Since Kapiti CALM was formed, we’ve consistently challenged the use of extreme climate scenarios such as SSP5-8.5 (formerly RCP8.5) in local planning, particularly the work of the Coastal Advisory Panel.

At the time we were told these scenarios represented the “best available science”. Yet we argued they were being misused for local planning because they were based on highly unlikely assumptions and exaggerated future emissions.

Now, even the lead developer of these scenarios for the IPCC has confirmed they should be regarded as “implausible”.

We recently wrote to the Minister of Climate Change/Local Government, as well as Kapiti Coast District Council, highlighting the latest updates to the IPCC’s position.

The Minister appears to have listened and has issued some instructions to Councils (you can read it HERE) . The real question now is:

Will our Council?

Will it continue relying on outdated, extreme assumptions that can affect property values, insurance, planning rules and public confidence? Or will it update its approach to reflect the latest science?

This is a pivotal moment.

Now is the time to contact your Councillors and ask them:

Will you commit to using the latest science and stop relying on implausible worst-case climate scenarios for local planning?

Knowledge is power, and we strongly encourage everyone to watch these outstanding interviews:

Unlikely Science:

▶ Part 1 – Detlef van Vuuren – Lead developer of the IPCC emissions scenarios and lead author of the paper concluding that SSP5-8.5 is now considered implausible.

▶ Part 2 – Roger Pielke Jr – Climate researcher who explains why this major shift matters, and what it means for climate policy and planning around the world—including here in New Zealand.

The science has moved on.

It’s time for local planning to do the same.

SHARE THIS IF YOU THINK IT’S TIME FOR AN UPDATE