Recording of Dr Peter D. Ward: Sea level change: How bad, how fast? HPAC Thu March 7
rob...@rtulip.net
The recording of the HPAC conversation today with Dr Peter D. Ward on Sea Level Change is at https://youtu.be/YjwacAjHsHU
This discussion covers vital information for Earth’s future.
Dr Ward’s slides are temporarily here.
Participant comments included input from sea level expert Dr John Englander as well as dialogue on the potential of solar geoengineering to mitigate sea level rise.
Dr Peter Ward is Professor of Palaeontology at the University of Washington. He is co-author of the influential book Rare Earth: Why Complex Life is Uncommon in the Universe, and is a leading expert on the causes of mass extinctions (see his TED talk, my review of Under a Green Sky).
Robert Tulip
https://www.healthyplanetaction.org/
Healthy Planet Action Coalition
rob...@rtulip.net
Dear Peter
Thank you very much for your superb presentation and discussion.
Our community of interest in HPAC supports the triad of direct climate cooling, GHG removal and emission reduction.
One of the themes that arose in the discussion on your information on the likelihood of severe impacts from sea level rise is that nothing we can do about carbon can affect the risk of several metres of SLR this century, destroying all low lying coastal infrastructure and agriculture, but there is significant potential for albedo increase to mitigate the rate of inundation. Increasing planetary reflectivity would require concerted attention to the safety and feasibility of various methods proposed, which unfortunately are the object of strong disinformation campaigns.
This point about albedo potential has not been adequately appreciated in policy discussions, especially regarding the security and misery impacts.
Your slide 42 linked in my email below provides estimates of effectiveness, timeliness, safety and affordability for main climate interventions. I don’t think it is at all accurate as regards efforts to deal with sea level rise, given the primary role of albedo in mitigation potential.
Your suggestion to engage on advocacy is very welcome, for example finding media willing to cover this important topic, sharing well-crafted messages. One theme we are discussing is the need to rebrighten the world, as discussed at rebrighten.org.
Best Regards
From: Peter D Ward <ar...@uw.edu>
Sent: Friday, March 8, 2024 10:53 AM
To: rob...@rtulip.net
Cc: Healthy Planet Action Coalition <healthy-planet-...@googlegroups.com>; Planetary Restoration <planetary-...@googlegroups.com>; geoengineering <geoengi...@googlegroups.com>; Healthy Climate Alliance <healthy-clim...@googlegroups.com>; JOHN ENGLANDER <johneng...@gmail.com>
Subject: Re: Recording of Dr Peter D. Ward: Sea level change: How bad, how fast? HPAC Thu March 7
Thank you all for your attention and you patience in my many areas of ignorance especially about engineering. I learned a great deal and want to help going forward.
I will write an Op Ed. I hope it is of quality that you will sign on. We need to do more. I need to do more
robert...@gmail.com
Hi RobertT
This was one of the best sessions we've had. Thanks so much for setting it up.
As regards your comments below, can you point me to where in the recording either David or Peter said that there was significant potential for albedo increase to mitigate the rate of inundation. When I asked the direct question as to what, from an Earth Science perspective, could be done to relieve SLR, my recollection is that neither offered an answer. I came away with the strong impression that they were saying that significant SLR is already baked in and there is absolutely nothing, including SRM, that can be done in the short to medium term to arrest it. This interpretation might just be a perfect example of confirmation bias on my part, so I'd really like to get this point clear.
Perhaps in response to this message, either
Peter or David could clarify. The question is, from an Earth
Sciences perspective and ignoring engineering, economic and
political dimensions, what could now be done to stop or reverse
the SLR that is already in train?
Robert
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Robert Tulip
Robert C, my comment on albedo potential to mitigate sea level rise was about the discussion from you, Mike MacCracken, myself and others. You are right that Peter Ward and John Englander did not say SRM can mitigate SLR. Peter expressed strong doubts about the safety of SRM. I have previously discussed this with John Englander who as I recall commented that the political barriers make SRM unrealistic.
I agree this was one of the best HPAC sessions, and encourage others to watch it (link). It provides great impetus to understand the security and humanitarian dimensions of climate responses.
Noting email discussion on how SLR relates to CO2 and temperature, I attach a graph I made from NOAA data of sea level and insolation over 300,000 years. This illustrates that orbital temperature variation was the primary systemic driver of natural climate change. CO2 level changed in response to northern summer insolation and then amplified the global climate impact through dust, albedo and other feedbacks. The millennial lag between insolation and sea level is clearly apparent. This strongly indicates that to slow sea level rise, reflecting more sunlight is our only option.
Also attaching two of Peter Ward’s slides that merit discussion.
The first slide extrapolates SLR estimates to 2300, and looks to have lower rise than John Englander suggested in his book Moving to Higher Ground, where he says “forecasts now predict sea level rising as much as eight feet this century, with even further increases considered possible.” P6
The second slide interprets a range of climate options in terms of cost, effectiveness, safety and speed, from the 2009 Royal Society report on Geoengineering (Figure 5.1. Preliminary overall evaluation of the geoengineering techniques considered in Chapters 2 and 3). My sense is that many of these judgement calls are highly contestable and are well worth debating.
Regards
Robert Tulip
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rob...@rtulip.net
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