On the relative change between the level of ocean and land in the Sacramento Delta

When I posted a couple of weeks back on the fact that land in the Sacramento-San Joaquin Delta is subsiding faster than sea level is rising, a smart reader asked privately, “Yeah, so what’s the point?”

My reader’s observation was, in essence, that it doesn’t really matter much in terms of policy response whether the ocean is rising or the land is sinking. And that was precisely the obscure point about which I was thinking, but about which I wrote poorly.

Consider what happened in North Carolina when a panel of scientists prepared a report for the state looking at the best available science on sea level rise:

The final recommendation was for the state to plan for 39 inches of sea level rise. This number corresponds well with expert reports produced in other states.

And the response?

NC-20, a group purporting to represent North Carolina’s coastal counties, attacked both the integrity of the science panel members and the body of sea level rise literature that was reviewed. The rebuttal consisted largely of oft-repeated arguments pulled from the climate skeptic blogosphere, along with an adamant assertion that predicting the future is impossible. To the great surprise of those of us on the state’s science panel, these tactics have worked.

To the extent that a change in the relative elevation of sea and land in California’s Delta poses a threat that requires a policy response (more robust levees, perhaps?), it doesn’t really matter whether the sea is rising or the land is falling. But to the extent that rising sea level is a driver, California runs the risk of a North Carolina problem, in which the policy discussion becomes mired in the identity politics of climate change.

Thank heavens we now know the land is sinking and we don’t have to fight that fight!


  1. Sorry, not enough denialists in this neck of the woods to manage any such thing, so no risk.

  2. Also, I don’t know but suspect the pattern of inundation wold be quite different depending on the degree of influence of the two factors, because SLR is even and subsidence isn’t.

  3. “Thank heavens we now know the land is sinking and we don’t have to fight that fight!”

    Exactly. The N Carolinians know that land subsidence requires real world solutions like stout seawalls, higher bridges, new roads and levees. However if it were due to anthropogenic seal level rise, none of those solutions are relevant. The way to fight ACC sea level rise is with wind turbines, solar panels, electric car subsidies, carbon rationing programs, cap&trade and all manner of costly waste. In other words they want their money spent on real and effective solutions, not wasted on conspicuous environmental smoke and mirrors. Can’t blame them for that.

    It matters alot if the land is sinking rather than the ocean is rising. It matters alot.

    So you’re right, thank heavens you don’t have to fight that fight.

  4. Screw science – just give me a decent surveyor.

    Am I right or am I right, bro?

    Your thoughts on this issue have gone from not entirely clear to deliciously ambiguous. Congratulations, John. You will now attract the full spectrum of respondents, as klem’s comments portend.


  5. Klem – Thanks for the comment, but I think you’ve bollixed up the logic. Given that we seem to have decided as a planetary community not to go the wind turbine/solar panel route, the policy responses needed in North Carolina are the same as you suggest (stout seawalls, etc.). Even if the planetary community *does* take decarbonization seriously, sea level rise that’s already in the pipeline will require those same steps. What North Carolina has essentially done is attempted to legislate a blindness to the need to take the necessary adaptation steps.

    Luckily for my beloved state of California, either because Steve is right re the politics there, or because of simple subsidence, the politics are different. Not that I have any confidence that California will really do anything anyway, whatever the driver of rising waters and sinking land.

  6. The problem (as a couple of these comments show) with reflexive Kloorism is that while problems may appear similar on the surface, allowing agreement on how to proceed against those who deny one of the causes, there are differences and you can be lead to the wrong choice because there really are differences.

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