans are needed," Cull said.
"What we've been given in New Zealand is a guidance document that provides local government with limited direction, and as a result there's great uncertainty for our coastal communities."
"We are literally on the front line, and have been engaging with residents, iwi, and businesses who are exposed to rising sea levels, but the threat is too big for us to fight alone."
"As a country, we cannot continue to respond to climate change related events on a piecemeal basis."
In response to LGNZ's earlier report, Shaw said last month he was "acutely aware" of the threat that coastal communities faced.
The Government planned to push ahead this year with work to set up a new national risk assessment system.
"That work will also incorporate consideration of the very difficult issue of how we spread the financial burden of climate change impacts."
The LGNZ report showed that $2.7 billion of roading, water, and building infrastructure was at risk from as little half a metre rise in sea level.
The value of at risk infrastructure ramped up sharply at each increment of sea level rise, with the data showing that $5.1b worth was at risk at 1 metre of sea level rise, with $7.1b at risk at 1.5m and $14.1b at risk at 3m.
Under present projections, the sea level around New Zealand is expected to rise between 30cm and 100cm this century.
Climate change would bring more floods; worsen freshwater problems and put more pressure on rivers and lakes; acidify our oceans; put even more species at risk and bring problems from the rest of the world.
Climate change was also expected to result in more large storms compounding the effects of sea level rise.