March 03, 2022

Misinformation about Sea Level Rise

There are few environmental issues with more unsupported claims than the effects of global warming on sea-level rise.  

And such incorrect information is particularly egregious here in the Pacific Northwest.

One of the worst offenders is the Seattle Times, which published a problematic story this week.   A story that was internally inconsistent, full of obvious errors, and making claims that are hyperbolic at best.


The Seattle Times claims include (all direct quotes):
  • The Washington coast could see as much sea-level rise — 4 to 6 inches — in the next three decades as it did in the previous century.
  • By the end of the century, the state could see nearly 3 feet in average sea-level rise, according to the new projections, a jump from 2 feet in past studies.
  • King County is expecting 2 to 3 feet of sea-level rise — and up to 5 feet — by 2100.
  • Seattle has seen more than 9 inches in sea level rise since 1899 based on measurements by a NOAA tide gauge located at Colman Dock, according to King County. The new report estimates it will see about that much rise by 2050.
None of these claims is remotely true.

Important note: The Seattle Times article, the referenced NOAA report, and this blog talks about Relative Sea Level, sea level relative to the land.  That level is what counts for impacts.  Global sea level or absolute sea level is another thing entirely, and that is rising everywhere as the Earth warms.  The absolute sea-level rise, as shown by the U.S. EPA, has been about 8 inches over the last century (see plot below).


Observed Sea Level Changes in the Pacific Northwest

NOAA has an excellent site that provides access to sea-level observations.  Below is a map from their website, which shows that sea-level trends are not uniform over the region, with SEVERAL LOCATIONS SHOWING SEA LEVEL DROPPING, NOT RISING. (blue arrows indicate sea level is falling)

I repeat dropping.  And for the remainder of the region, many of the sea level increases are very modest (the size of the arrows are the same for a wide range of trends).


Why are so many areas showing sea levels falling?  

Because the land is rising, for two geological reasons.   One is called isostatic rebound;  the land had been pushed down by the last glaciation and is still rebounding, causing sea level to drop.  And the movement of the San de Fuca Plate under the North American Plate is causing portions the Pacific Northwest to rise (see USFS figure below), resulting in sea level either falling or rising to a lesser extent.



 So we have some geological protection here in the Pacific Northwest.  You don't hear about that in the Seattle Times or by certain climate activists.

Now consider one of the few locations on the Washington Coast with rising sea levels: Toke Point.  Here is the plot of sea level over its record starting in the mid-70s.   

Barely rising at all.  At this site, there is no acceleration in sea level rise during the past decades as the Earth has warmed.   None. Zip. Nada.


With sea level DECLINING at most coastal locations in the Northwest and a tepid rise at places like Toke Point, this claim by the Seattle Times is obviously incorrect:

    "The Washington coast could see as much sea-level rise — 4 to 6 inches — in the next three decades as it did in the previous century.



A Longer-Term Look at Historical Sea Level Rise in Puget Sound (and King County)

The largest sea-level increase in the region is at Seattle,  so let's examine its observations next (see below).  The record at Seattle is a very long one...going back to 1900!

Sea level in Seattle has risen at a very steady rate over the past 120 years: by approximately 2.06 mm a year or 8.1 inches per century.   There is no hint of acceleration of the upward trend, even with global warming.  

And importantly, the steady upward trend over the past 120 years suggests that human-forced global warming is NOT the cause, since the impacts of human emissions have only been appreciable for roughly the past 50 years.


If the current rate of increase holds, sea level will rise by 2.4 inches in Seattle by the year 2050, a far cry from the 9 inches claimed by the Seattle Times.

And Seattle is the great outlier for the western interior.  The sea-level rise at Victoria is ONE-THIRD as large, so the increase in sea level will be less than an inch by 2050.


Bellingham is rising even more slowly:  by about .32 mm a year (1.16 inches per century)


I can show you more, but you get the point.   Sea level in the Northwest is either nearly steady or falling on the coast, and rising very slowly in the interior.  Based on past and current trends, and the absence of any acceleration of the sea level rise, the sea level rise over the next few decades should be modest at best.

A very minor problem at worst.  You would think that the energetic, inquisitive reporters at the Seattle Times would check what has happened to sea level before they wrote the article, and provide readers the needed perspective.  They did not.

The NOAA Report

So where did the Seattle Times come up with all those excessive sea level rise projections? 

They quote a new NOAA report.  This report has a number of technical issues and problems.  For example, a key Table (2.2)  of the report claims that in the Northwest, extrapolation of observed sea-level rise trends would bring a 0.16-meter rise between 2000 and 2050.  That would be 6.3 inches.  As demonstrated above, that number is wildly in excess of the actual trends, which would result in zero rise on the coast and perhaps 0.5 to 2.5 inches in the western interior.


And somehow the Seattle Times increased that problematic 6.3 inches to 9 inches.  I should note that this NOAA report uses unrealistic global warming predictions based on unphysical increases in fossil fuel use to get the big estimates of sea-level rise that some folks like to talk about.  Some of the numbers quoted in the Seattle Times article--as much as a 5 ft rise in King County by the end of the century--are pure fantasy.

The Bottom Line

  The Northwest, like in so many ways, is highly favored to experience far lesser impacts of anthropogenic global warming than many locations.   Our rising land is one reason.  The slow warming of the eastern Pacific and favorable ocean currents is another.

The Seattle Times article had substantial and obvious errors and attempted to make a very benign situation appear dangerous and threatening.  This is not responsible journalism.  

A Plea

Please don't leave comments calling me names (e.g., skeptic, denier, Trumpite, or worse).  If you don't like my analysis tell me where I got the numbers wrong.  Global warming is a serious issue that requires that all of you are well informed so that you can elect representatives that will take practical, realistic actions (such as restoring forests and encouraging more nuclear energy).  I have spent some time noting the frequent exaggerations and misinformation of the Seattle Times because the flagship regional newspaper should be doing far, far better.




36 comments:

  1. What a cool map from NOAA! I'm happy to be in Seattle - zoom out and look at the globe... not so good for the East Cost, Europe, Asia. I think the Dutch, with their land reclamation tech, will do well for themselves in the next century, providing tools to protect areas that do see sea level increases due to global warming. Could the sea level reductions in Scandinavia and Alaska also due to the "isostatic rebound" you mentioned?

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  2. The Seattle Times article has as an authority on the consequences - -
    "Ian Miller, a coastal hazards specialist with
    Washington Sea Grant of the University of Washington."

    Where do the out-sized rise numbers come from? RCP8.5?
    The paper should express shame and close down.

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  3. Now I’m wondering what’s the reference for sea level. I’d want to say that land level is rising faster than sea level without that being a sea level drop as such. Or is it really dropping, but if so relative to what other reference?

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    1. Sea level doesn't have anything to do with "land level". If a fixed reference on land rises relative to the sea, that doesn't mean there is more or less water in the sea! Regardless, the quantity of liquid water in the sea is what worries people. There is only one way for this quantity to increase - that is for the amount of solid water on the planet to decrease, ie, melting ice.

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    2. There is also the thermal expansion of the water. Same number of molecules take up more space when warmed.

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  4. Love your articles. Thank you! In this case, I do think that your interpretation of landmass rise off base. Just because the rise off the land outpaces the rise of the ocean doesn’t mean that the ocean isn’t rising. Also, isn’t it possible / likely that The Cascadia Earthquake will eventually remove those rises in the landmasses? Regardless, thank you for your analyses and perspective. It’s great having a source of weather and climate info that I can trust.

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    1. Thanks bb12. My blog, the Seattle Times article, and the NOAA plots are relative sea level, sea level with respect to the land. In contrast, there is absolute sea level, which is rising everywhere. Based on your comments and that of jlundell, I have added that information to the blog. Glad you mentioned this...want to be very clear about what I am showing.

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    2. Isn't bb12's essential point that land-rise is a *periodic* function---a slow rise, then a sudden drop, a slow rise, a sudden drop, and so on? I don't know the odds off-hand for the next Cascadia subduction-zone earthquake over 80 years, but it could well be 50/50 odds by 2100. It is good that your post distinguishes between absolute and relative sea level, but if the land level can reasonably be expected to fall by the end of this century, doesn't that impact the truth/falsity of the relative-sea-level projections?

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    3. That's a good distinction to make, but if the land level can reasonably be expected to sink again by century's end (at the next Cascadia earthquake), doesn't that have some bearing on the truth/falsity of the relative-sea-level projections? It would be helpful if you stated how much of the land rise is due to isostatic rebound (which isn't going away) and how much is due to the bending of the Pacific Plate (which will). As written, a reader might reasonably assume that the land is rising monotonically upwards---which of course is not how it works.

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  5. Thanks for the information Cliff.
    Do you consider the gradual loss of snowpack to be the biggest problem for the Pac NW due to global warming?
    It seems like we in the NW would be wise to develop more water storage capacity.

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    1. Cliff did an extensive piece on this a year ago entitled "The Northwest Snowpack Trend of the Past Fifty Years: The Truth May Surprise You" - https://cliffmass.blogspot.com/2021/03/the-northwest-snowpack-trend-of-past.html

      I agree with you we should develop more water storage capacity, but only for the consistency and management capabilities that go with it.

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    2. Can't recall the year, but when the Green River last went dry one fall Tacoma Water was pumping 10 gallons/sec. out of a small deep lake in the watershed into the river for the salmon. A larger reservoir is needed there, since most of the watershed snow is gone by the time lawn irrigation season hits. Same with the Yakima, which has high mid summer drawdowns. I hope it never gets as bad here as the lower Colorado basin, which is just a brackish drainage water dump! Our rivers still flow to the sea, thank God!
      NorWester

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    3. "lawn irrigation season". We need a cultural change. Watering lawns needs to not be a 'thing'. Every summer my grass (what's left of it), turns to a golden dust, but always, always, always comes back greener and thicker than ever. In fact, I need to weed wack it this weekend. It doesn't die, but goes dormant instead. Plant natives and don't water your grass. Good for people, animals and fish all around.

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    4. The "cultural change" you are advocating for Blake would be highly damaging to our city. People in Seattle - whatever their water usage - pay for their water. They pay a city tax - on top of what they pay the utility - that is 15%, one of the highest city taxes on anything (and into the general fund). Water is not cheap here: in fact the last national study I saw had Seattle as the 2nd most expensive city in the nation for water.

      Would you prefer that instead of us having 30 billion gallons of water left over in our reservoirs (like we did last year, for which once again the media lied that we were in a drought), we had 40? To be flushed - along with the tens of millions of dollars that otherwise would have been raised by the city to improve it - to make room for the fall rain and winter/spring snowmelt inflows? The stats on water inflows and consumption are readily available at SPU: https://www.seattle.gov/Documents/Departments/SPU/Services/Water/WaterSupply_02-28-2022.pdf

      SPU is one of the most forward-thinking national utilities on protecting fish and resources. Their water managers are top notch. We have bountiful water supply here, a huge watershed (thank you city leaders 100+ years ago with that foresight), and good infrastructure.

      So again: why do you want to eliminate that large, annually renewable source of revenue for the city, and what basis do you have for it?

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    5. sunsnow 12- the past 50 yrs snowpack trend does not help with what is coming for the next 50 years.
      The projections are for much smaller and more variable snowpack as the century unfolds. And the population, hydroelectic, and agricultural demands will be much higher- you can bank on the fact that more people are going to migrating north to this region, as the colorado, sacramento and san joaquin basins get hotter and drier, and thus with less snowpack.

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    6. Right, so for the last 25 years we have been hearing exactly this, and for a decade (plus), no one could refute it because the predictions were always far "in the future".

      But now we can. So the prediction in 2001 that "snowpack would be halved by 2015" is now provably wrong. The prediction in 2007 that "Cascade snowpack is collapsing" and "ski areas would be closed by 2020" is now provably wrong. And I could go on and on.

      Now all that is left is the name-calling, which thank you for not resorting to. But these predictions have zero credibility now to anyone who has followed this subject for 25+ years.

      The lying and dishonesty on snowpack and drought (and I am not pointing to you, I agree with you on building more storage and respect your opinion) has been overwhelming. But I hope we can also come together to reject the constant disinformation. It needs to stop.

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    7. Sunsnow12
      Can you tell us who made these claims, provide links for this info you are quoting please.

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  6. Thanks Cliff, when I saw this NOAA map last night I was going to you ask how much tectonic action vs global warming when I saw rises in some areas vs falls in others. Seems kinda obvious, but I guess not all will think "oh yeah the plates are always shifting." Thanks for keeping it real and educating those who listen. Now I am sure this would be hard to measure, but you speak about the rebound, as the weight shifts from ice on land to water at sea, how much will the pacific plate actually get pressed down mitigating the catastrophic rises they speak of? It's like a 1, 2 thing. Land with ice rises back up, seems like the ocean floor should get pushed down too.

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    1. Rising sea level will cause isostatic loading and downward movement. That movement is one of many challenging factors sea level modelers deal with as itvaries greatly from place to place.

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  7. How is the rising of the land in the PNW mean sea level is dropping? If I jump up on a trampoline, I will get higher but the level of the trampoline stays the same.

    Sea level can still rise but if our land is rising faster then the effect of sea level rise here is blunted but it doesn't mean it's going down. Do you mean 'relative' sea level?

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    1. 'Relative' sea level is exactly what the blog states, as compared with 'absolute' sea level which he states is rising at roughly 8 inches per century.

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  8. Would you like to view a "young" San Juan Islands? If so, visit the Beardslee Islands in Glacier Bay Park and Wilderness. They are a great example of isostatic rebound.

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  9. Brilliant post Cliff.

    There are a lot of folks offering up all kinds of "facts" on this and related other topics, with each side picking their preferred "experts" as proof of their version of the truth.

    The best thing to do is to read (actual books). There's a wealth of knowledge from people who are truly informed, many of whom have dramatically opposing views on these subjects.

    One very simplistic book, easy to read, is: "An Inconvenient Truth". You can find it on Amazon...it's 120 or so pages. Those that have strong opposing views will find some of the discussions too simplistic, others will simply dismiss them offhand.

    I'm not smart enough to know the answers but, I found it very interesting.

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    1. OMG, I'm getting old....the book I wanted to refer to was: "Inconvenient facts" (Author: Gregory Wrightstone).

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  10. What about Tacoma and Olympia? Past predictions I've read have been relatively significant for the south Sound.

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  11. "There are few environmental issues with more unsupported claims than the effects of global warming on sea-level rise. And such incorrect information is particularly egregious here in the Pacific Northwest."

    I'm thinking here you could start a number of your blog subjects with that statement and be 100% accurate.

    But imo there has been nothing that has come close to the snowpack or the drought lies. Nothing. The lies are constant (every year), have been going on for over twenty years, and are repeated by multiple agencies, NGO's, utilities and media outlets - all who have gained in power and $$$ from this false narrative.

    We've had "mother nature conspiring against us." We've had "wet droughts" (2015). We've had scientists straight-up fired for presenting contrary evidence to the "collapsing Cascade snowpack" theme (2007). We've had "couldn't keep a straight face when those summer rains came" and "upping the crisis mentality for the good of the state". And those are just off the top of my head. Btw, those last two: from Seattle Public Utilities in the admitted bs of 2001 when they put in one of the largest percentage price increases for water in Seattle. And what did it appear they learned from that whole thing?: 1) don't ever tell the public again you couldn't "keep a straight face" (Seattle followed up in 2003 and 2005 with two more... but no more public comments) and 2) the drought narrative really, really works.

    It's about time for your annual (I can set my watch by it now) "no, actually Cascade snowpack is stable and in some places increasing" blog entry or the "no we are not in a drought and will not be" discussion. Just consider starting it this year with "There are few environmental issues with more unsupported claims than..." :)

    Thank you as always for being a scientist Cliff with the courage to state the truth, there are not a lot left.

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    1. As usual, sunsnow12 brings a needed voice of reason (especially when it comes to snow pack). Thank you. :)

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  12. Is there a reason Seattle's relative water level is going up especially much? Maybe land still sinking from being built up with fill dirt? More intense/frequent winds pushing water up Puget Sound or into Elliott Bay?

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  13. If you haven't yet, check out the NOAA sea level data viewer that Cliff recommends: https://tidesandcurrents.noaa.gov/sltrends/
    You can see all of the actual data, including plots over time for specific locations. As always, the devil is in the details. Coastal PNW, especially Alaska is in great shape, but man I'd hate to be living on the Gulf in TX or LA where the sea level is rising at a rate of nearly 1 cm per YEAR!

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  14. Cliff has it only partially correct. Tides gages measure eustatic sea level rise and deep subsidence (or uplift), but not the shallow subsidence processes that happen between the depth of the post that a tide gage is mounted on, and the the sediment surface. So, technically, relative sea level rise = ESLR + deep subsidence + shallow subsidence. Unfortunately, because much of our coastline is diked and drained former estuary, we have high rates of shallow subsidence behind the dikes, thus exacerbating relative sea level rise. This is why it is becoming more difficult to drain land adjacent to dikes and why some farmland nearest the dikes is being abandoned. When you live or farm at right mean high high water, or below, it really is a matter of inches.

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  15. Thank you for your integrity and for providing actual facts and analysis to help us understand the world we inhabit.

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  16. Cliff, just a note to commend you on a very clean, clear, well researched and well cited post.

    Keep up the good work!

    w.

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  17. "Such as restoring forests and encouraging more nuclear energy"

    Great points Cliff. I have been trying to raise awareness with the forest issue with local outdoor organizations in the community but they seem set on wildfire prevention with little scope for controlled burning and restoring healthy forests. As an avid outdoors person I see first hand the state of the forests as I hike through them. Regardless of climate change they're a tinderbox ready to go up in flames once the soil dries out. Any thoughts on how we can convince officials on taking these practical measures?

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  18. "So we have some geological protection here in the Pacific Northwest." Enjoyed your positive take on the Cascadia Fault protecting us from sea level rise! However, that only applies to the outer coast and be aware it is ephemeral protection. Much of that uplift and relative sea level lowering will be lost when the fault next shifts.
    Within the Salish Sea lowlands the story gets complicated as there are several cross (east to west) faults and associated sub basins that influence local relative sea level. For example the south end of Bainbridge Island has been uplifted exposing a broad platform of former tide land. Other areas have lost elevation.
    In regards to rebound from glacial ice loads and isostatic rebound, that factor is not relevant to western Washington. Western Washington bounced back very rapidly and essentially rebounded by about 7,000 years ago (see Haugerud, R.A., 2020 (figure 4), Deglaciation of the Puget Lowland, Washington, in Waitt, R.B., Thackray, G.D., and Gillespie, A.R., eds., Untangling the Quaternary Period—A Legacy of Stephen C. Porter: Geological Society of America Special Paper 548, p. 279–298, https://doi.org/10.1130/2020.2548(14).) Other areas with stiffer crust are still rebounding (Scandinavia, Hudson Bay) and that is one driver of sea level rise in addition to rising temperatures.

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  19. In a comment above, bb12creek said: "Also, isn’t it possible / likely that The Cascadia Earthquake will eventually remove those rises in the landmasses?"

    As humans, we experience both slow moving disasters and very fast moving disasters.

    An example of a slow moving disaster is our public policy of shutting down a good portion our supply of fossil fuel electricity without having anything in the way of a credible plan to replace it.

    An example of a very fast moving disaster will be the next Great Northwest Earthquake whenever the Cascadia Fault a hundred miles off the coast of Oregon and Washington breaks loose and delivers The Big One right to our doorsteps.

    From Wikipedia: The last known great earthquake in the northwest was the 1700 Cascadia earthquake. Geological evidence indicates that great earthquakes (> magnitude 8.0) may have occurred sporadically at least seven times in the last 3,500 years, suggesting a return time of about 500 years. Seafloor core evidence indicates that there have been forty-one subduction zone earthquakes on the Cascadia subduction zone in the past 10,000 years, suggesting a general average earthquake recurrence interval of only 243 years. Of these 41, nineteen have produced a "full margin rupture", wherein the entire fault opens up. By comparison, similar subduction zones in the world usually have such earthquakes every 100 to 200 years; the longer interval here may indicate unusually large stress buildup and subsequent unusually large earthquake slip."

    The Cascadia Fault currently has about thirty-nine feet of displacement locked into it. An earthquake as strong as 9.0 on the Richter Scale is therefore possible. Portions of the Northwest coastline dropped ten feet the last time fault popped loose.

    Whenever I visit the Northwest coast on business or for a short vacation, I carry a survival bag just in case the Cascadia Fault decides to let loose while I'm in the area.

    The bag has extra clothes including a silk-screened T shirt I bought at Cannon Beach in Oregon: "Tsunami Evacuation Plan: grab beer, run like hell."

    That plan will work well enough if you happen to be in Cannon Beach when the fault breaks and you know where the evacuation routes are. But if you are living and working in Portland or in Seattle, and the worst of what can happen inside a large city in the course of a major 8.5 or 9.0 earthquake, there will be no place to hide.

    One thing is certain when the next Great Northwest Earthquake hits -- the Seattle Times will blame it on climate change.

    ------------------------
    Disclosure: I post as 'Beta Blocker' on WUWT and on Judith Curry's blog. I use Betah Blocher here on the Cliff Mass blog because the commenting system doesn't allow 'Beta Blocker' as a valid user name.

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  20. As Cliff points out at the top of his post, he addresses things "here in the Pacific Northwest".

    For anyone curious about sea level rise in other parts of the contiguous U.S. or wanting to see what will happen in the Pacific Northwest in the future, this link has a nice interactive map showing what will happen as glaciers continue to melt.
    (Antarctic glaciers - sea level rise

    The bottom of that page has a link to a discussion of "postglacial rebound" that discusses how changes in the earth's shape result in regional differences in sea level rise.

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Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

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