.

Friday, August 3, 2018

It was a warm, dry July in Canberra (and kangaroos have fur)

Sou | 1:47 AM Go to the first of 33 comments. Add a comment
Eric Worrall says there are "Kangaroos Dying of Cold" in Canberra. That's a good one. Eric doesn't know much about Australia and less about kangaroos. I don't know how long he's lived here, but you'd think he'd have picked up some knowledge about the place.

Did you know that when kangaroos can't find enough food where they normally go, they'll look elsewhere? It's the same for for a lot of animals - yeah, really.

There's a bad drought in parts of Australia at the moment. This is affecting wildlife as well as farmers and their stock. I'll talk about the Australian Capital Territory where Australia's capital city, Canberra, is located because there is a bit of idiocy about it being put about by deniers.

Monday, July 30, 2018

Watts up with that vs Google vs Climate Change

Sou | 12:26 AM Go to the first of 19 comments. Add a comment
There's consternation at the climate conspiracy blog WattsUpWithThat.com (WUWT). Kip Hansen, a random denier dude, is ropeable. He's most upset because, in June this year, WUWT had a big drop in click-throughs from Google. A 30% drop, according to Kip (Google cache here :D).

Now this isn't about paid-for click-throughs (via Google AdWords). It's just about the freebie service that everyone gets. Here's his evidence that the Google algorithm is working better. Feel free to celebrate or commiserate.

Chart source: Wattsupwiththat.com

You probably noticed that, as climate science deniers tend to do with temperature charts, Kip's 30% measurement started at an unusually high point. (He may not have been able to get much earlier data because WUWT moved to a new server at the end of May this year and Anthony Watts might not have kept stats the same way on the old server. Who knows?)

Sunday, July 29, 2018

This crazy climate! What do Anthony Watts and Alex Jones have in common? Prison Planet.

Sou | 2:20 PM Go to the first of 11 comments. Add a comment
Some of you might think HotWhopper may on occasion go overboard reporting the lies, duplicity and straight up weirdness of deniers. That's not so. If anything, the articles here underplay the weirdness of deniersville. Some of what goes on in climate conspiracy land is not fit for publication on normal blogs.

WUWT has recently reinvigorated its crusade to libel or solicit libel of prominent climate scientists and climate hawks. In the last couple of days there have been articles about Michael Mann and Ben Santer, for example. When all else fails, disinformers turn to lying smears.

But that's not all.

WUWT is now using US conpiracy theorist Alex Jones' Prison Planet as a source!

Saturday, July 28, 2018

Some bloke called Marcel Crok plays a cruel climate joke on Anthony Watts at WUWT

Sou | 3:24 PM Go to the first of 26 comments. Add a comment
This is sad. A ratbag from Europe, Marcel Crok, who is considered by Anthony Watts to be a "good friend" (enough said), has written to Anthony asking him to consult his network of "experts" (cached version).

What a horrid and cruel trick Marcel is playing on his supposed "good" friend.

Of course, it might be Marcel is unfamiliar with WUWT and is not a very close friend of Anthony's. He may not know that Anthony has no "network of experts". On the other hand, Marcel could have been wondering what the dregs of climate conspiracy land will say about the wave of extreme events happening around the world. (As far as I can make out, Marcel is a freelance writer who could be considered the equivalent of David Rose, who in turn has a well-earned reputation as a climate disinformer from the UK.)


Wednesday, July 25, 2018

The global inconsistency of climate science denier, Larry Hamlin, at WUWT

Sou | 9:57 PM Feel free to comment!
This is rich.

Yesterday I wrote how climate disinformer Larry Hamlin picked out years of hot Junes in the USA and California, as if to argue that global warming isn't worth worrying about because there have been occasional hot Junes in California and the USA in the past. Today he wants to ignore local and go global (cached here).

In the last article I showed how, when you put Larry's USA/Californian June temperatures in the global context, it highlights the ridiculousness of deniers. Early last century the world as a whole was much colder than it is today. This century we're really getting a taste of what's to come. This past few weeks we've been getting a horrific taste of what's to come much more often, with deadly fires, drought, killer heat waves and floods widespread over the northern hemisphere, not to mention the drought back here in Australia. It isn't just hot in California and the USA, it's hot in lots of places as this map of June temperatures shows (from GISTemp).


US-centred climate change denial from the desperate deniers at WUWT

Sou | 2:24 AM Go to the first of 5 comments. Add a comment
While the distinctly unpresidential Donald Trump is desperate to deny he's in Putin's pocket, his zombie acolytes at WUWT are desperate to deny the world is warming. So much so that they are trying to deny that the weather lately has been quite extraordinary.

There are fires raging in Greece, where at least 74 people are feared dead. There has been a killer heatwave in Japan that broke high temperature records, has claimed at least 77 lives and sent more than 30,000 people to hospital. This follows the tragically disastrous floods that killed upwards of 200 people. Then there was the horrific tragedy in Laos, where monsoon rains led to 5 billion cubic metres of water flowing from a busted new hydro dam, killing who knows how many people and with hundreds missing and leaving 6,600 people homeless. (If the evacuation notice had not been sent out in advance the tragedy may have been even worse.)

In Sweden, which is suffering the worst drought since records began, there are terrible wildfires. In fact, much of Western Europe is facing yet another summer heatwave. In the far north of Finland, of all places, the temperature reached 34.3 C (94 F) the other day!

Monday, July 9, 2018

Climate conspiracy theorist Anthony Watts is hot and bothered by heat in California

Sou | 3:50 PM Go to the first of 24 comments. Add a comment
It's taking me a while to get back to blogging and there's a lot happening in the world to distract. I couldn't help but notice there is a lot of extreme weather around the world, the terrible floods in Japan, for example. If you're wondering how these examples of climate change are affecting climate science deniers, it's making them even loopier than normal.

Airport UHI disease breakout in Africa


Over at WUWT, Anthony Watts found another airport that had a sudden attack of airport UHI disease. You'll remember how there was an outbreak in Greenland back in 2013. This horrible disease only strikes on very hot days, apparently. Not even that. It only strikes on the very hottest of days according to Anthony's research. He said he his amazing finding was "based on hours of combing Google Earth and other sources". Yes, he really did spend "hours" trying to figure out a reason to discount a temperature reading for a weather station in Africa. He decided that on the particular day of the very high weather reading, possibly a record high reading, the weather station decided to act up.


Thursday, June 28, 2018

Pseudoscience in black and white, from Eric Worrall at WUWT

Sou | 8:34 PM Go to the first of 21 comments. Add a comment
Here's a small example of why one should avoid getting their science from pseudo-scientists. Eric Worrall is criticising an experiment that was designed to determine the impact of higher daytime temperatures on bees.

The scientists put some bees into boxes painted white and some into boxes painted black and monitored them for a couple of years.

Eric thought he found a fatal flaw. His criticism was this:
The team seem to have logged daily maximum temperature inside the boxes, but I didn’t see any attention to daily minimum temperature. Painting the boxes black would have caused higher maximum temperatures from absorption of sunlight in the daytime, but the black painted boxes would also have radiated heat faster at night.
Just in case you thought, maybe Eric was talking about the faster rate of cooling as the sun went down, he's not. He added a sentence so you'll not make any mistake:
So it seems possible that much of the damage to the bees in the black boxes was caused by colder night time temperatures, rather than warmer daytime temperatures.
Wrong! Both boxes would have around the same minimum temperature during the night.

Tuesday, June 19, 2018

2018 has the fourth hottest May on record

Sou | 1:45 AM Go to the first of 11 comments. Add a comment
Summary: May 2018 was the fourth hottest May on record. The 12 month period to May 2018 was the third hottest June to May period on record.

According to GISS NASA, the average global surface temperature anomaly for May was 0.82 °C, which is 0.09 °C less than the hottest - May 2016.

Below is a chart of the average of 12 months to May each year. The 12 months to May 2018 averaged 0.82 °C above the 1951-1980 mean, which was 0.19 °C cooler than the 12 months to May 2016.

This makes it the third hottest June to May 12 month period on record after 2016 and 2015.

Saturday, June 16, 2018

David Archibald tells lies about Australia's climate, at WUWT

Sou | 3:24 PM Go to the first of 8 comments. Add a comment
David Archibald is someone who often predicts the world is about to get very, very cold. He's not a denier, he's a disinformer. He tells lies. One of the many who Anthony Watts promotes on his climate conspiracy blog WUWT.

I couldn't let this one pass, because this time he was claiming it hasn't warmed in Australia in 40 years. He's wrong. It has.

Below is a chart showing the surface warming from data recorded and analysed by Australia's Bureau of Meteorology, one of the foremost climate and weather offices in the world. It includes a LOESS smooth (red line) and a linear trend line from 1979 to 2017.



Thursday, June 14, 2018

Climate science deniers take a dim view of reading science and heeding experts

Sou | 12:39 AM Go to the first of 11 comments. Add a comment
The other day (was it only yesterday) Anthony Watts predicted that newly-appointed Jim Bridenstine would soon lose his job as head of NASA (pictured right).

Anthony was relying on an article by James Delingpole on a competitor site of WUWT, Breitbart. James wrote scoffingly, quoting Mr Bridenstine:
I read a lot”?
What was Bridenstine thinking?
What indeed - reading for heaven's sake. Who in their right mind would read? Not James Delingpole, that's for sure.

Monday, June 11, 2018

Manipulating Tim Ball at WUWT

Sou | 8:28 PM Go to the first of 5 comments. Add a comment
Tim Ball is Anthony Watts' pet conspiracy theorist. He's an utter nutter of the first order. He was the first-named author of a book denying the greenhouse effect (pictured right).  Anthony Watts never mentions that, although he has a policy that "WUWT is a slayer free zone". Anthony only implements this policy on very rare occasions, and always exempts Tim Ball.

Today I'll just write about one thing, and it's not about Tim's main preoccupation (anti-semitic conspiracy theories). This time it's about manipulation.

Manipulation is a curious word. It sends shivers down the spine of every science denier yet they flock to blogs like WUWT where manipulation of the gullible is the only stock in trade.

Anthony Watts posted an article with the usual nonsense from Tim Ball (climate science is a hoax, a communist plot, a conspiracy for world domination by persons sometimes named, sometimes not). In it, Tim opened with this sentence:
The Intergovernmental Panel on Climate Change (IPCC) and the people who formulated the structure that directed their research, constantly manipulated the data and the methods to predetermine the results.

Thursday, June 7, 2018

Two uncomplicated tips for Judith Curry's dilemma

Sou | 8:05 AM Go to the first of 12 comments. Add a comment
Judith Curry, who used to be a scientist and is now science denier, has asked a question: "How can the fundamental disagreement about the causes of climate change be most effectively communicated?"

She claims there is a fundamental disagreement on what is causing the climate to change. She doesn't cite any people who disagree with the fact that increasing atmospheric CO2 is causing global warming. She just asserts that there is "fundamental disagreement".

Nor does she explain what she thinks the fundamental disagreement is over, although she hints in a mockup of a slide that she thinks something other than the massive increase in CO2 is causing global warming. What that is only she knows, or doesn't. If she does she isn't saying, which is typical of deniers.

Thursday, May 31, 2018

Lightning fire confusion at WUWT

Sou | 11:04 PM Go to the first of 5 comments. Add a comment
Bushfire Mount Beauty 11 December 2006
It would be nice to think that wrong headlines like the one below are the reason for the decline in WUWT readership. Thing is, headlines that don't reflect a copy and pasted article are par for the course at WUWT. The headline is: "Claim: Global warming to make more lightning caused fires, but only in the Northern Hemisphere."

Anthony Watts got his north and south mixed up. The paper is about an increase in lightning caused fires in the southern hemisphere. So far, no-one at WUWT has noticed (archive here).

Notice, too, that Anthony continues his "claim" prefix. He does that with most of the press releases he copies, showing that he doesn't "believe" science and wants his readers to think that science is nothing but a hoax.

Are nefarious forces causing the public to cool on the idea of climate conspiracies?

Sou | 8:58 PM Go to the first of 20 comments. Add a comment
According to conspiracy blogger Anthony Watts, nefarious forces have been responsible for the slowdown in his blog traffic. He put up an article about how he reckons his blog has been "under attack by a variety of forces".  The short version is that he's got WordPress to transfer his anti-environment blog onto their cloud platform.

There's more conspiratorial paranoia, too. He wrote in part:
"In the short term this migration may mean some interruptions of service, in the long-term this should ensure that WUWT continues to reach audiences worldwide without interruption or interception by some of the nefarious forces that operate from the shadows trying to reduce the impact this website has. It will also toughen the site against attacks."
Just thought I'd let you know that this nefarious force will soon be on its way back from the shadows to play its small part in reducing the ruinous impact of climate science deniers on our precious world. (Other obligations have kept me away for longer than I expected.)

Tuesday, April 10, 2018

Anthony Watts is irate that Gavin Schmidt didn't call out a climate science denier!

Sou | 5:29 PM Go to the first of 14 comments. Add a comment
This is rich. A climate science denier on Twitter wrote a sarcastic tweet, and Anthony Watts is irate.

No he's not irate that the denier was sarcastic. What he's irate about is that Gavin Schmidt, the Director of GISS at NASA didn't call it out.

Anthony Watts wrote a whole article on his blog at WUWT complaining that Dr Gavin Schmidt didn't repudiate this person. Here's the tweet in question (click the link to see it in context):


No reasonable person reading that tweet would take it at face value. It dings all sorts of alarm bells. Then again, whoever accused a "climate hoax" conspiracy theorist like Anthony Watts of being "reasonable"?

Monday, April 2, 2018

Right wing anti-intellectuals can't get into university - so implies the dimwits at WUWT

Sou | 12:15 PM Go to the first of 35 comments. Add a comment
aeroplaneLooking through comments to the latest article at WUWT, it's clear that the general view of Anthony Watts' fans think that science deniers are incapable of getting into academia. Every comment implies that a university job in whatever field, which entails going to conferences, is restricted to people who accept climate science. Deniers are incapable of getting a job at a university, according to WUWT-ers. At best, they are in such a tiny minority that they don't count.

This is a rather strange position for science deniers to take though it does make sense, in a weird way. WUWT fans are assuming people who deny science don't do PhDs or post-docs, let alone make a career for themselves as a lecturer and/or researcher. They assume that science deniers do not have the inclination (or the wherewithal) to do academic research.

If you want evidence, see for yourself. Eric Worrall has copied and pasted some of an article at Huffington Post, written by two academics: Nives DolÅ¡ak and Aseem Prakash. The article was suggesting ways that universities and academics could offset their air travel, though Eric didn't write about that. His focus was on the fact that academics fly across the country and around the world to conferences, to exchange ideas with their colleagues.

Sunday, March 25, 2018

The strange madhouse of climate science denial - defaming Einstein at WUWT

Sou | 7:48 AM Go to the first of 27 comments. Add a comment
Anthony Watts, a long-time denier blogger, is pushing the notion that Albert Einstein would likely have been a climate skeptic.

Really? Resorting to impugning the integrity of a long dead scientist to justify his anti-science propaganda?

Anthony is claiming that Einstein would have been a fake sceptic or worse, a science disinformer, a liar denier, like Anthony himself is. That's a big idea and one for which he offers no support. Oh he posted an article underneath his headline, which was written by some bloke called David Shapter, or was it Will Happer?

Thursday, February 15, 2018

Climate science denial dismissed - Judge finds Tim Ball too wacky to be believed

Sou | 9:52 AM Go to the first of 18 comments. Add a comment
Over at WUWT, Anthony Watts has gleefully announced to his climate conspiracy mob that a Canadian judge has dismissed a lawsuit against Tim Ball. What Anthony didn't (and probably won't) tell his readers, is that the judge dismissed the complaint because:
Simply put, a reasonably thoughtful and informed person who reads the Article is unlikely to place any stock in Dr. Ball’s views, including his views of Dr. Weaver as a supporter of conventional climate science.

Now we know that no-one who is a fan of WUWT is a "reasonably thoughtful" or "informed person". And we also know that about 99% of them won't bother reading any judgement, and most don't read DeSmogBlog (or HotWhopper) either. Still, I thought it might be useful to spread the word, thanks to Richard Littlemore - who wrote about this first.

If the argument put by the judge is extended, it means that he regards most fans of Anthony Watts' wattsupwiththat blog as unreasonable, lacking in thinking power, and distinctly uninformed. He also holds a large minority of the US population in contempt, the ones who still believe anything their authoritarian idols tell them to believe.

Another key quote was how the Judge found Tim Ball intended to harm then climate scientist Andrew Weaver:
The judge agreed, saying, first of all that Ball’s intent to injure was adequately established in the evidence:
These allegations are directed at Dr. Weaver’s professional competence and are clearly derogatory of him. Indeed, it is quite apparent that this was Dr. Ball’s intent.
That's why I think Andrew Weaver stands a chance if he chooses to appeal. Even though I agree with the judgement in its essence, it's also not unreasonable to argue that something like 30% of the US population might be "reasonably thoughtful" despite being wrong about climate science, and are instead merely "uninformed". (That's not the case for probably most WUWT commenters. The long term fans can only be considered as unscrupulous disinformers who deliberately spread lies, or are wilfully ignorant, because they've had ample time and means to find out the facts for themselves.)

Now will Anthony keep his promise and perhaps post the judgement (pdf) or not. Any bets?

By the way - I did predict that Tim Ball was trying for the insanity defense, back in April last year. He must be very pleased his efforts have come to this!

As an aside, sorry for being tardy in getting back to blogging. Other commitments mean articles will be a bit slow coming for a little while yet. Sorry about that. I shall return in full swing shortly.


Further reading


Is Tim Ball wanting to try the "insane" defense in his court cases, with the help of Anthony Watts? - HotWhopper article from April 2017

More about Tim Ball from HotWhopper

Wednesday, February 7, 2018

The spectacular failure of the 2007 climate "bet" by denier J. Scott Armstrong

Sou | 1:20 AM Go to the first of 20 comments. Add a comment
Today at WUWT there's a rambling, indecipherable article about some bet that a science denier called J. Scott Armstrong unsuccessfully tried to make with Al Gore way back in 2007. It's a tale of a failed denier prediction, and worse. Having failed so spectacularly, J. Scott Armstrong is doubling down and betting on a drop of up to 4.5 °C in global temperature over the next decade.

Armstrong was wanting to bet that there'd be no change in global average surface temperatures between 2008 and 2017. He figured, wrongly, that Al Gore would bet there would be warming. Al Gore didn't take the bet. Why would he deal with a nincompoop denier like J Scott Armstrong.

Armstrong's first draft of the bet was a bit weird. The essence of it was this:

Saturday, January 13, 2018

Anthony Watts gets over-excited by a meaningless weather (not climate) "award"

Sou | 2:39 PM Go to the first of 15 comments. Add a comment
For HotWhopper, not WUWT
This reminds me of Donald Trump, always wanting to magnify his magnificence and making a fool of himself in the process.

Anthony Watts is over the moon with excitement that he came top of the class in the weather blog category of some award. The "award" looks to be a way of getting clicks to a content reader/gatherer called Feedspot, which was set up a few years ago - back in 2013 from the look of things.

It's weather, not climate, Anthony!


Well, I've got news for Anthony Watts. He probably didn't know that Feedspot also has a top 40 global warming and climate change category. That's because WUWT isn't in the top 40. It didn't make the list, as of this writing. The top website in that category is SkepticalScience.com.

Thursday, January 11, 2018

When 97% becomes 99.6% - climate change in 2017

Sou | 6:37 AM Go to the first of 12 comments. Add a comment
Anthony Watts has kindly pointed out that the scientific consensus on climate change is changing. He wrote the very strange headline: "‘The 97% climate consensus’starts to crumble with 485 new papers in 2017 that question it". Apparently some drongo (who does this every year IIRC) has only managed to dig up 485 "papers" that he claims " in some way questioned the supposed consensus regarding the perils of human CO2 emissions or the efficacy of climate models to predict the future."

I expect that, as in past collections, many of findings of those 485 don't dispute climate change, and many probably support the fact that human activity is causing global warming, but I haven't bothered checking (because that's not the point of this little article).  What struck me was that 485 was a pretty small number given the vast number of peer-reviewed publications on climate change these days.

If you go to Google Scholar and search for the term "climate change" and select "2017-2017", you'll find there were "About 115,000 results". Now 485 is 0.4% of 115,000, so even if all those 485 papers disputed the greenhouse effect (which they don't), it would still mean that one could argue that 97% has become 99.6% :D

Now that even beats the 98.4% of WUWT-ers who deny straightforward science. Who'd have thought!

Thanks, Anthony Watts, Breitbart, Pierre Gosselin and Kenneth Richard.

Sunday, January 7, 2018

The latest conspiracy theory from WUWT science deniers - losing their grip on ice

Sou | 2:52 AM Go to the first of 3 comments. Add a comment
The latest conspiracy theory from science deniers at WUWT is that the National Snow and Ice Data Center (NSIDC) is up to something nefarious. (Seeing nefarious intent in the most innocuous actions is one of the hallmarks of conspiratorial thinking.)

All the fuss was about a new version of NSIDC's Sea Ice Index. It's gone from version 2 to version 3. In the latest version, monthly averages are calculated in a different way. The new version only affects monthly averages, not anything else. From the analysis report:
The Sea Ice Index has been updated to Version 3 (V3). The key update in V3 is a change in the method for calculating the numerical monthly averages of sea ice extent and sea ice area data values; that is, the data distributed in .csv and .xlsx format. This change impacts only the monthly data values in the Sea Ice Index time series and not monthly sea ice extent and concentration maps that accompany the data product, that is, the .png, .tif, and shapefile archives. Daily data are also not impacted, nor are any current conclusions drawn from the Sea Ice Index data set about the state of sea ice in either the Arctic or the Antarctic. This change is being made in response to questions raised by users of the product concerning how the monthly average ice extent and areas are calculated.

Friday, January 5, 2018

Getting rid of the spurious blips - another look at global sea surface temperatures

Sou | 3:34 PM Go to the first of 11 comments. Add a comment
Kevin Cowtan | Source: U York
Once again, Kevin Cowtan has brought his skills to climate science, working with Robert Rohde and Zeke Hausfather. They decided to explore those pesky ups and downs in the temperature record, which a lot of people (scientists mostly) have expressed concerns about. This new paper is largely addressing bucket bias in sea surface temperature and is very detailed. Taken with his other work on temperature records, this has to cement Kevin Cowtan's place among the "serious climate nerds" (h/t ykw!)


A hybrid check on sea surface temperature bias corrections


The authors analysed sea surface temperature, the main source of the temperature blips, from a new perspective. Their analysis can be seen mainly as a check of the bias corrections used in other sea surface temperature records. Instead of reanalysing data from ships and buoys, they compared weather stations on the coast and on islands with the measurements taken on ships when they passed close to the coast. They subjected this to further analysis and called the result a hybrid SST (sea surface temperature).



I can only imagine how much work this must have entailed. There are hints in the paper. Not only did they get the temperature records from land and nearby sea, they made adjustments in their analysis to compensate for the fact that with global warming, the land surface is warming faster than the sea surface, plus more.

They used their results to assess the bias correction that needs to be made when the sources for sea surface temperature changed, such as from buckets to engine intake, and to buoys (see below). The end result was a different check on sea surface temperatures and additional evidence that:
  • Some of the odd blips in the temperature records were not what actually happened - particularly the upward WWII blip and the drop down around 1910
  • The NOAA sea surface temperature record from 1997 onwards is probably closest to reality. On the other hand, the Cowtan17 analysis indicates ERSST v4 is too warm in the earliest years (1860 to 1900 or so) and too cool in the early 20th century (1910 to late 1930s).
  • Climate models reflect reality even more closely than previous records suggest. 
There's an excellent article on Kevin Cowtan's website which explains the research, and accompanying provisos. The paper and supporting information contain a lot more detail, including all the ifs and buts and maybes. Co-author Zeke Hausfather has a  Twitter thread about the paper, too.


Challenges in the historical record of sea surface temperature


The authors begin by pointing out that getting a record of sea surface temperature is more challenging in many ways than putting together land temperature records. The difficulty with sea surface temperature is that information sources change much more than those on land.

On the land, apart from getting as many records together as possible (thank you CRU and other early collectors, and more recently ISTI), the main issues to contend with are adjusting for changes in instrument design and location. Location changes can be identified from station records or inferred from abrupt changes in the record compared with neighbouring records. Technological change hasn't happened all that often in the past 150 years or so. The main ones include the introduction of the Stevenson screen way back, and the more recent shift to automatic weather stations with resistance probes replacing mercury thermometers.

On the sea, the problems include the different sources for temperature readings: buckets of differing materials being dipped into the sea, engine room intakes, sensors on the ships hull and, more recently, drifting buoys and satellites. Within all that, scientists have to account for things like changes in the height of ship decks, interruptions to the consistency of records caused by world wars (where the data source changed from predominately merchant ships to predominately naval vessels), and more. The marvel is that researchers have worked through all these difficulties and developed records of sea surface temperature going back many decades.


Questionable peaks and troughs in the SST records - WWII and all that


One period about which most scientists who've worked on the subject have had most issue with are the years of the second world war (WWII). Some data sets show a peak in temperature that has not been easily explained by weather or climate change phenomena. In addition, previous records show a drop in the temperature around 1910 that looks a bit odd. In this paper, the authors did not find the spike that exists in ERSST v5 and to a lesser extend in HadSST3. Neither did they find the drop in temperature in the early 1900s.

In the top chart below, the hybrid record is shown in blue. The different series are a bit hard to distinguish so you might want to click on the image to enlarge it.
Figure 1 | Comparison of the coastal hybrid temperature reconstruction (using all coastal stations and fitting the global mean of the coastal temperature differences only) to co-located data from HadSST3 and ERSSTv5 for the period 1850-2016. Spatial coverage is that of HadSST3 for all of the records, with coastal cells weighted by ocean fraction.The shaded region is the 95% confidence region for the HadSST3 anomalies including combined bias adjustment and measurement and sampling errors. The lower panel shows the adjustment applied to the raw data in the HadSST3 and coastal hybrid records. A comparison with the ERSSTv4 ensemble is shown in Figure S7. Source: Cowtan 17 Figure 12.

To help see the difference, the chart below compares the Cowtan17 hybrid record with NOAA's ERSST v4 record. As discussed, the two are very similar in the most recent decades, but differ much more in the period prior to the early 1940s.

Figure 2 | Comparison of coastal hybrid temperature reconstruction to the ERSSTv4 ensemble. The dotted line is the ensemble median, while the shaded region is the 95% range of the ERSSTv4 1000 member ensemble from Huang et al (2016). DOI: 10.1175/JCLI-D-15-0430.1 . Source: Cowtan17 supporting information Figure S7

The table below highlights further that the Cowtan17 analysis is closer to the NOAA data set for the period after WWII since 1997 than it is to the Hadley record (HadSST3). The trend of HadSST3 is lower than that found in Cowtan17 and ERSST v4.

Table 1: Trend in sea surface temperature since 1997. Source: Cowtan17 Supporting Information Table S2.


The analysis supports the CMIP5 models


Another thing the analysis suggests is that there is less of a difference between observations and the blended mean from CMIP5 model runs. This is shown in the chart below, from Kevin Cowtan's briefing paper, where the green line is the CMIP5 blended mean.
Figure 3 | Comparison of global temperature records based on either the UK Met Office sea surface temperature record (HadSST3), or our coastal hybrid record. The smoothed records are compared to the average of climate model simulations from the CMIP5 project. The lower panel shows the differences between each set of observations and the models. Source: Kevin Cowtan's blog article.


Constraints and provisos


The authors of Cowtan17 show a lot of restraint and go into quite a bit of discussion of uncertainties and provisos. They present their findings not as the be all and end all of temperature reconstruction, but as a suggestion of where to investigate further. Kevin Cowtan wrote in his briefing:
However we do not necessarily trust our new record, because of the assumptions we had to make in constructing it. The most important result of our work may therefore be to identify places where extra attention should be given to addressing problems in the existing sea surface temperature records. A secondary result is that caution is required when trying to draw conclusions about any differences between the models and the observations, whether it be to identify internal cycles of the climate system or problems in the models, because the differences that we do see are mostly within the range of uncertainty of the observations.

Just the same, this paper has a lot of merit, looks at the data differently, and shows that the spurious peaks and troughs from years gone by may indeed be out of whack. It also supports the records in recent times, which seems to me to add weight to their findings.


What deniers are saying about Cowtan17


Nothing. At least nothing at WUWT or anywhere else that I've seen. Either they all missed the paper because it came out in the holidays, or they haven't figured out what to say about it.


References and further reading


Cowtan, K., Robert Rohde, and Zeke Hausfather. "Evaluating biases in Sea Surface Temperature records using coastal weather stations." Quarterly Journal of the Royal Meteorological Society (2017). DOI: 10.1002/qj.3235 (pdf here)