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Last year, twenty thousand peer reviewed studies on ‘climate change’ were published. No single person can keep track of all those – you’d have to read 55 papers every single day. (And, by the way, that huge mass of publications is why climate deniers will always find something to cherry-pick that suits their agenda.) That is why climate assessments are so important, where a lot of scientists pool their expertise and discuss and assess and summarize the state of the art.
So let us have a quick look what last year’s climate assessments say about the much-discussed topic of whether the Atlantic Meridional Overturning Circulation (AMOC, a.k.a. Gulf Stream System) has already slowed down, as predicted by climate models in response to global warming.
First, there is the IPCC 1.5 °C report (SR15) prepared for the Paris Climate Agreement and published in September 2018. It doesn’t say all that much about the AMOC, given that it is not a full IPCC assessment, but it does say this:
It is more likely than not that the Atlantic Meridional Overturning Circulation (AMOC) has been weakening in recent decades, given the detection of the cooling of surface waters in the north Atlantic and evidence that the Gulf Stream has slowed by 30% since the late 1950s (Srokosz and Bryden, 2015; Caesar et al., 2018). There is only limited evidence linking the current anomalously weak state of AMOC to anthropogenic warming (Caesar et al., 2018). It is very likely that the AMOC will weaken over the 21 st century. […]
Weakening of the Atlantic Meridional Overturning Circulation (AMOC) is projected to be highly disruptive to natural and human systems as the delivery of heat to higher latitudes via this current system is reduced.
[Note: those “30% since the late 1950s” are probably in error; they are not supported by either of the two references provided.]
Then, in November, the 4th US National Climate Assessment was published that had been two years in the making. It says:
The primary concern related to ocean circu-lation is the potential slowing of the Atlantic Ocean Meridional Overturning Circulation (AMOC). An AMOC slowdown would affect poleward heat transport, regional climate, sea level rise along the East Coast of the United States, and the overall response of the Earth’s climate system to human-induced change. […]
As the atmosphere warms, surface waters entering the North Atlantic may release less heat and become diluted by increased freshwater melt from Greenland and Northern Hemisphere glaciers. Both of these factors would slow the rate of sinking and weaken the entire AMOC.
Though observational data have been insuffi-cient to determine if a long-term slowdown in the AMOC began during the 20th century, one recent study quantifies a 15% weakening since the mid-20th century and another, a weakening over the last 150 years. Over the next few decades, however, it is very likely that the AMOC will weaken.
Finally, Future Earth (a global Earth science research programme) and the Earth League (a grouping of leading institutions and individuals in the Earth sciences) have issued a climate science update for the Katowice climate summit in early December, called 10 New Insights in Climate Science 2018. It says:
A weakening of the Atlantic overturning circulation, often referred to as the Gulf Stream system, has been expected from model simulations. Recent studies confirm that it has slowed down by 15% since the middle of the 20th century and is at its weakest in over a thousand years. This is already having observed effects, such as extreme weather in Europe, and further weakening is expected to strongly affect European weather as well as exacerbating sea-level rise at the east coast of North America.
In December also a new study – too late to be included in the assessments – was published by Thibodeau et al in Geophysical Research Letters, which further supports an unprecedented AMOC weakening during the past decades. The authors write:
In this study, we used geochemical evidence to highlight a slowdown in the North Atlantic Ocean circulation over the last century. This change appears to be unique over the last 1,500 years and could be related to global warming and freshwater input from ice sheet melt.
Our regular readers know that one of my topics of interest is the stability of the Gulf Stream System – I’ve worked on this on and off for over 25 years, ever since finishing my PhD in physical oceanography. So let me add my own comments on the findings cited above.
First of all, while we don’t have regular direct measurements of the AMOC going back throughout the 20th Century, indirect evidence for an AMOC slowdown is not new. Dima and Lohmann already concluded in 2010 that “the conveyor has been slowing down over the last seven decades” (where ‘conveyor’ refers to the AMOC).
Strangely, this finding was not discussed at all in the fifth IPCC report published in 2013. Therefore, the IPCC now finding that an ongoing slowdown is “more likely than not” is progress, yet still a very cautious statement. Likewise the statement about the “limited evidence” for the slowdown being human-caused is also very cautious. Why do I find this overly cautious?
The main points there are that an AMOC slowdown leads to a particular fingerprint pattern in sea surface temperature change – which is basically what Dima and Lohmann already identified, and this pattern is predicted by high-resolution climate models in response to rising greenhouse gases, and it is also found in the observations. There is no known alternative explanation for what might cause this fingerprint. That fingerprint is not subtle: it is so strong that the subpolar Atlantic is the world’s only region which has resisted global warming over the past hundred years and even has cooled down, reaching record low temperatures in 2015 when the globe as a whole was record-hot.
In fact, the strength of this pattern and the conclusion that it corresponds to a 15% AMOC slowdown just matches the median slowdown found in the historic climate runs of the CMIP5 climate models – in other words, it is exactly what the models predict as a response to human-caused climate change. The physical mechanism is understood – how warming and ice melt weakens the AMOC (and that these factors are human-caused), and how an AMOC weakening causes the observed surface temperature fingerprint. In addition, there are several independent data sets that show this slowdown to be unprecedented for at least a millennium.
In IPCC jargon, personally I would therefore give the statement that the AMOC has slowed down since the early-mid 20th , and that this is at least partly human-caused, a “very likely” rating.
Two recent papers, Zanna et al. (2019) (hereafter ZKGIH19) and Gebbie & Huybers (2019) (hereafter GH19), independently reconstructed ocean heat content (OHC) changes prior to the instrumentally-based records (which start ~1950). The goals (and methodologies) of the two papers were quite different – ZKGIH19 investigated regional patterns of ocean warming and thermal sea level rise, while GH19 analyzed the long-term memory of the deep ocean – but they both touch on the same key questions of climate forcing and response.
The two studies independently show that subsurface temperature change is well described on century-long timescales by surface imprints that are transported by the modern ocean circulation. Both studies highlight the following points: changes in ocean circulation have very little impact on global OHC changes, and that the deep ocean adjusts slowly to surface temperature changes, showing a slow emergence of anthropogenic trends at depth in the recent decade.
The two methodologies are distinct: ZKGIH19 uses a Green’s function approach to derive the imprint on the deep ocean of changes in surface fluxes from the ECCO project (a reanalysis model that uses modern ocean data to reconstruct a state estimate of the ocean circulation). This is then combined with the history of observed SST (HadISST2) to infer the deep ocean changes.
GH19 use a functionally similar inversion technique for ocean tracers (outlined in Gebbie and Huybers (2011)) to create a forward model that produces an estimate of deep ocean changes given the surface forcing. They then constrain this estimate using the difference between the HMS Challenger data (1872–1876) and modern WOCE data to produce an optimised estimate of ocean temperature structure going back to 15 CE. Unfortunately, there isn’t an uncertainty quantification that goes with this.
For 1955–2017, both estimates in the upper and deep ocean are similar to estimates made by infilling the available 3D time-dependent ocean temperature observations (GH19: 0.35 W/m2, ZKGIH19: 0.33 ± 0.07 W/m2 (one sigma)). The warming between 1921-1946 is also consistent between both estimates (ocean heat uptake GH19: 175 ZJ, ZKGIH19: 145±62 ZJ (1 sigma)) and is comparable to the 1990-2015 time interval (GH19 = 135 ZJ, ZKGIH19: 153 ± 44 ZJ). Even when the time interval is pushed back to 1880, the two numerical estimates of ocean heat uptake are self-consistent.
Below 2 kilometers depth and before 1880, the two estimates show larger differences. For the time period, 1871-2015, the GH19 total estimate (570 ZJ) is bigger than ZKGIH19 (436 ± 91 ZJ), but not significantly so. (Note that GH19 ends in 2015, ZKGIH19 in 2017.)
The differences probably have 2 major causes: 1) the lingering influence of surface climate from before 1870, and 2) discrepancies in the estimated surface warming in the late 19th century. Below 2 kilometers depth, the heat uptake has differing signs for the interval, 1871-2015 in the two analyses (GH19: -25 ZJ, ZKGIH19: approx. 14 ZJ ± 6 ZJ), due to a cooling up from 1971 until 1950 in the deep ocean in the reconstruction in GH19 compared to ZKGIH19. Surface warming is stronger in GH19 in the late 19th century due to ingestion of data from the HMS Challenger observations and Ocean2k paleo reconstructions (though errors are included in the reconstructions), while ZKGIH19 only used sea surface temperatures starting from 1871. The differences could also be due to the different transport models, GH19 used WOCE data in parts of the 1990s, while ZKGIH19 used ECCO over 1992-2003 (which nonetheless incorporated WOCE data as part of it’s input).
ZKGIH19 shows that regional changes in ocean circulation have an imprint on patterns of OHC and thermosteric sea level in the Atlantic Ocean over 1955-2016. By comparing with observations, they argue that up to half of the observed ocean warming and thermosteric sea level trends between 20oS and 50oN are due to time-dependent ocean horizontal and vertical redistribution. They showed that there are large variations in patterns of warming between the early and late periods. GH19 mostly focus on the deep Pacific and showed large OHC cooling trends over the past century, (but did not show global latitudinal distributions). They argue that the deep Pacific cooling is a signature of long-term adjustments of the ocean after the Little Ice Age. ZKGIH19 shows basin-scale estimates but those include the Southern Ocean and cannot be directly compared to GH19 basin estimates which are north of 45oN. A more apples-to-apples comparison will take a bit more effort to produce.
(Additional text from gavin)
Given the average transit time for the deep Pacific (1000’s of years), it is expected that the deep Pacific won’t be in equilibrium with surface climate changes over shorter time scales. GH19 are not the first to quantify this deep dis-equilibrium (previous work had looked at the เว็บพนันบอล ดีที่สุด 2019lingering impact of Tambora in 1815 for instance), but this might be the estimate most consistent with the (sparse) early observations. The caveats are (as usual) there are still imperfections in the ocean models being used and the systematic biases in old observations are always being looked at. The differences between the two studies are thus understandable from their study design.
These long-term estimates are however an interesting new metric to compare to the models. Just for fun, I plot (below) the total ocean heat uptake from the historical GISS CMIP5 model ensembles (normalized to 1871). These ensembles have two different ocean models (version R and version H), and two different treatments of atmospheric composition (non-interactive and interactive) and start from quasi-equilibrium in 1850. There are still residual drifts in the deep ocean which have been subtracted out using the control runs. The ocean model definitely makes a difference, and the GISS-E2-R runs had excessive mixing down of heat into the ocean (in the CMIP6 version this is reduced). Both sets of simulations have more cumulative heating than either the ZKGIH19 or GH19 estimates, though whether that is typical of the CMIP5 ensemble, or the new CMIP6 runs, is still to be determined. Note that an excessive uptake of ocean heat would be associated with a lower transient climate response (TCR), but the match in the upper ocean for more recent periods suggests it is likely that there may be issues with early 20th C forcings. It will also be interesting to see whether the longer millennial simulations (starting in 850 CE) might have a different pattern… Watch this space!
Guest commentary from Eric Guilyardi (IPSL) and Valérie Masson-Delmotte (IPSL/IPCC)
[This is a translation of an article in Le Monde (Jan 11).]
In recent weeks in France, there has been a profusion of articles about the “climate scientist blues” (Le Monde 21/Dec, JDD 9/Dec, France Info 26/Sep), which has apparently affecting them “scientifically”. This follows a spate of similar articles in the US and Australian media (Esquire, 2015; The Monthly, 2018; Sierra Club Magazine, 2018). But what is the point of knowing the mood of scientists, or whether so-and-so is optimistic or pessimistic?
Are epidemiologists asked if they are depressed when they anticipate an epidemic outbreak, or meteorologists polled about their anxiety because they predicted a storm or a heatwave? In these cases, society organizes to manage the risk related to these forecasts (orange or red alerts, weather watches and warnings) and does not care about the emotions of the scientists. The main reason most climate scientists come out of the lab and engage publicly is not to share their subjective emotions about the state of the world, but rather to discuss the results and consequences of our science.
On an individual basis, the scientists can sometimes be proud if their forecast has been useful for better managing the consequences of an event, or be upset that it wasn’t, but the quality and relevance of their expertise does not depend on their state of mind. But the principal role for climate scientists is to inform the public debate about the outcome of collective science efforts and the risks associated with the different trajectories of greenhouse gas emissions, not how they feel about it.
More broadly, climate change science also provides multiple insights into how to manage climate risks. It offers new opportunities for partnership between the scientific researchers and society as a whole to help make decisions in a context of uncertainty about the future evolution of the climate, especially at the local and regional scale. New knowledge is emerging on how to build ethical and just transitions, to maximize the synergies between climate action and the other aspects of sustainable development.
With more than 20,000 scientific publications each year with the key word “climate change”, the production of new knowledge is proceeding quickly. The challenge in interpreting this is not the state of mind of researchers, but the regular synthesis of this knowledge and how to share it with the whole of society in order to encourage solutions to manage climate risks, preserve biodiversity, and allow everyone to live with dignity by improving the well-being of all.
As the last IPCC special report on 1.5°C reminded us, the real issue is that we currently face three types of major risk. The first risk is related to each additional fraction of warming, with humanitarian, agricultural, environmental and migratory crises, increasingly challenging to manage. The second risk is the burden passed on to today’s younger generations, who would face the triple trouble of coping with the impacts of global warming; having to accelerate abruptly the transitions to a low-carbon economy if we delay in putting it in place; and lastly, to have to choose options that are potentially very risky for both biodiversity (for example through massive use of biomass energy) or global governance (for example, geo-engineering) in an attempt to contain global warming or its consequences. The third risk is rapid transition to the economy and the current global financial system through the ‘stranded assets’ of capital invested in the fossil fuel industry.
The real challenge is therefore the mobilization of collective intelligence and democratic debate on the choices of risk that we are willing to take. The Paris Agreement seems to indicate that nations who have ratified it want to avoid the first two risks and organize themselves to face the third.
What if the focus on the moods of climate scientists was a way to disengage emotionally from the choices of risk or solutions to global warming? Since the experts are worrying about it for us (it’s their daily life, isn’t it?), let’s continue our lives in peace. If feelings and expressing emotions – fear, anger, anguish, feelings of helplessness, guilt, depression – in the face of risks are legitimate, even necessary, to take action demands that we go beyond that. Catastrophism often leads to denial, a well-known psychic mechanism for protecting oneself from anxiety. Managing risk is part of our daily lives and supposes that we are not in such denial (active or passive) as it prevents clear and responsible action. Because we know that many hazards carry predictable risks, human societies have learned to anticipate and cope, for example, to limit the damage of storms or epidemics. The challenge of climate change is to build a strategy not in response to an acute and clearly identified risk, but in anticipation of a gradual, chronic increase in climate risks.
The climate scientists are alright (mostly), but that’s not the important question. The dispassionate management of climate risk will require that everyone – citizens, decision makers, teachers, intermediate bodies, companies, civil society, media, scientists – in their place and according to their means, take the time for a collective reflection, first of all through mutual listening. The news shows it every day: this process is hobbling along, too slowly for some, too fast for others. It will need to overcome emotional reactions, vested interests, and false information from the merchants of doubt. Those who are unable to review their strategy and have everything to lose from the exit from fossil-fuel based energies will use nit-picks, manipulation, short-termism, and promote binary and divisive visions, all of which undermine trust and pollute the debate. But despite that…
Every degree of warming matters, every year counts, every choice counts. The challenge is immense because of the nature and magnitude of the unprecedented risk. It requires doing everything to overcome indifference and fatalism.
Given some unexpected down time this month (and maybe next month too!), I’ve been trying to go through key old posts on this site. The basic idea is to update links to other sites, references and figures that over the years have died (site domains that were abandoned, site redesigns, deliberate deletions etc.). Most notably, the IPCC website recently broke all the existing links to elements of the reports which we had referenced in hundreds of places. Thanks guys!
Some folk have been notifying us of issues they found (thanks Marcus!) and I’ve been fixing those as they come up, but obviously there are more. Links to old blog posts from Deltoid, Scienceblogs, Pielke Sr. or Prometheus generally don’t work anymore though they can sometimes be found on the wayback machine. It turns out a lot has changed since 2004 and many hotlinked images in particular have disappeared.
It’s obviously not worth finding replacements for every dead link, but digital uncluttering and fixing up is useful. So, please use this thread to notify us of any useful fixes we can make (and if you have an updated link,, that’d be perfect). Additionally, please let us know if any of the old content is still useful or interesting to you. We know there is still substantial traffic to the back catalog, so maybe it should be highlighted in some way?
To those of you who might ask whether blogging still brings me joy… of course it does!
an initial claim of imperfection spiced up with insinuations of misconduct, coordination with a breathless hyping of the initial claim with ridiculous supposed implications, some sensible responses refuting the initial specific claims and demolishing the wilder extrapolations. Unable to defend the nonsense clarifications are made that the initial claim wasn’t about misconduct but merely about ‘process’ (for who can argue against better processes?). Meanwhile the misconduct and data falsification claims escape into the wild, get more exaggerated and lose all connection to any actual substance.
The outcome was easy to predict:
the issues of ‘process’ will be lost in the noise, the fake overreaction will dominate the wider conversation and become an alternative fact to be regurgitated in twitter threads and blog comments for years, the originators of the issue may or may not walk back the many mis-statements they and others made but will lose credibility in any case, mainstream scientists will just see it as hyper-partisan noise and ignore it, no papers will be redacted, no science will change, and the actual point (one presumes) of the ‘process’ complaint (to encourage better archiving practices) gets set back because it’s associated with such obvious nonsense.
But I missed out the very final outcome which I should have been able to predict too: a report, commissioned from learned experts, who spent months poring over the details (including more than 600,000 emails!) and in the end, concluding there was nothing significantly wrong in anything Karl et al did.
In it the authors make some sensible recommendations to clean up the thicket of conflicting requirements at NOAA for publishing science papers, they spot one mistake made by Karl et al (submitting to Science the day before the NOAA internal review was officially completed), but overall find no substance to the allegations of “thumbs on the scale”, no improper interference by politicians, no rush to publish to influence political discussions, no data tampering, no missing archives. Nothing.
But there is one curious revelation. It turns out that the person in charge of the NOAA internal review about which John Bates was so concerned was…. John Bates!
And even more curiously:
“The MITRE Committee learned that the internal review, later criticized by Bates, was conducted and approved under his own authority. The MITRE Committee found no evidence that Bates ever mentioned this fact in his blog, email, or anywhere else in his discussion of the matter in public.”
Did he mention this to David Rose or Judith Curry in private perhaps? If so, you’d think that they would have publically said so. If not, it adds one more misrepresentation to the pile.
What a colossal and counter-productive waste of everyone’s time.
This year’s first open thread on climate science topics. Usual rules apply – and let’s make a particular effort to stay substantive and not devolve into empty bickering (you still have Facebook for that).
Any expectations or predictions for climate science in 2019?
The underlying mission of my job is to safeguard lives and property through climate change adaptation based on science. In other words, to help society to prepare itself for risks connected with more extreme rainfall and temperatures.
For many people, “climate” may seem to be an abstract concept. I have had many conversations about climate, and then realised that people often have different interpretations. In my mind, climate is the same as weather statistics (which I realise can be quite abstract to many).
To avoid miscommunication, I want to make sure that we are on the same page when I discuss climate. Maybe it helps if I talk about more familiar and specific aspects, such as the temperature, rainfall, snow, or wind?
Data, facts, and climate
But I have a challenge because data and facts are often not valued and engaging. This is a general problem when it comes to climate change, as there are probably few other scientific disciplines that have shared more data then the climate science community.
There is a bounty of sites that will give you access to free and open data, however, the access does not necessarily mean that it’s easy make use of the information embedded in the data. Often it requires a bit of work and skills in order to download and visualize it.
For instance, there are some great web-portals, such as NASA/GISS, Global Historical Climate Network (GHCN), and the KNMI ClimateExporer. These portals are extremely useful for scientists and experts (they also give the contrarians numbers on which to build their misconceived ideas), but they may be too complicated for a lot of people.
There are also many stories about climate in the mass media these days, and I have started to ignore many of these reports because they are not all relevant. So, if climate is perceived as both an abstract concept and not always relevant, then it’s a real challenge to engage people in the question about climate change.
See how rainfall and temperature have affected you
On the other hand, people care about local issues where they live and have a direct connection to their lives. So perhaps the message about climate change is perceived as more relevant when people can see the historical temperatures and rainfall near where they live?
Based on these thoughts, we wanted to try to make a simple app without jargon, acronyms and technical terms that enables the (wo)man in the street to explore the precipitation and temperature measured in her/his vicinity.
One intention with this app was to start with a simple overview picture of the measured climate data. It is important not to overwhelm at first sight, but let people understand the depth of the data once they start to explore it.
The data is not perfect
When viewing these data, it is important to be aware that there may be an occasional error in the measurements, but showing the data and letting people explore it may bring such errors to our attention.
You are also likely to come across some records with a misleading trend estimate if you study the data, because there are some data records for stations that have been relocated during the period of measurement, the instrument has been replaced, or the observational practices has been changed.
The Open Climate Data Prototype (OCDP), shown in the iFrame below, has been designed for a project in Mozambique, but is being tested for Norway. We wanted to experiment with ways to make the climate information more easily available for people.
An open and interactive app
You can change the main settings of this app by clicking on the icon with three horizontal lines in the top left corner, for instance to change the region/country or the element. It also lets you study the metadata as well as summary statistics.
The graphics is interactive, and there are three tabs showing different aspects of the data. You can also explore daily, monthly, seasonal or annual temperature or precipitation for a selection of locations in different parts of the world (e.g. a selection from North America, Australia, Eurasia, Africa, Asia).
After we developed this prototype, we realised that there was a similar app called ACD-App (GitHub) of the Southern African Science Service Centre for Climate Change and Adaptive Land Management (SASSCAL). However, I don’t know if it is up and running as a web-based as well.
Both apps are developed in R and R-shiny, and can in principle run on a stand-alone desktop/laptop as well as on a server. SASSCAL is a joint initiative of Angola, Botswana, Namibia, South Africa, Zambia, and Germany in response to the challenges of global change, and is highly relevant to our capacity-building project in Mozambique.
Know the past before you can know the future
The study of past climatic variations and trends is necessary before we can make projections for the future. The historical data provide us with important clues about how different conditions interact, as well as being the basis for model evaluation. They are also important for studying the impact of local climate fluctuations on society, such as crop yields.
“Shall I bend low and in a bondman’s key,Shylock (Merchant of Venice, Act 1, Scene 3)
With bated breath and whisp’ring humbleness…?”
As dark nights draw in, the venerable contrarians at the GWPF are still up late commissioning silly pseudo-rebuttals to mainstream science. The latest, [but see update below] which no-one was awaiting with any kind of breath, is by Dr. Ray Bates (rtd.) which purports to be a take-down of the recent #SR15 report. As Peter Thorne (an IPCC author) correctly noted, this report is a “cut-and-paste of long-debunked arguments”. I’ve grown a little weary of diving down to rebut every repetitive piece of nonsense, but this one has a few funny aspects that make it worthwhile to do so.
When they go low, we go “sigh…”.
Peter wrote a short rebuttal himself and notes a remarkable display of chutzpah by Bates. Bates quotes a line from the AR5 SPM:
It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together.
And then states “This statement did not necessarily attribute all the observed post-1950 warming to anthropogenic effects”. This is of course true. You actually need to read the next line for that:
The best estimate of the human-induced contribution to warming is similar to the observed warming over this period.
But instead of noting that (or the substantive discussion in Chapter 10 that supported it), he claims that
In contrast to this caution, SR1.5 portrays all the global warming observed since the late 19th century as being human-induced (see Figure 1). This major departure from the Fifth Assessment is presented without any rigorous justification.
This is categorically, absolutely, and totally, untrue. The starting point for SR15 is actually exactly what was in AR5 together with more recent literature. Now, this is not the first time that someone has apparently “misunderstood” these lines. I had a substantial back and forth about them with Judith Curry a few years back (see here, and เว็บพนันบอล ดีที่สุด 2019here). [Unsurprisingly perhaps, she thinks Bates’ report is an “excellent analysis“].
It gets better (and by that I mean worse). Bates then comments on Figure SPM1 of the SR15 and says:
The agreement shown in the figure between the observations (with interannual variations smoothed out) and the mean of the climate simulations (produced by global climate models; GCMs) is close, suggesting that strong confidence can be placed in both the indicated acceleration of the warming and its modelled anthropogenic origin.
… except that, this isn’t what is shown in Fig SPM1 at all. Instead, alongside the observations is an estimate of the attributable warming to anthropogenic effects from Haustein et al. (2017), which is not the ‘mean of GCM simulations’ in any respect.
It gets even better. Later in Bates’ article, he is quite enamored by the climate sensitivity results of Lewis and Curry (2018) but doesn’t seem to realise that their results assume that all of the trends since the 19th Century are forced. The exact conclusion he rails against in the first section!
The other paper he likes for it’s climate sensitivity work is his own somewhat obscure effort (Bates, 2016), which argues for an ECS near 1K, despite the clear evidence that the planet has already warmed up by that, with a net forcing substantially less than 2xCO2, and with an ongoing energy imbalance (as evidenced by observed increases in Ocean Heat Content). This, to be gentle, is pretty much impossible.
Unsurprisingly, this isn’t the estimate of OHC that he mentions. He instead pulls another sleight of hand by referencing a result from Laloyaux P., et al. (2018). This is a paper presenting a new (and impressive) coupled data assimilation scheme from ECMWF, but Bates grossly misrepresents the results. The figure he shows is first panel from their figure 10:
He uses this to claim that “the natural variability of the global SST is greater than had previously been estimated”, when a) this doesn’t show SST (though it is related), b) much of the variance pre-1980 is unphysical model drift, and c) the increases in the full depth OHC actually match direct observational estimated (which is unsurprising since this is a data assimilation exercise).
The rest of the report goes from the sublime (just kidding) to the ridiculous (e.g. using a paper by Nicola Scafetta as an authoritative (!) source – anyone heard of autocorrelation or over-fitting?) and cherry picking the few datasets that minimise current changes. He cut-and-pastes a figure from John Christy that we have oft criticised before. He misreads the climate model tuning paper by Hourdin et al (2017) to claim that all CMIP5 models tuned their results to match the 20th Century trends [Narrator: they did not]. But even if it actually were true, it still wouldn’t impact the results in the first figure he attacks because that doesn’t show the CMIP5 models at all. He appears to be unaware of this.
Overall, this is basically a dialed-in work-for-hire. It’s incoherent, inconsistent, a little bit funny and adds nothing to our understanding of the science behind the SR15 report, or indeed any aspect of the attribution issue.
Since I started with a Shakespearean quote, I’ll finish with another one that is more apropos:
It is a taleMacbeth, Act 5 Scene 5
Told by an idiot, full of sound and fury,
Update Jan 2019: The original report from Bates (here) has now been replaced with one that tries to fix the more egregious errors, er… I mean that makes “clarifications that arose in the context of discussions with colleagues”. Lol.
Guest commentary by Lauren Kurtz
The Climate Science Legal Defense Fund (CSLDF) protects the scientific endeavor from anti-science attacks. Since our founding in 2011, we’ve assisted hundreds of scientists with issues ranging from invasive open records requests to death threats.
As part of this work, our staff will be at the American Geophysical Union Fall Meeting from December 10-14, offering free legal services to scientists and leading sessions on how to get involved in the policymaking process and how to be an expert witness.
For those who won’t be at the meeting — and with 2019 around the corner — we put together a list of suggested New Year’s resolutions for scientists. Adopting these best practices will help you reduce your risk of being harassed or attacked.
Do not use professional email accounts for personal emails and vice versa.
Climate scientists and other researchers have been increasingly targeted via misuse of the legal system. Separating personal and professional emails can reduce the likelihood that your personal correspondence will be caught up in legal actions. For example, many publicly-funded scientists have been targeted under open records laws, which only affect records related to government-funded work. Keeping personal and professional correspondence separate helps ensure that your personal communications stay private.
It’s also important to be clear about when you are operating in your personal capacity versus your professional role. If you give an interview, post on a blog, write an op-ed, or sign a petition or open letter, make it obvious if you are speaking for yourself and not as part of your professional role.
In particular, any advocacy or activism that is not done on behalf of your institution should be done on your personal time, on your personal email account and personal devices, and without using your work affiliation (if possible). If you must state your title or employer for identification purposes, clarify that you do not speak on behalf of your institution. This will help to prevent any allegations of misuse of grant funding for non-grant related purposes, and help avoid allegations of employment violations.
In general, the First Amendment limits the government’s ability to suppress speech. It protects public employees who speak (i) in their private capacities, (ii) on their own time, (iii) about matters that concern the public, against improper censure by the government; it does not constrain private employers from disciplining employees for their public speech. (Public employees include federal agency workers, public university professors, and sometimes others who receive government funding.)
To better understand your legal rights, and legal obligations, please visit the resources section of our website, which has a variety of educational materials for scientists. If you would like printed copies of these resources, we’ll have some available at booth 1047 in the AGU Exhibit Hall.
Seek counsel if you’re worried you’re becoming the target of harassment or intimidation (including receiving a legal notice that seems politically motivated), or if you want to better understand the legal landscape as it relates to your work. Your institution likely retains legal counsel that you can contact, but it is important to remember that your institution’s counsel represents the institution’s legal interests, which may differ from your own.
You can always contact CSLDF, where our mission is to provide free legal counsel to scientists targeted as a result of their work. Call us at (646) 801-0853 or email email@example.com.
We look forward to seeing many RealClimate readers at our AGU sessions and booth, and thank you for your continued support of our work.