A post by Judith Curry discusses the “Early 20th Century Warming,” i.e. the rise in global mean temperature during the early 20th century. True to form, Curry can’t get past the first sentence without telling the kind of whopper which shows how little she understands about the topic she has chosen:
A careful look at the early 20th century global warming, which is almost as large as the warming since 1950.
Bullshit. I’ve heard this bullshit before.
Deniers have made the claim for at least a decade now, in fact they have even faked graphs to make the claim. So what the hell is Judith Curry doing saying so? How much did the globe warm in the “early 20th century,” and how much “since 1950?” Does Judith Curry even know?
I doubt it.
Let’s take global temperature data, and fit a smooth curve to the data since 1900. That way we can reduce the amount of random fluctuation, giving a closer look at the trend, what global warming is really up to. Then let’s estimate “early 20th century warming” as the total range covered by the smooth estimate between 1900 and 1950. Next, we’ll take the difference between the 2018 value and the 1950 value to estimate the warming “since 1950.” We’ll start with the data from NASA:
The early warming amounted to 0.31°C, but since 1950 it has risen 0.86°C, which is 2.8 times as much. Do you really think it qualifies as “almost as large” when the recent warming is almost three times as big?
NOAA data say that recent warming is only 2.56 times as large as early warming:
For the HadCRUT4 data, recent warming is a “mere” 1.85 times as large as the early 20th century warming!
I just got a message from Peter Dinklage, saying that he’s “almost as large” as I am. I informed him that I had sent a similar message to Kareem Abdul-Jabbar.
The data from Cowtan & Way have recent warming 2.04 times as big as early warming:
The data from Berkeley Earth have the ratio at 2.05:
Curry does at one point admit that for data covering land areas, the warming since 1950 is “substantially” more than during the early 20th century. That’s kind of hard not to admit, when the recent warming is over three times as large as early warming:
Convincing anyone that it’s “almost as large” as something three times as big … that’s a hard sell, even to gullible climate deniers.
Why Curry is invested in this dumb idea, is revealed by her second sentence:
Until we can explain the early 20th century warming, I have little confidence IPCC and NCA4 attribution statements regarding the cause of the recent warming.
Here is my opinion.
Judith Curry doesn’t want anyone to believe that modern warming is due to man-made greenhouse gases (or anything else man-made). Therefore she uses the early 20th century warming, about which we know but little, to make the case that “if we can’t understand then, how can we understand now?” To get this case to work, she has to portray the early 20th century warming as being comparable to modern warming, so that’s what she says (her exact words: “almost as large”), with no evidence to back it up. God forbid she should actually have to calculate some numbers! It’s not her strong suit.
Seems to me, this is just like saying “Look! There was a spike in lung cancer deaths in this region, before the introduction of tobacco. Until we can explain the early lung cancer outburst, I have little confidence in WHO and CDC attribution statements regarding the cause of the recent elevated lung cancer rates.
Yes, folks. That’s really what Curry and her ilk are doing. They do it a lot. There’s something we don’t understand, so we don’t understand anything! If they have to exaggerate to make their case look plausible, they will. At least, that’s my opinion.
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Tamino: “Judith Curry doesn’t want anyone to believe that modern warming is due to man-made greenhouse gases (or anything else man-made). ”
My take: She doesn’t want to lose her cushy scam as the go-to climate scientist for the denialati. She doesn’t want to lose the adulation or her adoring–and deluded–fanbase. She doesn’t want to admit that she’s just a mediocre scientist who doesn’t even understand her own specialty.
Hello — posting here because it looks like comments aren’t open on your Kremsmünster post any longer. That was a terrific post. Thank you very much. I wanted to let you know that I fully replicated it and added a couple of simple forecasts, and posted the R code to do so on my blog: http://rethinking.rbind.io/2019/01/21/140-years/.
this is an attempt to make it reproducible for anyone willing to run to code. It would be very simple to change the code now to run on _any_ station on the ECA&D dataset. thanks again and comments welcome.
[Response: What a nice thing to do. Thanks.]
Just tweeted to Curry:
“…almost as large”? From critique by Tamino (https://tamino.wordpress.com/2019/01/23/hot-and-cold-curry/): “I just got a message from Peter Dinklage, saying that he’s “almost as large” as I am. I informed him that I had sent a similar message to Kareem Abdul-Jabbar.”
Please do not insult cattle manure. Useful fertilizer out on the fields.
For those inclined to be fooled by the noise, it’s easy to arrive at Dr. Curry’s conclusion. It’s 0.6-0.7 c from the low point in the early 1900s to the peak at about 1940. The increase from that peak to the 2016 maximum is just a little bit more. This tomfoolery can be observed in each of the datasets except for Berkeley Land-only.
Dr. Judith Curry lacks confidence in the work of climate scientists?
– And is willing to say so on a blog?
What ever will we do now?
Until I can explain Dr. Judith Curry’s continued descent into scientific irrelevance, I have little confidence in her very questionable opinions on IPCC and NCA4 attribution statements regarding the cause of the recent warming.
See what I did there?
Well.. If you ignore anything past 2000 (’cause we’re in a pause anyway, right?) and you compare only early 20th century warming to late 20th century warming, then subtracting two times the decadal trend of about +0.2C would get you close to comparable warming for the two periods for at least one of the datasets. If I were her that’s what I’d have done, rather than say “since 1950”.
I’m more concerned about your statement that: “…the early 20th century warming, about which we know but little..”
My understanding is that GCMs with natural forcing reproduce the observed warming before 1950 reasonably well – there’s a mismatch on the immediate response to Krakatoa in 1880-something – and this suggests that most of the warming was due to changes in volcanic activity and solar output.
What am I missing?
Did you hit up Dinklage for any GoT spoilers/leaks?
Because Winter is clearly not coming here…..
Always makes me wonder: how many decades (4 so far) of warming at 1.5 or 2 degrees per century will it take to stop obsessing about the one (1) decade when that happened in the early 20th century (1930s compared to 1940s) and the couple previous ones that warmed at a distinctly lesser rate. (data from GISSTEMP) It’s a perfectly valid scientific inquiry, but for a layperson or Congressperson trying to decide on policy, it’s a tiny footnote.
Another persuasive analysis of reality: thank you. But is there something else to be said about the rate of warning in the two periods? Is the rate of increase 1980-to date the same as 1920-1940? Does your correlation with ENSO, aerosols, solar irradiance, and CO2 explain both the similar rate, and the decline 1940-1980?
Can’t help with the corrected data, but for GISTEMP the rate of increase is pretty close: ~0.16 C/decade for 1920-1945 (I extended your period a bit for fuller cherry flavor) and ~0.17 C/decade for 1980-present. For good measure, I threw in the mid-century period, which shows a weaker warming trend of 0.03 C/decade.
But if we’re going to join in playing the cherry-picking game, let’s compare cherries to cherries: http://woodfortrees.org/plot/gistemp/from:1920/to:1945/plot/gistemp/from:1993/to:2018/plot/gistemp/from:1920/to:1945/trend/plot/gistemp/from:1993/to:2018/trend/plot/gistemp/from:1945/to:1993/plot/gistemp/from:1945/to:1993/trend
The trend for the 25-year period 1920-45 is 0.160 ±0.073 °C/decade (2σ) (https://www.skepticalscience.com/trend.php). For 1993-2018 it’s 0.209 ±0.075 °C/decade (2σ).
Might as well–there’s no turning them into apples.