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Sea temperatures are at a massive record high

The ocean is basically a giant heat engine, absorbing heat from the atmosphere and recycling it via rising and sinking waters. It can absorb a vast amount of heat, but it has its limits, and eventually the surface water absorbs so much heat that it can't absorb more without itself heating up. We reached this point years ago, and this year the temperature increase in the world's oceans is more dramatic than ever:

At the beginning of June, sea temperatures were about 0.3°C higher than ever in recent history and about 0.7°C higher than the 1982-2011 average. As a result, the extent of global sea ice is at a record low:

A new report estimates that we will likely see an entirely ice-free Arctic summer within one or two decades. This will happen regardless of future emission scenarios.

There are limits to what even the sea can do to keep global temperatures stable. We outran those limits years ago and now both land and sea temperatures are rising inexorably. On land this means droughts, wildfires, crop failures, and extreme weather. On the sea it means coral destruction, the loss of Arctic ice, flooding in low-lying areas, and increased destruction from hurricanes and typhoons.

The sea may be a heat engine, but it's a sluggish heat engine. It heats up slowly, and likewise it would cool down slowly even if we stopped dumping carbon into the atmosphere tomorrow. This is one reason that climate change is such an urgent problem. Sure, land temperatures are up only about 1°C so far, but much of that is because the world's oceans have been absorbing so much excess heat. That bulwark ended years ago and the seas have long since reached their heat absorbing limit. What's more, even if we reached net zero carbon emissions immediately the sea has a tremendous amount of momentum already baked in the cake and it will take decades for sea temperatures to stop rising and finally begin to moderate. This is why we have so little time to lose.

28 thoughts on “Sea temperatures are at a massive record high

  1. Five Parrots in a Shoe

    Any sentence that includes the words "stop global warming" is a nonsense sentence. Global warming is a done deal, and we need to start seriously planning for the consequences. It won't be long before major coastal cities start flooding so frequently that living there will no longer be viable: Kuala Lumpur and Miami are two obvious examples; and wildfires in the western US, Southern Europe, and Australia will only get more intense in the foreseeable future.

    Yet the only people I see really planning for this reality are those insurance companies who have stopped providing homeowner's coverage in FL and CA because of floods and fires. What is the world going to do with all the millions of refugees from Bangladesh and Indonesia when they lose their homes? Politicians in the free world need to be discussing this as a top priority.

    1. ruralhobo

      It's not a nonsense sentence, it's what we must do. Even if it takes a while for a car to stop after hitting the brakes.

    2. aldoushickman

      "Global warming is a done deal, and we need to start seriously planning for the consequences"

      Jeebus, it's not a switch with two positions. It can get much, much worse, so it's vital to talk about stopping it and getting to carbon net-zero.

      Fully agree that consequence planning is necessary.

      1. Five Parrots in a Shoe

        Yah, I could have written, "Given the realities of the politics and economic pressure that motivate fossil fuel consumption, the best case scenario is that global warming will top out at a higher level than even the pessimistic outlook from the IPCC", but that just doesn't make very good, punchy writing.

    3. Brian Smith

      You claim that insurance companies have stopped providing homeowner's coverage in Florida because of floods and fires. Do you have any source for this claim?

      One source claims that two insurers stopped providing insurance because one was placed in receivership and the other was forced into liquidation. Others have withdrawn or scaled back operations due to a 2017 Florida supreme court decision that made litigation much riskier and more expensive. https://www.insurance.com/home-and-renters-insurance/home-insurers-leaving-florida

      This source recognizes that there have been bad years for storms (such as 2004 and 2005) but also cites the legal changes that increase insurers' exposure. https://www.forbes.com/advisor/homeowners-insurance/why-is-homeowners-insurance-in-florida-such-a-disaster/

      This source claims that fraud and litigation risks are the main issues. https://www.bankrate.com/insurance/homeowners-insurance/florida-homeowners-insurance-crisis/#curb

      It's worth noting that the companies that have withdrawn in the last few years are smaller companies; the larger ones are still operating there. If a realistic expectation of catastrophe from climate change were the driving motivation, I'd think the larger companies would have more access to the best information.

  2. golack

    We certainly need an "all of the above" strategy. Though the best thing to do is still to stop burning fossil fuels.

    Note: with rising ocean temps, whacky things can happen. Ocean currents may be disrupted--and that's very scary.

    1. tango

      And not just cutting back on carbon emissions --- we should also be working on carbon sequestration, mitigation techniques, and even entertaining geoengineering ideas like painting our roofs white to wackier stuff like sending up more clouds to reflect incoming sunlight back into space.

  3. Brian Smith

    "This is one reason that climate change is such an urgent problem. ... This is why we have so little time to lose."

    This displays magical thinking. It assumes that there is a solution that might be implemented. Even if the US, Canada, Europe, and Japan all get to Net Zero, this will solve less than half the problem, because most emissions are coming from China, India, and other developing countries. And these other countries aren't even pretending to try for Net Zero. And the US, Canada, Europe, and Japan are only pretending.

    Like it or not, the primary effort should be on mitigation and adaptation, not on prevention.

    1. aldoushickman

      "Like it or not, the primary effort should be on mitigation and adaptation, not on prevention."

      That would make a lot of sense if societies were like people and could only focus on a couple of things at a time. Well, even then, it wouldn't make sense--every dollar spent on prevention is worth multiple dollars in mitigation. We can't avoid mitigation at this point, but that's not a reason to backseat prevention.

      "Even if the US, Canada, Europe, and Japan all get to Net Zero, this will solve less than half the problem, because most emissions are coming from China, India, and other developing countries."

      This is a foolish argument. "We can only solve half the problem! So we should solve _none_ of the problem!"

      1. Brian Smith

        "every dollar spent on prevention is worth multiple dollars in mitigation"

        What is your logic here? If a dollar spent on prevention won't prevent, how much mitigation would it eliminate? How would you calculate this?

        "We can only solve half the problem!"

        I didn't claim we could solve half the problem. I claimed that we (our elected leaders) are only pretending to attempt to solve half the problem. But all this pretense isn't even based on a remotely viable pathway. So, the money being spent in the name of prevention is largely wasted, and takes away resources that would be better spent on preparation for mitigation.

        1. aldoushickman

          "What is your logic here? If a dollar spent on prevention won't prevent, how much mitigation would it eliminate"

          The logic is pretty plain: compare costs of industrial removal of CO2 from the atmosphere with the costs of not putting it there in the first place. For most use cases, the cost of avoiding CO2 emissions is mildly negative, whereas we do not have a viable technology to remove CO2 (although the IRA includes ~$180/ton tax credits). Given that CO2 in the atmosphere will cause warming on thousand-year timescales, mitigation measures would have to be maintained over vast epochs of time--say, enough time for the Roman Empire to arise and collapse into dust a few times over. Take the sum of the area under that curve, and even trivial costs become collossal. And all of that is based on a very conservative estimate of both the impacts from each additional ton of CO2 and the mitigation measures required thereby to scale linearly, which they plainly don't.

          So yeah, we need to spend some resources on mitigation, but inadequate seawalls is not a civilization killer: letting warming continue a few degrees more (say, until we can't grow cereal crops) absolutely is.

          "the money being spent in the name of prevention is largely wasted"

          What's *your* logic here? The money being spent in the name of prevention is spent on things like acquiring wind and solar energy, and investments in batteries. All of these things are net benefits even *before* you consider climate (renewables are cheaper on a levelized kwh basis than fossil; reducing emissions of PM from fossil confers enormous public health benefits in terms of fewer deaths, hospitalizatons, missed days of work/school, etc.), so it certainly isn't "wasted" just because you'd rather it *all* went to like building seawalls and cooling centers or something.

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  5. Adam Strange

    There is a chance that the human practice of pumping loads of carbon dioxide into the air will make many parts of the world uninhabitable for mammals (see "wet bulb temperature"), but will prolong by a few thousand years the 11-14,000 year warmer interglacial period between global ice ages that we are presently experiencing.

    During the last ice age, the earth was able to support only about 2-3 million humans. I'm not anxious to return to that state.

    Chart 12, red line shows air temperature of the earth near Vostok for the past 450,000 years before present. Note that it's pretty nice right now, but the cycles predict that it is likely to get chilly again soon.
    https://globalchange.umich.edu/globalchange1/current/labs/Lab10_Vostok/Vostok.htm

    A warmer planet might be good for many reasons, but we don't want to overdo it. Venus is not a destination.

    1. Coby Beck

      The elevated CO2 levels will persist for 10000 years. We are headed to an ice free state, forget another glacial period. This ice age is over.

    2. Andrew

      We were headed for a new ice age in a few thousand years after the last temperature maximum but that was while CO2 levels fluctuated between 180 ppm and 280 ppm over the last 800,000 years. With the additional CO2, we are now at a level not seen in a few million years. While it's possible the climate might shift to a new regime that allows an ice age, e.g. the Atlantic Meridional Overturning Circulation (AMOC) stopping, it's probably not a such a good idea to run that experiment on the planet. Assuming no big shifts, we're probably looking at least a couple of hundred thousand years minimum until the next ice age.

  6. Dana Decker

    There are some who say we should adopt nuclear (and even low carbon natural gas) as a "bridge" to the day when we can be 100% solar/renewals. I think that's a good idea.

    But nobody, NOBODY of prominence is saying we should strive for ZPG (zero population growth) right now and stay with it until the bridge is completed. ZPG would reduce estimated CO2 by 30% by the end of the century.

    Anyone complaining about global warming who does not forcefully advocate ZPG is not a serious person.

    1. Brian Smith

      People have advocated ZPG in the past. China tried to implement it with the One Child Policy. India, at the urging of western governments and institutions, tried it with forced sterilization. These are not good models.

    2. aldoushickman

      "Anyone complaining about global warming who does not forcefully advocate ZPG is not a serious person."

      This is nonsense. All forecasts of global population growth show relatively near-term leveling off of overall population followed by population decline, because richer societies have fewer offspring. You don't have to advocate for ZPG as a policy, because people do that as a matter of preference anyway.

  7. D_Ohrk_E1

    For constant, various graphical climate change updates, you should follow Zack Lebe on birdsite or Mastodon.

    I track (S)ea (S)urface (T)emperature anomalies, mostly to keep an eye on the (E)l (N)ino (S)outhern (O)scillation, which, it appears to be headed for a record El Nino. Using SST anomalies, you can visually see the difference between 1985 and 2023.

    We have already failed at addressing climate change. 1.5°C is an arbitrary number that we will have exceeded before the end of this decade -- much sooner than had been expected in the past. Aside from the US and a handful of nations, emissions are climbing faster now than 5 years ago. It is impossible to avoid mitigation, and it will cost a few trillion dollars in the US alone. Are we going to argue about the scale of debt and do nothing? Is NYC going to abandon its subway system, therefore?

    ¯\(°_o)/¯

    What do? Nuthin. Absolootelie nuthin.

    1. Brian Smith

      I agree that mitigation is the obvious course. What will the trillions do? Where did this estimate come from?

      Thanks.

      1. D_Ohrk_E1

        Take this partial response to the threat to NYC as a baseline. It's $120B without being fully engineered and is expected to be inadequate within a decade of completion.

        Meanwhile Miami isn't directly addressing sea level rise so much as it is addressing a future 5% storm event, and it does not address all of Miami, and it'll still cost over $4B. Rather, what they -- and lots of others -- are relying on, is some future technology that makes mitigation cheaper.

        Maryland alone thinks it'll need $27.4B to mitigate against rising sea levels.

        It is well-known and accepted, that if you block rising water in one area, all of the adjacent areas will then flood. It's baked into FEMA mitigation rules and flood zone estimates. The piecemeal mitigation highlighted above will end up requiring adjacent coastal areas to address even higher flooding.

        Furthermore, the frequency of coastal beach municipalities having to replace sand will speed up, even as they plan to build structures to slow down sand erosion.

        And this doesn't even touch inland issues of climate change mitigation!

        1. Brian Smith

          The mitigation measures you've linked don't seem to be related to climate change or warming, and mostly not to sea level rise. I can't confirm or deny the feasibility or effectiveness of any of them, but they sound somewhere between plausible and urgent, even if there is no future climate change. It seems like these would be a better use of scarce resources then futile efforts to reduce emissions with electric cars and windmills.

        2. Coby Beck

          "... if you block rising water in one area, all of the adjacent areas will then flood. [...] The piecemeal mitigation highlighted above will end up requiring adjacent coastal areas to address even higher flooding."

          While technically correct, in the case of sea level rise "adjacent" areas mean all the coastal areas in the entire world and the additional flood water would be spread over the area of the entire ocean. I don't think there is a practical concern here.

  8. Citizen99

    The heat capacity of water on a mass basis is about 6 times more than air. And the density of water is 800 times more than air at atmospheric pressure. Therefore a volume of water can store 4800 times more heat than the same volume of air.

    This is why the ocean can soak up so much of the trapped heat from global warming. And why it's so alarming to see the ocean heat up this much. The surface warms the fastest, and over time much of that heat gets mixed down into the colder depths. But it's the surface temperature that really influences how destructive hurricanes are, how much moisture they contain, and how fast they intensify. This is where global warming is really going to beat the crap out of us.

    And YET -- we still have to fight climate denial, which is still potent in our politics. God damn them.

  9. ConradsGhost

    The funny thing about almost every dystopian vision is the inability to grasp how mundane the end of *everything* really is. A perfect analogy is the granular scholarship documenting the rise of National Socialism, where as seen from the day to day perspective of the ordinary citizen the change from struggling democracy to catastrophic fascism was in many ways unremarkable, in particular unremarkable to a people whose lives and identities were deeply entwined with and formed by the personal, social, and economic structures that both made and unmade them.

    This is exactly what’s happening with the human destruction of a livable biosphere. Global warming is just the most obvious and proximate dimension of how humans are destroying almost every non-human system on the planet. It’s the overwhelming catalyst that would change everything on its own; the kicker is that it’s just one facet of humanity’s endemic destruction of life on Earth as we know it. This is not random doomsaying, or prepper horseshit, or christianist garbage. It’s data, data that’s available to anyone who chooses to see it, and to argue against any particular one of the data points in ignorance of the whole is willful delusion, special pleading, intentional or non-conscious delusion.

    The collapses and concomitant destruction have started and are going to occur with increasing speed and magnitude, not in some distant future but in our lifetimes. A comprehensive evaluation of the aggregate publicly available evidence makes this crystal clear. We are headed for a huge, huge shift in everything we see as ‘normal’, and not in a good way. Humans as a species, mot as a very small subset of privileged first worlders, will not change from their current path unless forced to do so. We won’t, and to think otherwise is to ignore what’s right in front of our faces.

    It’s over. The goose is cooked. S*** is going o get really, really bad, and fast, faster than anyone wants to acknowledge. That’s the reality. It has nothing to do with “but what can we do?” It has nothing to do with “hope.” It has nothing to do with any of our desperate attempts to minimize, distract, ignore, or whatever. It just is. The best thing any thoughtful human can do is to shut up, accept this, and let it sink in, let it really sink in. Because if we don’t do this then we are stumbling in the darkness, and given what we’re facing this means we truly are f****d.

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