With the UN climate talks now underway in Paris, the Herald's science reporter Jamie Morton is talking to a range of experts on climate-related issues.

Here he talks to Parliamentary Commissioner for the Environment, Dr Jan Wright, about a newly-released report which outlined New Zealand's vulnerability to sea level rise.

Q. Why was the report produced and what questions did it set it out to answer which hadn't been previously?

The intent was to increase understanding of how sea level rise will affect New Zealand, with a particular focus on the impacts on our coastal towns and cities.

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For the first time low lying areas around the country are accurately mapped in a standardised way.

This illustrates areas vulnerable to sea level rise.

Another purpose was to examine current efforts by central and local government to prepare for sea level rise.

The report identifies problems with, and gaps in, the direction and guidance provided by central government.


Q. What sea level rise can New Zealand, as a whole, expect over the coming century and how does climate change cause this effect?

Burning coal, oil, and gas releases carbon dioxide and this, along with other greenhouse gases, is warming the atmosphere.

As a consequence seawater is also warming and expanding, glaciers are retreating and ice sheets are melting, causing the sea level to rise.

The Intergovernmental Panel on Climate Change (IPCC) has projected that the sea around New Zealand will rise about 30 centimetres in the next 50 years.

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It is certain the sea will continue to rise for centuries to come.

What is uncertain is the rate of rise, especially later this century and beyond.


Q. What did the report identify as some of the most vulnerable parts of the country, and why?

In general, low-lying areas close to the coast are most vulnerable to sea level rise. But local factors are very important.

Cities with large areas that are particularly low-lying include Napier, Lower Hutt, Christchurch, and Dunedin.

The available data shows about 9,000 New Zealand homes lying less than 50 centimetres above spring high tide levels.

Accurate elevation data is not available for all towns and cities.

The report contains maps of Auckland, Wellington, Christchurch, and Dunedin showing the elevation of low-lying coastal land above the spring high tide mark.


Q. How under-prepared is New Zealand presently placed to face this threat, and why?

New Zealand needs to better prepare for sea level rise.

However the difficulty and complexity of this task is considerable.

This is partly because planning for sea level rise is outside our experience.

In most cases, there is time to make sure that we plan well and do not rush.


Q. What action, generally, needs to be taken both at council and Government level and what support is needed to make this happen?

In New Zealand, councils are responsible for planning for the impacts of sea level rise.
The Government has provided direction and guidance to councils.

I consider that central government needs to do more to help councils with this task and have found better direction and guidance is needed in three broad areas: scientific assessment of the impact of a rising sea on coastal hazards, the process of engaging with the community and the planning and management decisions that follow.


Q. What roadblocks do you see that might hamper this?

Preparing for sea level rise is a difficult task for councils and communities. Where should protective seawalls be built? Who will pay for them? Where should beaches be left to retreat inland?

When is abandoning maintenance of a coastal road justified? And when does the retreat of a whole community become inevitable?


Q. In the wake of the report, what feedback have you had from authorities and is there a willingness to make the improvements that you suggest?

I am pleased with the overwhelmingly positive response to the report.
In a statement, the Minister for the Environment, Dr Nick Smith, welcomed the report and said he had asked officials to carefully consider the findings of the report and its recommendations over the coming months.


Q. Planning measures in some parts of the country to address sea level rise, such as in Kapiti and Canterbury, have proven controversial with some residents. Do you feel New Zealand as a whole must change its perspective on this issue?

Councils and communities face a very difficult task in planning for sea level rise.
Perhaps the most difficult aspect is the impacts on people's homes, which for many are much more than financial security.

Councils must use science that is fit for purpose, and engage with communities in a measured way and with empathy.


Q. Comparatively, how do we stack up against other nations in terms of preparing for sea level rise?

The Shoreline Management Plans developed in the United Kingdom provide one model.
In each plan, the shoreline is divided into units.

Policies developed for the units include variations of "active defence", "managed realignment", and "no intervention".

I recommend that a similar approach be developed in New Zealand.


Q. In this context, how important are the climate talks now underway in Paris?

The talks in Paris are very important and I remain optimistic.

What the world, including our small country, does now will affect how fast and how high the sea rises.

Jamie Morton will be travelling to Paris with the support of the NZ Science Media Centre and the Morgan Foundation.