Atmospheric Sciences Opinion

Taking the Pulse of the Planet




Ocean heat content and atmospheric carbon dioxide concentration measurements.



Why Do Changes in Surface Temperatures Obscure Signals from Global Warming?





What Global Warming Signals Can Be Found in the Oceans?







Human-Caused Warming or Just Natural Variations?










OHC and SLR Are Robust Indicators of Global Warming




The Need to Take the Pulse of the Planet




















Author Information


  • Mari Mes

    Prof. Walter H. Munk came to similar conclusions years ago of globally increasing seawater temperatures. He based that on a history of deep sea speed of sound measurements he organized. I believe he also was one of the first (if not the first) to recognize that a large part of the sea level rise can be attributed to a global increase in seawater temperature.

  • Hagen Marilia

    Actually it would be part of my question . However, the temperature changing in the atmosphere would increase pressure on the oceans.
    The oceans receded in Southern Atlantic for almost a month August – September and the Hurricane Harvey and Irma , Katia, Jose were created exactly during the period. Somehow, the rising of temperature on the atmosphere must be involved

  • zaharia

    [Please note: the text below cancel and replace my comment of Sept 15.]

    The entire ocean surface is ~360 million sq. kilometers. The upper 200 m thick layer has a volume of ~72 million cubic kilometers. (or 72.10**18 kg.)
    Assuming a 1°C temp. increase since 1960, the heat content of this layer has increased of ~300 ZJ.
    This is a share of more than 85% of the total OHC increase, as computed elsewhere.

    The cumulative ~55 years rough figures that may be related to this amount of “anthropogenic extraheat”… are the following:
    ~1400 GtCO2 (or carbon dioxyde emissions of ~25 GtC02 /y, on average),
    ~4100 PWh or ~15 ZJ of primary energy consumption (over ~half a century, or ~6,2 Gtoe / y, on average), and
    ~ 2750 T$ (2012 value) of world PIB. (Or ~50 000 G$2012 / y, on average.)

    The above figures show that humankind is using the climate system as an amplifier: for each ZJ of primary energy consumption(*), there is an OHC increase of more than 20 ZJ.
    This average figure, (computed over half a century), is certainly below the present value, related to an over 400 ppm CO2 concentration, (rather than the ~345 ppm 1985 average value.)

    (*) 1 ZJ is about ~23,9 Gtoe. (At present rate, 1 ZJ of primary energy is consumed every ~29 months.)

  • drseismo

    This entire discourse is Much Ado About Nothing. Attempting to predict the earth’s temperature by modeling a myriad of complex interactions and processes is ludicrous. The authors’ proposal to add ocean heat content and Earth’s energy imbalance to the equation is the final straw of an already unmanageable problem.

    I suggest a better approach is to assume the earth’s climate system is a black box and to simply focus on analyzing the output, the earth’s temperature. If one cannot analyze the output of a complex system, what is the likelihood that the complex system itself can be modeled? Modeling may be a lot more fun and lead to a lifelong career in climate science, but the amount of progress will probably be like the distance one can travel on a stationary bicycle.

    A simple numerical analysis of the HadCRUT4 time-temperature data indicates a high likelihood of the beginning of an absolute decline in the global mean surface temperature trend line within the next decade. The first derivative of the temperature trend line is positive but has decreased in value every month for the past 20 years. The derivative is likely to become negative in the mid-2020s and increase in negative value well into the 2030s, i.e., the mean global surface temperature will decline.

  • zaharia

    The upper ocean 200 m thick layer has a volume of ~72 million cubic kilometers, (or 72 E18 kg? The entire ocean surface is rather ~360 million sq. kilometers.)
    Accordingly, the HC of this layer has increased of ~300 ZJ, (assuming a 1°C temp increase, since 1960).
    This is a share of more than 85% of the total OHC increase, as computed above. The cumulative ~50 years rough figures that may be related to this amount of “anthropogenic extraheat”… are the following:
    ~1500 GtCO2,
    ~3250 T$ (2012 value) of world PIB (that is ~65 000 G$2012 / y, on average) and,
    ~5000 PWh or 18 ZJ over half a century (that is ~8,5 Gtoe of primary energy consumption / y, on average.)

    It seems to me that humankind is using the climate system as… an amplifier (!)
    The above figures do show that… for each ZJ of primary energy consumption, (about ~23,9 Gtoe used every 29 months), there is an OHC increase of almost 20 ZJ…
    This average figure, (computed over half a century), is certainly below the present value, related to an over 400 ppm CO2 concentration, (rather than the 345 ppm 1985 average value.)

  • Paul Matthews

    For the benefit of the scientific illiterates who don’t seem to be able to do the calculation, here’s how it goes.

    The change shown in the ocean heat graph is about 35 x 10^22 J over 60 years, about 6 x 10^21 J/yr.
    The mass of the oceans is about 1.4 x 10^21 kg, and the specific heat capacity of water is about 4200 J/kg/C.
    So the average temperature rise of the ocean is 6/1.4/4200 which is about 0.001 degrees C per year.

    • serfbaja

      Thanks….I needed that. The article (with only the calculations…no translation) would leave some to believe the temp rise in the ocean was 0.33 degree from 2015 to 2016

  • Paul Matthews

    “How fast is Earth warming?”

    That question unfortunately isn’t answered in this article. But it is a fairly easy calculation to do if you look up the mass of the oceans. It turns out to be slightly less than 0.001 degrees per year.

    I wonder why this truly terrifying number isn’t included in the article?

    • jhvtex

      Probably because it’s bogus, and you are little more than a denialist troll.

    • James Owens

      Put all the numbers together – and take the actual number in the article – Table 1, GMST (global means surface temperature) – then you get about 0.016 degrees C in surface temp per year. That’s 0.16 degrees per decade. But forget the linear trend, the overall heat accumulation, which is best checked with ice melt and ocean heat content, been speeding up.

    • Lijing Cheng

      What matters for humanity is not whether the very deep ocean is warming but whether the upper ocean where we and our food supply live are changing significantly. The rate of warming is equivalent to the upper 200 m of the ocean warming by 0.2C per decade since 1960. Given that this applies to the entire ocean which is about 3.6 million sq kilometers, it is a huge amount of energy. We provide a comparison in our article “the increase in OHC observed since 1992 in the upper 2,000 meters is about 2,000 times the total net generation of electricity by U.S. utility companies in the past decade.” This energy contributes to the observed rise of sea level, and the depth of the ocean does not matter. For Texas and Florida, it still results in flooding!

      • Texas and Florida are flooding due to land subsidence from ground water extraction. To blame CO2 warming misrepresents the real issues.

        Furthermore Cheng’s earlier paper reports “The sea surface (1–100 m) temperature has decreased in this century, accompanied by warming in the 101–300 m layer. ”

        “In addition, we show for the first time that the ocean subsurface within 301–700 m experienced a net cooling, indicative of another instance of variability in the natural ocean.”

        Cheng also adds, “the ocean layer of 701–1500 m has experienced significant warming”, While oceanographers from MIT show that the oceans from 2000 meters and below have been cooling.

        Depending on how one weights the depth layers, there may be no significant ocean warming.

        Furthermore because of the limited sampling and the fact that currents are constantly shifting water masses and heat, if regions with stored heat extremes such as the north Atlantic export heat to a cooler region, that redistribution of heat can be mistakenly interpreted as global warming.

        • zaharia

          This comment reveals a lack of knowledge, in particular, the vital fact that the thermal capacity of the world oceans is ~1000+ times greater than that of the atmosphere.
          A circonstance leading to 90+% of the excess heat going in the ocean part of the climate system… This increase of the OHC is not really a blessing, but it is a good proxy of what is going on.