"New Zealand is planning for a climate future scientists now reject"

"New Zealand is planning for a climate future scientists now reject. And fixing it will require more than a policy tweak.

"New Zealand’s coastal climate change planning system is built on a simple legal standard: councils must plan for the likely effects of climate change, using the best available evidence [sic].

"[And] across the country, planning is being anchored to a future that scientists now say is implausible—and, legally, should never have been treated as 'likely' in the first place. [See story here.] ...

"[C]urrent guidance encourages planners to consider high‑end scenarios such as [the discredited] SSP5‑8.5. ... a scenario that IPCC lead author, and Canterbury University’s Professor Dave Frame, described as one 'no one believes.'

"In Kāpiti, modelling by consultants Jacobs Engineering—using high‑end assumptions based on SSP5‑8.5—identified thousands of homes as being at risk from coastal hazards. But when an independent review was undertaken by coastal scientist Dr Willem de Lange, using scenarios aligned with likely outcomes, the number of at‑risk homes fell to just 44.

"That is not a technical quibble. It is the difference between targeted risk management and large‑scale planning intervention affecting entire communities.

"Across New Zealand, similar approaches are being used by Councils to inform hazard mapping, LIM notations, and development restrictions. Tools like SeaRise continue to present projections derived from scenarios that no longer reflect what is considered plausible.

"Unwinding that system will be difficult.

"But leaving it in place is worse."

~ Sean Rush from his post 'New Zealand is planning for a climate future scientists now reject'