Climate Deniers: Sinking Fast

When it comes to sea level rise, climate deniers are desperate.

It’s so obviously happening that denying its reality is a loser. It’s so obviously costly already (half a billion dollars in Miami) that trying to deny that will only prove that they’re not interested in reality. Sea level rise has gotten so out of hand, even climate deniers are worried about it (but for all the wrong reasons).

That’s why they keep trying the stupidest excuses imaginable to blame it on something — anything — other than global warming of course. The part which is both fascinating and disturbing is that, however moronic their claims, their followers are gullible enough to believe ’em.

Case in point: in a recent post I suggested that Roy Spencer move, together with his climate denial, to Miami Beach. This prompted a reader who is gullible enough to believe nonsense to comment:

Pardon me? Miami Beach? That pice of land where SUBSIDENCE is waaaay bigger than SLR? C’mon.

He’s just repeating some truly stupid bullshit, which makes him look truly stupid.

I guess he’s unaware that we have sea level data which is unaffected by land movement: the satellite data. It doesn’t measure relative sea level as tide gauges do, which depends on the height of the sea surface and the height of the land. It measures sea surface height directly.

We can compare the tide gauge data from Miami (Virginia Key is the closest station which is up-to-date) and the satellite data. The difference between relative sea level (from the tide gauge) and sea surface height (from satellites) estimates how the land has moved. And … what do we find? Here’s the satellite data for the ocean near Miami Beach (in blue) and the tide gauge data (in red):

It certainly doesn’t look like land subsidence is “waaaay” bigger than sea level rise.

We’ll get a better idea if we subtract the tide gauge data from the satellite data. This will estimate the vertical land movement, and I’ll remove the seasonal cycle to make things even clearer. The result:

According to the trend line (in red) the land is indeed sinking, but not very fast. We can calculate how fast the sea surface is rising, and how fast the land is sinking. The result (how fast sea surface height is rising, compared to how fast the land surface is subsiding):

Two things are clear. First, it’s not certain that the land is actually sinking. The rate suggest that it is, but the uncertainy (as indicated by the error bars) shows that result is uncertain. Second, even if the land is sinking, subsidence is definitely not “waaaay” bigger than sea level rise. It’s smaller — and that result holds even when allowing for the uncertainty associated with the trend estimates.

So where did he get his nonsense? “Trump University”?

I regularly get such comments from climate deniers. I moderate them out, because this blog is not a forum for climate denier bullshit. But from time to time, I use such comments to demonstrate just how stupid climate denier bullshit is. So keep ’em comin’! If you want to spend your time composing idiocy for this blog, only to see it disappear into the void or, better yet, provide fodder for demonstrating your folly, please do. And thank you.

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8 responses to “Climate Deniers: Sinking Fast

  1. this plays out in a couple of ways. Some of the deniers are like your “subsidence” guy, they are just not very smart and have an ideological drive to reject the science. Another section of the denier group is smarter than that, but is so dedicated to the culture wars that they keep moving the goalposts to avoid having to admit they have been and are so wrong about so many aspects of global warming. Anyone who posts in good faith at the decent scientific blogs on global warming (like this one) knows both of these types. The first group doesn’t stick around long when their “science” is emphatically rejected. The second group posters won’t go away and enjoys wasting the time of folks who want to talk about the science and impacts in an honest manner.

    I read through these days, but I feel pretty disconnected from the global struggle to address the warming because the apocalyptic triumph of the republican party has made progress so difficult. Truth and science are inconvenient truths, which is to say, they have become gore-memes and the hateful, xenophobic nationalism that is arising around the globe appears to have too much appeal to our species. As the planet becomes less hospitable to its inhabitants and climate refugees multiply, our dominant/mainstream political response appears to be moving towards walls to keep the outsider out instead of a mobilization to rescue and support folks who have already been displaced.

    I expect that as denial becomes too difficult to manage, the focus will turn to hateful xenophobic nationalism. But, as you note, denial is becoming more difficult. Too many people can no longer disbelieve their eyes. Seeing is believing for a lot of folks with little scientific training and stories like subsidence can only hold up for so long.

    So, what is the solution? What’s a sane and compassionate person to do? I think:
    1. Don’t engage with the folks who post in bad faith. Identify them quickly as the provocateurs that they are and ban them from comments. These folks serve no useful purpose in the discussion. Dis-emvowelling them works fine.
    2. Engage with the folks like your “subsidence” guy to see if he/she/they can be educated and understand the science better, but keep this brief. A lot of bad faith posters love playing this game, they get something out of it, but the advancement of scientific understanding in the general population is likely slowed by the work of and with these folks.
    3. Talk frankly and openly about the need to engage with the science and consider rational and compassionate public policy responses to a building crisis. Call out the culture warriors for fueling hatred and oppression, but do that quite briefly and then get back to the science discussion and creating a platform conducive the imagination of rational and compassionate public policy.
    Remember that what we give our attention to, we will get more of. Endless engagement with intransigent ignorance makes very little sense.

  2. Interesting. I would have expected the rate of subsidence in Florida to be higher. But now that I look, it seems consistent with the general consensus science. E.g., Sweet et al., Fig 5, from, shows GPS-derived land movement rates, and it seems like southern Florida is mostly in the 0-1 mm/year subsidence range (in contrast to the mid-Atlantic, with subsidence rates of 2-4 mm/year, or the Gulf Coast of Louisiana & Texas with subsidence rates of 3-5 mm/year).

    Note that an overall rate of subsidence of <1 mm/year does not necessarily mean that subsidence can't play larger localized roles: one poster ( suggests that localized subsidence variation could be up to 4 mm/year between the highest & lowest rates in Miami. But even the highest localized rates of subsidence shown in the poster are <3 mm/year, so still less than the rate of increase of sea surface height…

    • I think a leading cause of subsidence in Florida is depletion of groundwater, so we are really looking at ocean encroachment on developed property created by two different anthropogenic causes. Time to sell and move to higher ground?

  3. Land subsidence along the Atlantic coastline of the US has been studied at high resolution in some critical areas (e.g. Miami Beach and Norfolk, VA) using Differential Synthetic Aperture Radar Interferometry; see Chapter 4 of this book. From the Conclusions:

    Global SLR is the main source of the increased flooding hazard along the low-lying coastal communities, such as the Atlantic regions of U.S. In these areas, flooding hazard can also be enhanced by relative SLR accelerations given by land subsidence…localized subsidence affected the city of Miami Beach in particular along the western coastal area, where the city was built over reclaimed land 80-90 years ago. The subsidence rates are in the range of -1.6 mm/yr – 3 mm/yr…

    and, in the Chesapeake Bay area,

    …most of [Norfolk, VA] lies over a relatively stable territory: only few critical areas…are affected by subsidence up to -4 mm/yr.

    Interestingly, in Miami Beach,

    One of the most affected areas is located in the middle section of the city built over reclaimed swamps. In this area…[t]he sinking of these buildings is mainly related to the compaction of the underneath sediments used to fill the swampy areas as consequence of the overload produced by the structures themselves.

  4. thanks for the heads up on this – clearly the “sea is not rising, it is the land that is sinking” will trickle down to the “everyman idiot” in a few months time, so always good to have a handy rebuttal – based on science

  5. The thing is, no matter how many times, or how clearly, denier bullshit is debunked, the same old bullshit keeps coming up. It’s like the moon landing hoax bullshit. And deniers only have to keep putting the same discredited points to apparently generate doubt in the minds of enough of the public to stop huge demonstrations against government policies that make matters worse. Instead, we get public compliance with the status quo, irrespective of what polls might say about public concern. There probably is no more serious issue than climate change but you’d never believe it from our actions.

    • @ Mike R – I know but my point is often that when I engage deniers I am not really responding to them but rather the “digital bystander”. I remember when I first got interested in Climate Science, as a very soft agnostic/sceptic, it really made a difference to – the ready easy knowledgeable rebuttal