UPDATED: See the update at the end of the post about climate sensitivity.
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Alternate title: Press Release Plus Mainstream Media & Blogosphere Responses to Resplandy et al. 2018
Before we get to the fun stuff, the paper being discussed in this post is Resplandy et al. 2018 Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition (paywalled). Its abstract reads (without footnotes):
The ocean is the main source of thermal inertia in the climate system. During recent decades, ocean heat uptake has been quantified by using hydrographic temperature measurements and data from the Argo float program, which expanded its coverage after 2007. However, these estimates all use the same imperfect ocean dataset and share additional uncertainties resulting from sparse coverage, especially before 2007.
Here we provide an independent estimate by using measurements of atmospheric oxygen (O2) and carbon dioxide (CO2)—levels of which increase as the ocean warms and releases gases—as a whole-ocean thermometer. We show that the ocean gained 1.33 ± 0.20 × 1022 joules of heat per year between 1991 and 2016, equivalent to a planetary energy imbalance of 0.83 ± 0.11 watts per square metre of Earth’s surface. We also find that the ocean-warming effect that led to the outgassing of O2 and CO2 can be isolated from the direct effects of anthropogenic emissions and CO2 sinks.
Our result—which relies on high-precision O2 measurements dating back to 1991—suggests that ocean warming is at the high end of previous estimates, with implications for policy-relevant measurements of the Earth response to climate change, such as climate sensitivity to greenhouse gases and the thermal component of sea-level rise.
Basically, Resplandy et al. 2018 et al. are basing their estimates of the heat uptake for the “whole ocean” since 1991 on atmospheric measurements of oxygen and carbon dioxide as proxies, not on ocean temperature observations. Does one assume that “whole ocean” means from coast to coast and from ocean floor to surface? I believe so.
As far as I can tell, based on the abstract, this is not an examination of, or an attempt at correcting, global sea surface temperature records, which make up the ocean portion of the global surface temperature record. Considering that the definition of “climate sensitivity to greenhouse gases” is broadly defined by the IPCC as (my boldface) “the equilibrium global mean surface temperature change following a doubling of atmospheric CO2 concentration”, we must assume that the authors are referring to another definition of “climate sensitivity to greenhouse gases” in their abstract, not the broadly accepted one.
NOW FOR SOME FUN STUFF
The press release for the paper can be found at Eurekalert: Earth’s oceans have absorbed 60 percent more heat than previously thought. The first few paragraphs read (my boldface):
For each year during the past quarter century, the world’s oceans have absorbed an amount of heat energy that is 150 times the energy humans produce as electricity annually, according to a study led by researchers at Princeton and the Scripps Institution of Oceanography at the University of California-San Diego. The strong ocean warming the researchers found suggests that Earth is more sensitive to fossil-fuel emissions than previously thought.
The researchers reported in the journal Nature Nov. 1 that the world’s oceans took up more than 13 zettajoules — which is a joule, the standard unit of energy, followed by 21 zeroes — of heat energy each year between 1991 and 2016. The study was funded by the National Oceanic and Atmospheric Administration and the Princeton Environmental Institute.
First author Laure Resplandy, an assistant professor of geosciences and the Princeton Environmental Institute, said that her and her co-authors’ estimate is more than 60 percent higher than the figure in the 2014 Fifth Assessment Report on climate change from the United Nations Intergovernmental Panel on Climate Change (IPCC).
“Imagine if the ocean was only 30 feet deep,” said Resplandy, who was a postdoctoral researcher at Scripps. “Our data show that it would have warmed by 6.5 degrees Celsius [11.7 degrees Fahrenheit] every decade since 1991. In comparison, the estimate of the last IPCC assessment report would correspond to a warming of only 4 degrees Celsius [7.2 degrees Fahrenheit] every decade.”
How silly can Laure Resplandy be? The oceans aren’t “only 30 feet deep”, and it’s a waste of time to imagine they’re “only 30 feet deep”. According to NOAA’s National Ocean Service webpage How deep is the ocean?, on average, the oceans are about 12,100 feet deep. So the heat uptake for the “whole ocean” is spread out to depths of 12,100 feet, not “only 30 feet”. I’ll let readers do the math for the assumed temperature change for the “whole ocean”. It’s nonsense like that that gives climate scientists/activists/fifteen-minutes-of-fame seekers their bad names, and make people with common sense question the results of their papers after reading the foolish quotes in the press releases. Why? you ask. It’s very obvious that Laure Resplandy was avoiding giving the actual temperature rise of the “whole ocean” since 1991, because it’s a miniscule change in temperature.
The press release continues with discussions of policy, also undermining their paper (my boldface):
Climate sensitivity is used to evaluate allowable emissions for mitigation strategies. Most climate scientists have agreed in the past decade that if global average temperatures exceed pre-industrial levels by 2? (3.6?), it is all but certain that society will face widespread and dangerous consequences of climate change.
The researchers’ findings suggest that if society is to prevent temperatures from rising above that mark, emissions of carbon dioxide, the chief greenhouse gas produced by human activities, must be reduced by 25 percent compared to what was previously estimated, Resplandy said.
The “2? (3.6?)” suggests Eurekalert needs proofreaders, so if you need a job…just saying. Here’s the archived link to the press release, just in case they correct the typos.
Also, as noted earlier, this paper, according to its abstract, did not attempt to estimate sea surface temperature changes; it only dealt with ocean heat uptake for the “whole ocean”. So it did not address any component of the IPCC’s broad definition of climate sensitivity, which again is (my bold and brackets) “the equilibrium global mean surface temperature change [not ocean heat uptake] following a doubling of atmospheric CO2 concentration”. The policy discussion in the press release, therefore, does not appear warranted by the paper’s content.
AND NOW FOR SOME MORE FUN
The mainstream media and blogosphere have ramped up their pathetic alarmist proclamations in response to Resplandy et al. 2018. Headline examples (my boldface):
- The Washington Post: Startling new research finds large buildup of heat in the oceans, suggesting a faster rate of global warming Subtitle: The findings mean the world might have less time to curb carbon emissions.
- Scientific American: The Oceans Are Heating Up Faster Than Expected
- CNN: World’s oceans have absorbed 60% more heat than previously thought, study finds
- Daily Mail: Earth’s oceans ‘soak up 60% more heat than thought’ and it could mean the planet is warming FASTER than scientists predicted
- The New York Times: Taking the Oceans’ Temperature, Scientists Find Unexpected Heat
- New Zealand Herald: Ocean study’s climate change warning
- Los Angeles Times: Oceans warming faster than anticipated, giving even less time to stave off worst impacts of climate change, study finds
- Fortune: Earth’s Oceans Have Built up 60% More Heat Than Previously Thought, Researchers Say
- CBS News video through YouTube (Caution: 6+ minutes of yawn-inducing video): Oceans warming faster than previously thought, study finds
Only CNN and the Daily Mail were foolish enough to repeat the “Imagine if the ocean was only 30 feet deep…” quote in their articles.
Do the authors of the headlines realize that when they claim things like “faster than scientists predicted” and “scientists find unexpected heat” they’re actually pointing out flaws in climate science?
And now for the headline that takes the prize for alarmism. The use of the word “horrific” must come from the proximity to Halloween.
Newser: Ocean Study Has Horrific Implications for Climate Change Fight Subtitle: Heat is going into oceans, not space, researchers say
KEVIN TRENBERTH OF MISSING-HEAT FAME WAS A CO-AUTHOR
[UPDATE Correction: I misread the Scientific American article. Trenberth was not a co-author of Resplandy et al. 2018. Oops.]
Kevin Trenberth of NCAR wasn’t mentioned as a co-author in the press release, so it was an unexpected treat to find Kevin Missing-Heat Trenberth was part of the paper’s team. To add icing to the cake, Scientific American interviewed him for their article The Oceans Are Heating Up Faster Than Expected (My boldface):
Kevin Trenberth of NCAR, another of that study’s co-authors, noted that because the new research constitutes a novel approach, there are some uncertainties that still need to be resolved. But he said the results are generally compatible with those of his own research.
The findings “have implications, because the planet is clearly warming and at faster rates that previously appreciated, and the oceans are the main memory of the climate system (along with ice loss),” he told E&E News by email. “The oceans account for about 92% of the Earth’s energy imbalance. This is why we are having increased bouts of strong storms (hurricanes, typhoons) and flooding events.”
Hmmm, “generally compatible with those of his own research.” I believe “generally compatible” is as weasel-wordy as weasel-wordy gets.
What seems to have eluded the authors of the articles is that the oceans can only release heat to the atmosphere at their surfaces, and surface temperatures were not addressed by Resplandy et al. 2018.
Many thanks to Larry Kummer of FabiusMaximus.com for alerting WUWT to the paper and the overreaction by the media, and as Larry noted in his original email:
Got to love how authors today are explicit about their results being “policy-relevant.” Although that reduces my confidence in their objectivity.
Thank you, oceans, for, as “they” say, absorbing most of (more than 90%) of the heat associated with human-induced global warming.
That’s all I’ve got. And to answer someone’s possible question, I have no intention of downloading and examining Resplandy et al. 2018.
And again, thank you, Larry.
STANDARD CLOSING REQUEST
Please purchase my recently published ebooks. As many of you know, this year I published 2 ebooks that are available through Amazon in Kindle format:
- Dad, Why Are You A Global Warming Denier? (For an overview, the blog post that introduced it is here.)
- Dad, Is Climate Getting Worse in the United States? (See the blog post here for an overview.)
To those of you who have purchased them, thank you. To those of you who will purchase them, thank you, too.
[UPDATE: Added a bracketed correction in response to a comment.]
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UPDATE 2 TO POST: I acquired a copy of the Resplandy et al. 2018 paper. So much for my intent not to examine it. Toward the end of the paper, the authors discuss how their new estimate of ocean heat uptake impacts estimates of climate sensitivity:
Ocean heat uptake, sea level and climate sensitivity. Climate sensitivity has been estimated to fall within the range of +1.5 K to +4.5 K for a doubling of CO2 (ref. 1). The impact of an increase in the ocean heat uptake on the effective equilibrium climate sensitivity (the apparent equilibrium climate sensitivity diagnosed from nonequilibrium conditions) can be estimated using a cumulative approach on the Earth energy balance (see Fig. 2 in ref. 1):
where N is the global heat imbalance, which mostly consists of the ocean heat uptake; F is the radiative forcing (in W m−2); ΔT is the increase in surface temperature (in K) above a natural steady state; and α is the climate feedback parameter (in W m−2 K−1), which is inversely proportional to the effective equilibrium climate sensitivity1. All terms in equation (3) are time integrated over the period of interest.
Reference 1 = 1. IPCC. Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) (Cambridge Univ. Press, Cambridge, 2013).
And they continue on the topic of climate sensitivity:
The IPCC Fifth Assessment Report gives a ΔOHC of 0.80 × 1022 J yr−1 for 1993–2010, which is about 0.5 × 1022 J yr−1 lower than the ΔOHC that is compatible with both APO and hydrographic constraints. By applying equation (3)1 to surface temperature data over the period 1991–2016 (HadCrut4 version 4.5, ref. 64, with a 1860–1879 preindustrial baseline), we found that the upward revision of the global heat imbalance, N, by +0.5 × 1022 J yr−1 pushes up the lower bound of the equilibrium climate sensitivity from 1.5 K back to 2.0 K. An increase of the lower bound from 1.5 K to 2 K corresponds to a need to reduce maximum emissions by 25% to stay within the 2 °C global warming target (because of the almost linear relationship between warming and cumulative emissions; see Fig. SPM.10 in ref. 1). This corresponds to a reduction in maximum allowable cumulative CO2 emissions from 4,760 Gt CO2 to 3,570 Gt CO2.
I’ll let you readers comment. I’m done with Resplandy et al. 2018.