[Coral-List] new "business as usual" projections for climate change

[Douglas Fenner]

Good points, thank you!
     I'm remembering now, that several people have pointed out that the
IPCC if anything has been overly cautious in its predictions, and we've had
a steady stream in the last several years of information coming out showing
that some things are worse than we though they were.  All backed by hard
evidence as well.
     Plus, there is the precautionary principle, and there has to be
planning for the possibility it will be much worse than the most likely
prediction.  Preparation is not just for 10 year floods but for 100 year
floods, and so on, lest you be caught in a disaster you're not prepared
for.  Unfortunately, that's been pretty obvious in some recent hurricanes
in the states.
     Cheers, Doug

On Thu, Feb 6, 2020 at 11:44 AM Arthur <webbarthur at gmail.com> wrote:

> Hi Doug,
>
> Thanks for sharing this link. This is important, not just to the
> mitigation discussions and targets, but also the adaptation discussion. I
> work at the pointy end of adaptation in the low lying atolls of the Central
> Pacific. Some consensus on what type of future we are preparing/designing
> for would indeed be helpful but I fear 9 times out of 10 the accountants
> are making that decision anyway, not the science.
>
> Whatever the case, my sincere advice out here is that we do adopt RCP8.5 /
> 2100 as our nominal adaptation horizon. Not because it can be perfectly
> argued but because it's a simple precautionary principle and driven by the
> local realities of adaptation needs, not the global politics and economics
> of emissions mitigation. For us sea level rise is our biggest immediate
> headache (of course closely followed by reef ecosystem demise - this is
> coral list after all) but if you look at the literature since IPCC AR5,
> (e.g. Le Cozannet et al 2019 *Low-End Probabilistic Sea-Level Projections*)
> RCP 8.5 SLR scenarios seem to be a real possibility. I'd be delighted to be
> shown to be in error on this but until then, we know what we know, and
> better to design for the worst end now whilst we still have the chance.
>
> SLR is climbing inexorably upwards, our region experiences higher rates
> than many parts of the world and many of our islands are extraordinarily
> low. 46% of the land area of the central part of Fogafale the capital of
> Tuvalu and home to the greater part of the national population, is already,
> during the highest measured sea levels since 1993 (I say again measured
> levels, not projected) below that figure. Now no one can argue this island
> was not always a finely balanced situation for its inhabitants and any
> perturbation in sea level has an effect. But sea level rise is now set in
> motion because of our emissions and its extremely unlikely to flatten out
> by 2100. All RCP values other than perhaps 2.6 (good luck with that
> ........) are problematic in these types of locations. For us, if it turns
> out we've over engineered by using a mid range RCP8.5 / 2100 horizon, it
> almost certainly means we've simply bought more time, protected from a
> bigger storm, we're better prepared for the next big drought - whatever it
> is its not wasted resources.
>
> Finally, the first thing I did when I read that paper was search for the
> words "methane" and "feedback". The authors do deal with this and I can't
> fault their thinking - I'm not likely qualified to. But neither am I
> convinced by their treatment of those issues. There is little doubt ones
> perception of those poorly understood feedback mechanisms and risks and
> ones subsequent willingness to leave them on the back shelf, will be
> coloured by whether you live, work and raise your family in a large better
> resourced developed economy or a small isolated atoll.
>
> Arthur
>
> Arthur Webb
> Senior Fellow - ANCORS
> University of Wollongong
>
> webbarthur at gmail.com
>
>
>
>
> On 05/02/2020 10:42, Douglas Fenner via Coral-List wrote:
>
> As we all know, global warming and acidification are huge threats to the
> future of corals.  Here are a discussion of some new insights into what is
> probable, if we don't take action.  Not quite as bad as had been projected,
> but still a "disaster" if we don't act.
>
> Cheers, Doug
> https://www.nature.com/articles/d41586-020-00177-3?utm_source=Nature+Briefing&utm_campaign=ee09f96136-briefing-dy-20200130&utm_medium=email&utm_term=0_c9dfd39373-ee09f96136-43423877
>
>
>

-- 
Douglas Fenner
Lynker Technologies, LLC, Contractor
NOAA Fisheries Service
Pacific Islands Regional Office
Honolulu
and:
Consultant
PO Box 7390
Pago Pago, American Samoa 96799  USA

"Already, more people die  <http://www.nws.noaa.gov/om/hazstats.shtml>from
heat-related causes in the U.S. than from all other extreme weather events."


https://www.npr.org/2018/07/09/624643780/phoenix-tries-to-reverse-its-silent-storm-of-heat-deaths


Even 50-year old climate models correctly predicted global warmng
https://www.sciencemag.org/news/2019/12/even-50-year-old-climate-models-correctly-predicted-global-warming?utm_campaign=news_weekly_2019-12-06&et_rid=17045989&et_cid=3113276

"Global warming is manifestly the foremost current threat to coral reefs,
and must be addressed by the global community if reefs as we know them will
have any chance to persist."  Williams et al, 2019, Frontiers in Marine
Science