Climate change adaptation demands attention

The world’s scientists tell us that climate change is already happening, so we will need to respond to the changes if we are to prosper in the future.

When we hear about climate change in the news, we mostly hear the causes of climate change and about how to reduce our impacts by restricting and reducing our greenhouse gas emissions over time. However, adapting to the physical impacts of climate change is important too.

The mouth of the Avon River at Sumner, Christchurch

What exactly is “adaptation”? Well, in the world of climate change language, it is the phrase used to describe the ability of people to cope with the physical impacts of climate change.

While policies to limit the causes of climate change, like the emissions trading scheme, aim to reduce carbon dioxide emissions in the longer term, adaptation is about coping with the challenges and taking advantage of opportunities presented by a changing climate.

As part of its portfolio of climate change work, the Ministry for the Environment has a programme to help local government and other stakeholders to better understand and consider climate change adaptation when carrying out their day-to-day operations.

In particular, the programme has developed guidance materials for local authorities to assist them in assessing and managing the risks of climate change in their strategic planning processes.

Environment Ministry General Manager Sue Powell says preparing for the physical impacts of climate change makes good sense.

“Adaptation is about risk management and being more resilient to current climate extremes like floods and droughts,” she said.

In 2007, the National Institute of Water and Atmosphere (NIWA) was commissioned to produce a second edition of two guidance manuals for local government called Climate Change Effects and Impacts Assessment and Coastal Hazards and Climate Change (both originally published in 2004). The second editions were commissioned following the release of the United Nations International Panel on Climate Change Fourth Assessment Report, with its updated findings on climate change, and the availability of new climate change information for New Zealand.

The updated Climate Change Effects and Impacts Assessment was officially launched at a stakeholder and media briefing in May. The manual provides the latest projections of the expected impacts of climate change, both at a national and regional level in New Zealand.

The second updated manual, Coastal Hazards and Climate Change, is also due to be released this year.

Powell says taking on board the information in these documents will help government, councils, businesses and communities to plan ahead to reduce the costs associated with the physical impacts of climate change and to take advantage of any opportunities they bring.

Of particular importance are infrastructure and developments that can be expected to cope with climate conditions not just now, but in 50 to 100 years’ time.

She says many organisations are already preparing for climate change, such as the Christchurch City Council, which is planning for the effect of sea-level rise on the Avon River.

An adaptation case study – the Avon River

Christchurch is the biggest New Zealand city to be built on a flood plain. As the climate changes, it is likely that Christchurch will face increased flooding in some areas, particularly around the lower Avon River and the area where it flows into the sea.

To address these concerns, Christchurch City Council undertook a study in 2003 to examine the potential effects of climate change on the Avon catchment and associated coastal areas and to assess how these risks could be managed.

While the stopbanks on the Avon flood plain currently provide adequate flood protection for most properties, in the future they are likely to be overtopped with greater frequency. This is due to the projected increase in the frequency and intensity of storms, storm surge, flooding and sea-level rise.

Options to reduce future flood risk

Heathcote River.

The 2003 report helped the council evaluate how climate change impacts could be integrated into risk management

planning for the Avon catchment and associated areas. It focused primarily on an economic analysis of likely damages, and the response options available to local government to mitigate the likely damage.

The report suggested that establishing minimum floor levels in buildings would be particularly the council considers setting different minimum floor levels for each floodable area of the city.

The option of improving flood stopbanks was also considered, but the report showed that stopbanks would only show an immediate benefit in one area.

Subdivision restrictions would not offer a net aggregate economic benefit in terms of preventing flood damages over the next 100 years, although the report said these may be worth considering in future.

Tidal barrages were considered unlikely to be feasible as they would not yield a net benefit and they would have considerable environmental and amenity issues.

Avon case study conclusion

Heathcote River in flood.

Since this report was undertaken, changes have been made to the council’s city plan and aspects incorporated

into its urban development strategy that seek to reduce the risks to the community from the physical impacts of climate change.

Powell says this type of response is exactly what the Ministry for the Environment wants to see happen across New Zealand.

“It is not a case of being alarmist it is simply getting people to use the scientific information available to minimise the risks and maximise the opportunities that come with the physical impacts of climate change.”

For more information see www.mfe.govt.nz/issues/climate/adaptation/ or email Stephen.Swabey@mfe.govt.nz or phone (04) 439 7462.

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