Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.


Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup


All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe

Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...

New? Register here
Forgot your password?

Latest Posts


Earth’s oceans are routinely breaking heat records

Posted on 4 February 2019 by dana1981

Two recently published peer-reviewed studies make clear that the planet’s oceans are continuing to set hottest-yet temperature records nearly every year and, secondly, that the rate of ocean warming is in virtual lockstep with what modern climate models have projected.

Taken together, the findings, from studies led by Lijing Cheng of the Chinese Academy of Sciences Institute for Atmospheric Physics, demonstrate that climate scientists have developed an increasingly clear picture of the rapid warming of Earth’s oceans and its consequences.

One study, led by Cheng and colleagues and published in Advances in Atmospheric Sciences, concludes that 2018 was the hottest year ever recorded in the oceans. In fact, since the turn of the century, all but three years – 2007, 2010, and 2016 – have set a new ocean heat record.

Those three exceptions shared a key trait: Each was characterized by significant El Niño events, which transfer heat from the ocean to the air. As a result, for heat at Earth’s surface (in the air above both the land and oceans), 2007 was the second-hottest year up to that time, and 2010 and 2016 both subsequently broke the surface temperature record. 2018 was the fourth-hottest on record at the surface as a result of a La Niña event that year that kept more heat in the oceans than was the case in 2015 through 2017.

About 93 percent of global warming goes into heating the oceans, compared to about 2 percent warming the atmosphere. As the hottest year in the oceans, 2018 therefore was the hottest year ever recorded for the planet as a whole. And the amount of heat currently building up on Earth is equivalent to the amount of energy released by more than five atomic bomb detonations per second, every second.

What’s it all mean? Because humans live on Earth’s surface, it’s only natural that we focus primarily on the air temperatures that we experience most directly. But most of the heat trapped by the tens of billions of tons of greenhouse gases released into the atmosphere each year is absorbed by the oceans; it’s there that El Niño and La Niña events exert significant influence over the amount of heat transferred each year to the air. As a result, surface temperatures are quite variable, and the public at large can mistakenly focus on short-term surface warming changesand lose sight of the big picture: The heat has to go somewhere, and Earth overall is regularly breaking temperature records in the oceans, in the air, or in both … and doing so almost every year.

Argo floats lead to far more precise ocean heat content data

In the second paper, published in Science, a team of researchers led by Cheng compared the most recent measurements of ocean warming to model projections. In the most recent IPCC report, published five years ago, while ocean heat estimates fell within the range of model projections, the observational data between 1971 and 2010 was warming about 25 to 40 percent more slowly than the model average. However, ocean heat content data have become more accurate since the publication of that IPCC report. Scientists now have more data from Argo floats, thousands of which have been deployed around the world’s oceans in the years since 2003.

Prior to the deployment of those Argo floats, ocean heat measurements were made less frequently, primarily using “expendable bathythermographs” (XBTs) – a temperature probe connected by wire to a ship. The probe sinks down into the ocean, transmitting data until the wire runs out and the probe falls to the ocean floor. Because of challenges and dangers associated with monitoring and retrieving bathythermographs from ships during bad weather, scientists have invented expendable versions. One key challenge is that XBTs don’t measure the depth at which they’re recording temperatures, meaning that using XBTs to estimate ocean temperatures requires making assumptions about their rate of movement. As the study authors note, “Differing corrections to XBT measurements, as well as different approaches to infilling regions where data is sparse, have led to large differences in [ocean heat content] estimates prior to the Argo era.”

Rate of ocean warming in sync with climate model projections

In the study’s key finding, the authors concluded that the latest ocean heat content estimates by their team and two others – using the latest corrections to XBT measurements, better statistical methods to fill in the gaps between XBT measurements, and up-to-date Argo data – now find that the rate of ocean heating is right in line with the average projections from climate models. The study authors also incorporated a clever recent study published in Nature, led by Laure Resplandy of Princeton University, that estimated ocean heat content changes based on the amount of oxygen and carbon dioxide being released by the oceans. That research yielded similar results

[NOTE: The Resplandy study has been retracted due to an underestimate of its uncertainties].

Ocean heat content graph

Ocean heat content best estimate data from Domingues et al. 2008 for 0–700 meters combined with Levitus et al. 2012 for 700–2000 meters (green); Ishii et al. 2017 (yellow); Cheng et al. 2019 (blue); Resplandy et al. 2018 (purple); and the Coupled Model Intercomparison Project Phase 5 (CMIP5) model average (black). Data provided by Lijing Cheng, chart created by Dana Nuccitelli.

Drawing lessons from the research

There are a number of important points to take away from this research.

Click here to read the rest

0 0

Printable Version  |  Link to this page


Comments 1 to 14:

  1. Well I'm sure that warming oceans won't effect the methane clathrates as they are frozen so we don't have to worry.

    0 0
  2. Ocean anoxia is becoming a problem:

    If quantity of heat is increasing per unit volume, would that  lead to more intense el ninos?

    0 0
  3. Anybody who isn't worrying by now needs a medical checkup. Inability to face reality is a symptom of severe psychological impairment and may require medical assistance.

    0 0
  4. The question is, why is all of this happening? What causes it? 

    0 0
  5. Experts have calculated that if the entire ice cover melts, the sea level will rise by at least 60-70 meters, which will be equal to a global disaster. Melting glaciers also stimulate volcanic activity. Is it really something we are going to face any time soon? What is heats the Earth and Oceans so quickly?

    0 0
    Moderator Response:

    [DB] "What is heats the Earth and Oceans so quickly?"

    In a nutshell:  human activities.  A good summary post is here.

  6. Kate,

    Current high estimates for sea level rise are 4 meters by 2100 and 5-7 meters per century after that.  It will take a very long time to reach 65 meters of sea level rise.

    For Miami, Shanghai, the Mekong delta, Alexandria and other low places a rise of 1 meter would render the city uninhabitable so thinking of the absolute worst case is not necessary.  Current expert opinion is 1 meter by 2100 is likely.

    0 0
  7. What concerns me is the implications for carbon sinks.

    The land surface is warming at twice the rate of oceans warming and this is already having an effect through drought and fire which is destroying significant areas of forest.

    What will be the effects of ocean warming on the ability of oceans to (a) absorb (b) retain carbon?

    0 0
  8. Are you sceptical about 95% confidence interval ?

    How much degrees celsius all this terajoules are ?

    0 0
    Moderator Response:

    [PS] Error estimates for OHC have been studied in detail. See here for methodology and detailed results.

  9. So it is 0.15°C-0.2°C from 1955. I better understand why Terajoules are used !

    0 0
  10. I am not sure exactly what point you are trying to make here but if you are implying that OHC isnt a problem and scientists are trying to scare us with large numbers into their nefarious schemes for ..  I dunno... then consider:

    1/ Temperature change is not vertically uniform. The surface temperature change especially in top 100m is much larger and that is important for biosphere.

    2/ The major value in measuring OHC is that is a diagnostic of earth energy imbalance. As such it makes sense to measure it in energy units. Dont take my word for it, see what Roger Piekle has to say.

    0 0
  11. I just think that they could translate into degres for the 99% but that will have deserve their views. People will instantly compare to the global temperature and if you say them that 90% of the heat are in the oceans, you are done ! 

    Is it possible to explode mega bomb in the oceans to mixing all that fucking heat with the deep cold water ? USA and Russia together to explode all their bombs in the oceans ! What a dreams !

    The is some cool graph here : .When I see uncertaintees reduce over time like that, I say to myself that the science is on the right track...

    It should be 0.35-0.4 ℃ for the first 300 meters.


    0 0
  12. As this is your first post, Skeptical Science respectfully reminds you to please follow our comments policy. Thank You!

    I signed up for this site because of some fascinating scientific dialogue from 2010. Wow, has the tenor changed.

    My understanding of the functioning of the oceans/atmosphere interaction is  that 99% of the carbon dioxide of the surface of the earth is dissolved in the oceans. Therefore one must assume that the oceans act as a buffer in large measure for the amount of carbon dioxide in the atmosphere. Am I mistaken, or is it not true that as the temperature  of a liquid increases its capacity for dissolved gases increases up to a point of the liquid becoming a gas itself, boiling.  As such, I think it is reasonable to expect a very small rise in the temperature of the ocean to cause a rather massive affect on a relatively small amount of carbon dioxide in the atmosphere. Has this been studied? Does anyone have any references to address this functioning of the ocean as a CO2 buffer?

    0 0
    Moderator Response:

    [TD] The amount of CO2 able to be held by the oceans is a function of not only the temperature of the ocean, but the amount of CO2 in the atmosphere. For details, in the left margin below the thermometer, click the "OA not OK" button.

  13. Dr. C,

    Your question is difficult to understand.  You seem to suggest that as the ocean warms, more CO2 will dissolve in it.

    This notion is mistaken.  As the temperature of a liquid increases the solubility of a gas in the liquid decreases.  Specifically, as the temperature of the ocean increases the solubility of gasses in the ocean decreases.

    That means that as the ocean temperature increases it will outgas CO2 and lead to more CO2 in the atmosphere.  Human emissions are so large that this effect is negligible so far.

    An additional problem is that increasing ocean temperatures means less oxygen dissolved in the ocean which kills fish and other organisms.  This effect is significant and parts of the ocean, especially the tropics and the deep ocean, are becoming more depleted in oxygen.

    I have very strong recollections of boiling water in General Chemistry lab to remove the CO2 for use in titrations.  Hot water does not hold gasses.

    The moderator refers to the fact that as the gas pressure increases more gas dissolves in the ocean.  This effect causes much more CO2 to dissolve in the ocean, about 25% of released CO2, and causes increased ocean acidification.  If you do not mind ocean acidification killing all the fish than this effect does reduce air concentrations of CO2.  If humans stopped emitting CO2 today the atmospheric concentration of CO2 would decrease as the deep ocean absorbed more CO2 due to the concentrations effect.

    Does that answser  your question?

    0 0
  14. Not really. I did a lot of background reading over the last two days, and this issue is far from settled. The CO2 dissolved both as gas and bicarbonate do act as a buffer to atmospheric CO2, but also the deeper ocean layers contain higher concentrations and occasionally fume CO2, especially when the surface winds are in play. Furthermore, there is very little data from the Southern Hemisphere oceans during the colder weather, because of he harshness of the conditions for those vessels that collect and analyze ocean gas samples for the last 3 decades. The dynamic is much more complicated and the simplifications are just inadequate to the data.

    0 0

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

The Consensus Project Website


(free to republish)

© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us