David Farrar: Councils should not use worst case scenarios for policy

Katharine Moody writes:

Not good enough, Simon Court. In a recent article, the Undersecretary for Resource Management Act (RMA) reform warned Councils that picking extreme climate scenarios in the conduct of regulatory decision-making “risks lawsuits by requiring developers to design and build to overly stringent climate warming models”.

By pulling out a yellow card, Simon Court assumes it will prevent further ‘screwing the scrum’ by over-zealous local experts and those local authorities who follow their guidance. In my experience as a consultant planner, it won’t be enough.

For years, I have observed a small group of local experts pushing the worst-case emission scenario, Representative Concentration Pathway (RCP) 8.5 from the Intergovernmental Panel on Climate Change (IPCC), on businesses and home owners across New Zealand.

And yes, councils have already been taken to court on this matter; and yes, the use of these extreme scenarios have already been found to lack scientific rigour on merit review.

The RCP 8.5 scenario is an extreme one. It assumes both that no country on earth implements any policy at all to lower greenhouse gas emissions, and that the impact is at the 90th percentile (ie the most pessimistic 10%).

Yet, her recommendations were largely ignored by the Ministry for the Environment (MFE) two years later in publishing its update to the Coastal hazards and climate change guidance for local government. This updated guidance recommended not only the use of the ‘high end’ RCP8.5 scenario, but additionally a ‘high end’ extreme of that extreme scenario, which they refer to as RCP8.5H+. The Ministry has further updated that guidance this year, still persisting with the recommended use of the ‘high end’ RCP8.5 scenario in coastal hazard planning.

RCP8.5 is the climate scenario that Professor Dave Frame, an IPCC lead author, describes in the article as “a scenario that nobody really believes in” ̶ except for, it seems, a small cohort of experts who appear to have secured undue influence on MFE.

To my mind, there is no remedy aside from expunging all reference to RCP8.5 from local government guidance and hence, from current planning practice. The cost to individuals, business entities and communities of ratepayers has been more than enormous already.

If Governments force developers to plan for a scenario that has no real possibility of occurring, the cost can run into the billions.

David Farrar runs Curia Market Research, a specialist opinion polling and research agency, and the popular Kiwiblog where this article was sourced. He previously worked in the Parliament for eight years, serving two National Party Prime Ministers and three Opposition Leaders.