From the 1950s, and especially from 1975, the global surface ocean has shown a significant and steady warming trend. However, since 2004, that warming seemed to stall. Researchers measuring the Earth’s total energy budget (the energy coming in from the Sun and the radiated heat) and they noticed that more heat was coming in then going out; but if the oceans weren’t warming, then where did the heat go?


A case of the missing heat

This was one of the main arguments of “climate change deniers”; the oceans aren’t warming, so everything’s ok, right? As usual, this kind of shallow thinking was wrong.

Magdalena Balmaseda and her team have conducted a series of ocean heat analysis, and their research was published in Geophysical Research Letters. They showed that while the shallow global waters, up to 700 meters had a constant temperature from 2004, the deep ocean was heating at an unprecedented rate.

This is not the first time it was suggested that the deep ocean was paying the price for anthropogenic global warming. In 2011, Kevin Trenberth from the National Center for Atmospheric Research presented more or less the same results, suggesting that extra energy entered the oceans, with deeper layers absorbing a disproportionate amount of heat due to changes in oceanic circulation (full article here).

Global warming is bad enough as it is – we see its effects more and more: drought, water shortage, change of seasons, sea level rise, and oh so many more. But why is the deep ocean so significant?

First of all, oceans are host to the largest biodiversity on our planet – by far. We may have mapped all but a sliver of Earth’s landmass, but the oceans are still mostly a mystery. Also, the difference in temperature between the deep ocean and the shallower dramatically affects the thermohaline circulation – the main driver of the global oceanic currents. Any change in the temperature will cause a change in the circulation, which can have dramatic, very hard to predict events.

Still, one thing’s for sure – this will not go without consequences.

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  1. 1

    Forgive my skepticism (you know, skepticism, that trait that differentiates science from religious dogma), but how is it that heat is now sinking, instead of rising, and not only that, but sinking from the atmosphere, through the top levels of the ocean, to the deep ocean, without warming the top levels in the process? And again, how is it that the laws of thermodynamics — heat rising — no longer apply? I eagerly await what shall undoubtedly be a ridiculous and completely unsubstantiated explanation full of DOOOM!

  2. 2

    And any warming that would be occurring would be from conditions hundreds of years ago. The ocean is a REALLY big pot of water that takes hundreds of years to heat.

  3. 3

    The deep oceans would still be cooler than shallower areas, but the temperature gradient with depth may have flattened out. (i.e. the deeper parts are heating up but are still cooler than shallow waters, thus global warming and physics principles are still oaky…).

  4. 4

    The climate models have failed to predict real world measurements so the scientists are trying to figure out why the world isn’t doing what the models say it should be doing. How about fixing the models with more realistic assumptions first.

    So far as heat sinking or not — heat moves from the warmest to the coldest, so yes, enormous amounts of heat is going into the depths of the ocean. However, unless something has happened to affect the heat balance, I strongly doubt that any more heat is going into the depths than there was 10 or 15 years ago. If something has happened to change that, what is it?

  5. 5

    If energy is going to the deep oceans instead of the atmosphere, we may be in for some very good news. The same amount of energy that would heat the surface are 1 degree would heat the deep oceans a tiny fraction of that.

    And heat travels (by conduction and convection) from the warmer to the cooler, so that transfer of energy out of the ocean would take an extremely long time.

    None of the computer models show this deep ocean heating, so we can not say we understand it, but if that is where the heat energy is going, it’s partly good news.

    For further discussion see:

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