I'm not at all suggesting that the possibility of serious sea level rise should be discounted. It exists and is clearly stated in the AR6 WG1 report, and various excellent publications. But they all make clear that it is not the most likely outcome and and keeping emissions on a path to below 2°C of warming will greatly enhance not just the likelihood that there is considerable time to plan. On the other hand, it is almost certainly both inequitable and unstable to force communities to plan for sea level rise that is still some way off or where it less than risks from seismic events or severe storms linked to atmospheric rivers linked to climate change. As Michael Mann likes to say, "the truth is bad enough. There's no reason to exaggerate it to make the case for urgent action." Denial groups concern me less at this point than reigniting doomerism unnecessarily.
In passing, it may be worth linking the first time I raised this as an emerging issue back in mid-2022. I didn't get full implications we're now seeing covered in this article, but tried... https://www.stuff.co.nz/environment/climate-news/129492959/an-unrealistically-hot-forecast-for-2100-could-hurt-your-property-values
Thanks Troy. There is discussion of this point in the guidance (Box 3 on page 41). They note
- SSP2-4.5 H+ reaches the same SLR just a few decades later than SSP5-8.5 H+.
- SSP5-8.5 H+ still not take into account the risks of further polar ice changes leading to more rapid SLR
- SSP5-8.5 is less likely than thought a decade ago, but still possible
- high-end impacts may still result from a lower emissions scenario
and several other points.
To which I would add that even a 17% tail-end risk (used in the H+ scenarios) is pretty high.
Dynamic Adaptive Pathways are recommended and discussed - I guess the question is whether this will lead to councils adopting them.
Meanwhile, councils are coping with organised climate denial groups pressuring them to drop the higher-impact scenarios.
I'm not at all suggesting that the possibility of serious sea level rise should be discounted. It exists and is clearly stated in the AR6 WG1 report, and various excellent publications. But they all make clear that it is not the most likely outcome and and keeping emissions on a path to below 2°C of warming will greatly enhance not just the likelihood that there is considerable time to plan. On the other hand, it is almost certainly both inequitable and unstable to force communities to plan for sea level rise that is still some way off or where it less than risks from seismic events or severe storms linked to atmospheric rivers linked to climate change. As Michael Mann likes to say, "the truth is bad enough. There's no reason to exaggerate it to make the case for urgent action." Denial groups concern me less at this point than reigniting doomerism unnecessarily.