13 Feb 2019

The Cascade Effect: re-thinking climate resilience

From Nine To Noon, 9:27 am on 13 February 2019

A significant proportion of New Zealand’s population is under increasing threat from sea level rise; 300,000 residents live below three-meter land elevation.

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Photo: https://www.deepsouthchallenge.co.nz/

We're increasingly being confronted with climate change impacts such as drought, fire, and coastal flooding, but our responses to these changes are not keeping pace with the threat they pose, a researcher says.

Dr Judy Lawrence talked to Kathryn Ryan about two new pieces of pioneering research into climate change adaption. 

The first is around sea-level rise, with Hawkes Bay as a test case.

The second study looks at 'cascading catastrophes', when single events cause vicious downwards spirals.

The researchers say that understanding the impacts of extreme events, that have the power to cascade across all sectors of society, will make us more resilient when crunch time comes.

“Our focus is really on how do we make decisions today, thinking about tomorrow,” Dr Lawrence says.

“If we are to build a sea-wall, will it just create a safety net for people so that they forget about it and when it comes along we react?"

She says the research presented a range of options, from accommodation sea-level rises with seawalls and raising floor levels, right through to residents retreating from coastal areas.

The techniques the researchers used she says, were "adaptive pathways" combined with with more traditional methods such as "multiple criteria analysis" which is used routinely in New Zealand for thinking about hazard risk.

“But these hazards are changing, and they’re getting worse and they’re accelerating and so we want to be thinking about the consequences in the future for the actions that they take today.”

The studies looked at people’s assets – their homes and land – and presented them with the longer-term consequences of shorter term decisions. For instance, a seawall might keep their home protected for 10 or 20 years, but there will need to be another action before then too.

Dr Lawrence says the applications of their findings are fraught because there is a question as to whether local governments – and by extension, ratepayers – have the financial capability to act on these threats and it raises the question of whether there needs to be joint central-local government funding.

The second study, on cascading impacts, looked at how the effects of climate change might move through communities, through the economy and through the way New Zealand does business.

“To date, we’ve been very good at identifying individual hazards but when climate change comes along it exacerbates those and creates new ones.

“What the report does is highlight some of these in urban infrastructure situations and really identifies what the problem is. It’s more than just one hazard, two hazards, it’s multiple hazards at once which are propagating over time. If you pause for thought for a minute about an increased frequency of climate related events, this means that the recovery time is less. You come to a point when the system starts to break down, so we need governance structures.”

The current attitude of tackling incidents like major fires and storms as one-off events, and re-building and re-funding in time for the next one, is going to end, she says.

“We have to reframe what the problem is and because of that, we have to look at how our systems work, right through to the ability to anticipate these events and do something beforehand. In other words, to better plan for them and to avoid them.”