UAH Global Temperature Update for January 2021: +0.12 deg. C (new base period)

From Dr. Roy Spencer’s blog

February 2nd, 2021 by Roy W. Spencer, Ph. D.

The Version 6.0 global average lower tropospheric temperature (LT) anomaly for January, 2021 was +0.12 deg. C, down a little from the December, 2020 value of +0.15 deg. C.  NOTE: We have changed the 30-year averaging period from which we compute anomalies to 1991-2020, from the old period 1981-2010. This change does not affect the temperature trends.

The linear warming trend since January, 1979 remains at +0.14 C/decade (+0.12 C/decade over the global-averaged oceans, and +0.18 C/decade over global-averaged land).

Various regional LT departures from the 30-year (1991-2020) average for the last 13 months are:

YEAR MO GLOBE NHEM. SHEM. TROPIC USA48 ARCTIC AUST 
2020 01 0.42 0.44 0.41 0.52 0.57 -0.22 0.41
2020 02 0.59 0.74 0.45 0.63 0.17 -0.27 0.20
2020 03 0.35 0.42 0.28 0.53 0.81 -0.96 -0.04
2020 04 0.26 0.26 0.25 0.35 -0.70 0.63 0.78
2020 05 0.42 0.43 0.41 0.53 0.07 0.83 -0.20
2020 06 0.30 0.29 0.30 0.31 0.26 0.54 0.97
2020 07 0.31 0.31 0.31 0.28 0.44 0.26 0.26
2020 08 0.30 0.34 0.26 0.45 0.35 0.30 0.25
2020 09 0.40 0.41 0.39 0.29 0.69 0.24 0.64
2020 10 0.38 0.53 0.22 0.24 0.86 0.94 -0.01
2020 11 0.40 0.52 0.27 0.17 1.45 1.09 1.28
2020 12 0.15 0.08 0.22 -0.07 0.29 0.43 0.13
2021 01 0.12 0.34 -0.09 -0.08 0.36 0.49 -0.52

The full UAH Global Temperature Report, along with the LT global gridpoint anomaly image for January, 2021 should be available within the next few days here.

The global and regional monthly anomalies for the various atmospheric layers we monitor should be available in the next few days at the following locations:

Lower Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tlt/uahncdc_lt_6.0.txt
Mid-Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tmt/uahncdc_mt_6.0.txt
Tropopause: http://vortex.nsstc.uah.edu/data/msu/v6.0/ttp/uahncdc_tp_6.0.txt
Lower Stratosphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tls/uahncdc_ls_6.0.txt

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John Tillman
February 2, 2021 6:10 pm

OMG! Average for a century of 1.4 degree C. We’re all going to die!

After living on average 70 to 80 years.

Tom
Reply to  John Tillman
February 2, 2021 8:30 pm

Reminds me of The Onion bit – “Tense India-Pakistan standoff enters 11,852nd day”
News Anchor: “How are people coping with the situation there?”
On-the-scene Reporter: “Mostly by growing old and dying.”

The same *horrific* end that awaits us due to climate change. We will mostly live until a ripe old age (thanks to the economic prosperity brought by fossil fuels) and then die.

Andy Pattullo
Reply to  Tom
February 4, 2021 8:38 am

If we don’t stop climate change in the next 45 minutes, seven and a half billion of us will die before the end of the century. I’m not worried – I’ll be gone by mid century.

February 2, 2021 6:10 pm

GROUNDHOG DAY 2021: USA – PUNXSUTAWNEY PHIL PREDICTS SIX MORE WEEKS OF WINTER
GROUNDHOG DAY 2021: CANADA – WIARTON WILLIE AND SHUBENACADIE SAM CALL EARLY SPRING
 
OK – we have a yet another cross-border crisis – this one is about Groundhog Day.
Normally, I’d go with the Canadian prediction over the American one, because Canadians, like, y’know, we know Winter!
But in this case, I’ll make you Yanks a deal:
I’ll go with Punxsutawney Phil and six more weeks of Winter, but you gotta remove energy-idiot Biden’s veto on the Keystone XL pipeline;
also, we’ll agree on a trade – you take Trudeau and we’ll take Trump.
Fair Warning: If you take Trudeau, the weighted average IQ of the entire USA will drop by several points.

David Long
Reply to  ALLAN MACRAE
February 2, 2021 9:43 pm

If we take Trudeau you’ve got to take Kamala Harris, Cuomo and an Antifa to be named later.

Streetcred
Reply to  David Long
February 2, 2021 10:05 pm

Might throw in the Aussie PM whilst we’re about it. ScoMo is becoming a liability.

Reply to  David Long
February 2, 2021 10:17 pm

David – no deal! We get Harris, Cuomo and some Antifa thug?
That trade would make both countries a lot stupider!

Seriously, here’s a 2018 proposed deal that makes sense for both countries. You’d also have to cut a sensible deal on cross-border energy. First, put someone in charge who is not an energy idiot.

https://wattsupwiththat.com/2018/07/15/claim-climate-change-will-cause-a-global-corn-crop-failure/#comment-2405467

Let me double-down, Donald Trump. Sooner or later the Ogalalla Aquifer is going to be excessively depleted and the greatest grain-growing region in the world, the US Midwest, is going to suffer greatly reduced agricultural production.

Canada has excess water (plenty of it). It is part of OUR national far-left religion that WE WILL SHIP NO WATER TO THE USA.

But let’s be sensible – to Hell with the leftists – they are scoundrels and/or imbeciles anyway.

If you agree to use Canadian water wisely – to recharge the Ogalalla aquifer, cease foolish and wasteful biofuels production, and use the food to feed the world’s hungry, we can do a deal.

What do you say? Let’s do lunch! 🙂

Mickey Reno
Reply to  ALLAN MACRAE
February 3, 2021 1:44 am

If Canada refuses to ship water to the US, we’ll pump it out of OUR half of the Great Lakes. HAH! What do you say to that, Trudeau? Then, later when your continental glaciers begin bulldozing Detroit and Cleveland and Buffalo, we’ll sue Canada in Washington D.C. district court, and then, based on the Michael Mann, Mark Steyn lawsuit paradigm, time will stop advancing altogether, and we’ll all live eternal, immortal lives indistinguishable from Covid lockdown. I hope I get my Joe Biden Covid relief check before that happens, as I’ve always wanted a Lamborghini and after time stops, the Lamborghini will go the same speed as every other car, zero mph.

Last edited 7 months ago by Mickey Reno
Gerald Machnee
Reply to  David Long
February 3, 2021 7:43 am

Maybe add Hunter and we get the Russian and Chinese cash.

Tom Abbott
Reply to  Gerald Machnee
February 4, 2021 6:20 am

Less ten percent for the “Big Guy”.

Gerald Machnee
Reply to  ALLAN MACRAE
February 3, 2021 7:42 am

I found the Canadian groundhogs sincere in their actions.
However, watching Phil on TV in the morning made me suspicious. The declared that he saw his shadow, but I saw snowflakes falling as they spoke. Sounds like they were speaking one of Biden’s “truths”.

Reply to  Gerald Machnee
February 3, 2021 9:00 am

Phil is a Democ-rat.

Clyde Spencer
Reply to  ALLAN MACRAE
February 3, 2021 9:55 am

Shouldn’t that be “Demonic-rat?”

Reply to  Gerald Machnee
February 3, 2021 2:03 pm

GROUNDHOG DAY 2021: USA – PUNXSUTAWNEY PHIL PREDICTS SIX MORE WEEKS OF WINTER
GROUNDHOG DAY 2021: CANADA – WIARTON
WILLIE AND SHUBENACADIE SAM CALL EARLY SPRING
 
ADDENDUM: QUEBEC’S FRED LA MARMOTTE FORECASTS AN EARLY SPRING!
https://Montrealgazette.Com/News/Quebec/Live-Groundhog-Day-With-Quebecs-Fred-La-Marmotte/
 
In a rare display of bicultural and binational unity, Quebec’s Fred La Marmotte also predicts an early spring!
 
Quebec Premier Jean-Guy Crosseur was moved, and conceded – “OK den, we will allow da h’oil pipeline from h’Alberta to da h’Atlantique – no more maudit paying twice as much for da dirty foreign h’oil!”
 
So It’s Canadian rodents Wiarton Willie, Shubenacadie Sam And Fred La Marmotte All Calling For An Early Spring!
 
Punxsutawney Phil objected strenuously, citing Canadian bullying and piling on, and retreated to his ‘safe space’ in his burrow. Phil’s parting words were “Youse can take your Keystone XL pipeline and shove it!”
Phil’s a Democ-rat!

Fred la Marmotte was adamant, saying: “Jsuis completement ‘fed-up’ avec cet maudit l’hiver trop froide, tabarnak de l’esti!

Last edited 7 months ago by ALLAN MACRAE
Tom Abbott
Reply to  Gerald Machnee
February 4, 2021 6:22 am

“I found the Canadian groundhogs sincere in their actions.”

I didn’t even know they had weather-forecasting animals in Canada. That was news to me. 🙂

BCBill
Reply to  Gerald Machnee
February 4, 2021 8:36 am

That’s Novaya Pravda, the new truth. Much like the old Pravda but includes even more ridiculous truths like multiple genders. The various BCs specialise in Novaya Pravda (ABC, BBC, CBC)

BCBill
Reply to  ALLAN MACRAE
February 4, 2021 8:43 am

Six more weeks of winter in the US is climatically the same as six weeks of spring in Canada.

Devils_Tower
February 2, 2021 6:10 pm

Did they adjust Dec down from .27???

Scissor
Reply to  Devils_Tower
February 2, 2021 6:19 pm

Probably due to the new base period.

John Tillman
Reply to  Devils_Tower
February 2, 2021 6:20 pm

The new base period will make it easier to go negative on the anomalies. But it’s basically as meaningless as the whole global average temperature anomaly scam.

fred250
Reply to  Devils_Tower
February 2, 2021 7:05 pm

If you read Roy’s comments on the UAH page, …

…. Its actually a drop of about 0.03ºC from December.

Last edited 7 months ago by fred250
Patrick B
Reply to  fred250
February 3, 2021 4:22 pm

Right – because we can measure “earth’s temperature “ to hundredths of a degree.

Richard M
February 2, 2021 7:48 pm

The UAH data tends to follow the global SST data with a lag of 2-3 months. If that holds we should see a drop of about .1 C in February. Since this is in the error range that means it could it could be as much as .2 C (or zero)

https://woodfortrees.org/plot/uah6/from:1979/to/plot/uah6/from:1979/to/trend/plot/hadsst3gl/from:1979/to/offset:-0.2/plot/hadsst3gl/from:1979/to/offset:-0.2/trend

Keep an eye on the SSTs. They’ve been falling fast but it appears they could level off soon.

Bob Hunter
Reply to  Richard M
February 3, 2021 10:30 am

What about the AMO? Don’t many believe the Atlantic SST will continue to drop

Richard M
Reply to  Bob Hunter
February 3, 2021 7:09 pm

There are internal cycles of ups and downs within the positive and negative phases of the AMO so it is tough to say exactly when the AMO will move into its negative phase. It could still be 5+ years away or it could be next year.

The problem with the AMO is we simply don’t know what drives it while we do know other factors can influence the values of the index.

I think the PDO is more likely to go negative first.

James Schrumpf
February 2, 2021 7:50 pm

If there’s now a good 60-year baseline available, it should all be used. Why isn’t it?

Rory Forbes
Reply to  James Schrumpf
February 2, 2021 8:31 pm

Because they rely on the public not knowing the difference between weather and climate. “Come on man”, you don’t think this has anything to do with climate do you?

With a 60 year base line none of their claims are true.

fred250
Reply to  Rory Forbes
February 2, 2021 9:00 pm

Yep, they need to get to a baseline that includes a whole period of the AMO cycle at least.

1979 was the bottom of that cycle, we are now coasting along the top…..

…. so course its warmer now.

That is what cycles do.

TallDave
Reply to  James Schrumpf
February 3, 2021 7:07 am

all baselines are arbitrary

ugh just show the ACTUAL FREAKING TEMPERATURE

so ridiculous

menace
Reply to  TallDave
February 3, 2021 2:39 pm

Let’s suppose that the average temps in last 30 years was 28.2 C.

A graph of that would look identical to the anomalies graph except now on y-axis 0.0 C will be replaced by 28.2 C, 0.1 C by 28.3 C, -0.1 C by 28.1 C, etc.

But does that chart give you any better or worse info than the anomaly chart?

The trends (changes in temps versus time) are just as evident on an anomaly graph as on absolute graph. After all if the interest is “how much has it been warming recently” then knowing the average temp baseline used for the anomaly is really not important, as long as all the data is with respect to the same baseline average.

With an anomaly graph, it is immediately obvious if a given data point is above or below the baseline. That is not quite so obvious on an absolute chart. In fact the first thing you are going to ask on seeing an absolute chart is “But what was the average temperature?” With the anomaly chart the baseline average is inherent in the zero value.

But I do wish when they show an anomaly chart that they always state the baseline temperature average, just for full disclosure.

Tim Gorman
Reply to  menace
February 3, 2021 3:59 pm

Uh, the trends are not equal. A change from 28.2 to 28.3 is a 0.1/28.2 percent change, a 0.4% change. A change of 0.1 from a base temp of 0.1 is a 100% change.

Two entirely different slopes on the trend lines. One indistinguishable from zero, the other equal to one. One a horizontal line, the other a 45deg angle.

The issue is the CLIMATE. The anomaly tells you absolutely nothing about the climate. Only the absolute temperature can do that. If you tell your neighbor that the climate is going up every year at a 45deg angle as the anomaly shows and then tell him that the temp will change from 28C to 28.1C which is going to cause him the most heartache? Which will allow him to actually plan for what is going to happen?

Bindidon
Reply to  James Schrumpf
February 7, 2021 4:20 pm

James Schrumpf

It’s a bit late to answer, this thread has reached 0 degree of interest in between.

I recall some posts where you presented results of your evaluation of GHCN daily using your Oracle experience.

So my question: why didn’t you yourself try to show us how it would look like?

Yesterday I started for other reasons a generation of anomalies for GHCN daily, based on about 2500 stations worldwide (all with at least 105 years activity), one wrt the mean of 1981-2010, one wrt the mean of 1951-2010.

1 The anomalies raw as generated:

https://drive.google.com/file/d/1IH1m1unvpo8Cu4TKq5GE5lE2AIskRpKP/view

2 The anomalies, with those for 1951-2010 rebaselined wrt 1981-2010:

https://drive.google.com/file/d/1ySyba6Zq9_wMDnJkwPJTtZjDrfCcJ6Gs/view

Trends for 1880-2020 and 1979-2020 are identical for both anomaly series:
0.12 resp. 0.25 C / decade.

As you can see, it doesn’t matter whether you have a 30 year or a 60 year period for your baseline and anomaly construction.

Rgds
J.-P. D.

Rory Forbes
February 2, 2021 8:36 pm

I don’t give a damn what they say. A 30 year period for determining “climate” is no more valid than the belief that this planet has a measurable climate. It’s all just nonsense.

Mike
Reply to  Rory Forbes
February 2, 2021 11:26 pm

Agreed. The 30 year period was decided upon because that’s probably about as far as their imagination/attention span extends. Nonsense to be sure.

D. J. Hawkins
Reply to  Mike
February 3, 2021 5:46 am

Don’t blame the current crop of climate almost-scientists. The climate interval was a product of the early 20th century (1901, to be exact), long before it became profitable, er, fashionable, whatever, to scare children with claims of imminent climate doom.

Mike
Reply to  D. J. Hawkins
February 3, 2021 5:28 pm

Doesn’t make it any less ridiculous.

John F Hultquist
Reply to  Rory Forbes
February 3, 2021 2:39 pm

Look up the history of “Climate Normals.”
The National Weather Service (USA) has an entry.
Key words include World Meteorological Organization (WMO), the year 1935, and Warsaw.Of course you could search WUWT for one of my annual comments on this topic.

Paul Johnson
February 2, 2021 8:46 pm

I understand that the satellite data should be considered more accurate than station observations because the latter increasingly suffer from poor siting and encroaching urbanization. Does the satellite methodology account for the effects of GLOBAL urbanization or is that effect too small to matter? Over decades, expanding urban heat islands could distort the global average even if rural areas are unchanged.

fred250
Reply to  Paul Johnson
February 2, 2021 9:07 pm

“Does the satellite methodology account for the effects of GLOBAL urbanization or is that effect too small to matter?”

.

Almost certainly too small to matter

Here is a “urban areas of USA” map to give you a hint..

and 70% of the world is oceans anyway, plus VAST areas on uninhabited areas on land
.

comment image

Last edited 7 months ago by fred250
Tim Gorman
Reply to  Paul Johnson
February 3, 2021 5:16 am

While I trust the satellite record more than the surface record I still have an issue with what it means. The satellite basically takes one reading per day at each location per day. I’m just not convinced that this really tells us anything about the state of the globe. It’s like taking one measurement per day outside your house. Pick a time. Will that one temperature tell you if the current weather conditions are cool (spring or fall) or warm (summer) or cold (winter)? Since climate is an integral of the entire temperature profile (i.e. the weather conditions over time) what does just one measurement actually tell you?

Nick schroeder
Reply to  Tim Gorman
February 3, 2021 4:40 pm

The satellites are “tweaked” to match the surface. That’s obvious in SURFRAD and USCRN data sets.

Jim Gorman
Reply to  Tim Gorman
February 4, 2021 4:15 pm

The satellite measures something different from the land based stations and different from ocean based ARGO devices. I am not sure it is useful to even try and compare the absolute or anomaly temps directly. Even the trends could be different which complicates comparing them to each other.

RickWill
February 2, 2021 8:54 pm

I extracted the linked data from the UAH anomaly for the Nino34 region:
http://climexp.knmi.nl/data/itlt_60_120-170E_-5-5N_n_2015:2020.png

According to this, the Pacific is just coming out of the El Nino phase.

This chart below is taken from WUWT ENSO page:
comment image
It indicates the Pacific has been in La Nina phase for about 6 months.

It is rare that I back the BoM but the chart indicating the Pacific is deep into a La Nina phase is confirmed by my observations of the weather on the east coast of Australia.

I know UAH has no relevance to the surface temperature but I expect it would be without the bias it appears to have.

fred250
Reply to  RickWill
February 2, 2021 9:09 pm

“I know UAH has no relevance to the surface temperature”

.

Actually, since the trends in UAH USA48 and USCRN are very close to identical…

….. this VALIDATES UAH as a proxy for REAL surface temperatures.

RickWill
Reply to  fred250
February 2, 2021 10:18 pm

No it doesn’t. When it matches what the moored buoys achieve – zero trend in the satellite era, we can be confident it bears some relationship with surface temperature.

UAH clearly has a bias that needs correcting; again. Desperately in need of Version 7.

Temp_Nino34.png
fred250
Reply to  RickWill
February 2, 2021 11:44 pm

What you don’t seem to have caught onto is the fact that the max 30ºC regulated area, (which I agree with completely) can expand and contract a bit, thus causing the average in the tropical region to move up and down a bit.

Apart from the recent El Nino, UAH Tropic Oceans actually has very little trend and covers a much bigger region than the ENSO 3.4 region..

comment image

RickWill
Reply to  fred250
February 3, 2021 12:27 am

There is a significant trend in that chart; do the analysis and you will see the obvious.

My link above for UAH is reposted here as an image. It only covers the Nino34 region for a similar period to the BoM index. It is generally viewed that the region temperature needs to be 0.5C below the average for onset of El Nino. The UAH data for the region is still above the average. It is indicating that the Pacific is in perpetual El Nino, which it clearly isn’t.

Sure the warm pools move around from year to year bu there is ZERO trend in the tropical Pacific over the last 4 decades if the data from moored buoys is used. I place much more faith in the temperature record from moored buoys with transducers 1m below the surface than some derived number indicative of temptation extracted from energy emitted high in the atmosphere.

Screen Shot 2021-02-03 at 7.19.42 pm.png
fred250
Reply to  RickWill
February 3, 2021 1:45 am

Trend only exists because of the troughs in 1986 and 1989.

UAH Tropic Ocean is an anomaly, not linked to ENSO values.

It also deals with a much wider and larger area than ENSO data.

Last edited 7 months ago by fred250
Tim Gorman
Reply to  fred250
February 3, 2021 5:20 am

The trend also only exists because of the peaks in 1998, 2003-2007,and 2011.

The trend is from *all* of the values.

February 2, 2021 9:37 pm

I wonder why UAH does not pick up that the warming trend changes by latitude. See

https://breadonthewater.co.za/2021/01/26/am-i-a-climate-denier-denialist/

Last edited 7 months ago by HenryP
Tim Gorman
Reply to  HenryP
February 3, 2021 5:36 am

The data should be there. Is it just because no one has looked at it or does it not show that warming is latitude dependent?

Reply to  Tim Gorman
February 3, 2021 6:00 am

I am worried that what UAH measures up there is not what happens on the ground?

TallDave
Reply to  HenryP
February 3, 2021 7:11 am

only a satellite can actually see any significant portion of the ground

far more measurements can be taken

this is why when they launched the satellites, they were supposed to obsolete the surface stations

instead we discovered through the magic of adjustments that the past was colder than we thought

Last edited 7 months ago by TallDave
Clyde Spencer
Reply to  Tim Gorman
February 3, 2021 10:05 am

Latitude is certainly important because of insolation, but elevation, proximity to the ocean, direction of prevailing winds, and whether a region is on the windward or leeward side of mountains influence the climate.

Reply to  Clyde Spencer
February 4, 2021 7:56 am

1) Antarctica: -0.002K/jaar (Martijn)
2) Zuidelijk halfdrond: +0.002K/jaar (Henry, 2015))
3) Noordelijk half rond: +0.023K/jaar (Henry, 2015)
4) Het noordelijke pool gebied: (ik haal aan van hetzelfde report dat Martijn eerder aanhaalde)
The trend in estimated Arctic zone (60N-90N) temperature anomalies since 1979 is +0.00426C per month, +0.0511C per year
0.0511K/jaar dus, in het noord pool gebied.

Make up your mind? (click on my name)

Reply to  HenryP
February 4, 2021 8:01 am

I am not sure why the report on warming by latitude did not work/
try again clicking on my name

billtoo
February 3, 2021 12:56 am

keep in mind that feb 2019 USA48 came in at -.02 ( -.14 after the baseline change) despite over half of that area having one of the coldest februaries on record. Can’t wait to see what USA48 for 2021 does.

angech
Reply to  billtoo
February 3, 2021 2:43 am

 Climate Driver Update
Climate drivers in the Pacific, Indian and Southern oceans and the Tropics
2 February 2021
 The 2020–21 La Niña has likely passed its peak, with all of the international climate models surveyed by the Bureau anticipating NINO3.4
will return to borderline or neutral values by mid-autumn.
Fascinating.
The graph shows 7, count them, Climate models.
BoM,CanSIPS,ECMWF,JMA,METEO,NOAA,UKMO.
A change from the 19/1/2021 Climate Driver Update which featured 8 international climate models.
Missing?
Only NASA.
Why? Surely not because NASA correctly predicted the moderate La Nina and had the temerity to predict
 that it would keep going for at least 4 months
The opposite to BOM.
The sea surface temperature anomaly was predicted to go to -2.4 C for February, 2.6 C for March and 2.4 for April.
I am at a loss to fathom why they would drop the most highly respected data set, NASA after relying on it for years.
Perhaps someone could use the wayback machine on it.
I certainly feel they need to offer an explanation even if it is only a technical error.
It does seem a rather crude attempt to not publish data that disagrees with theirs.

*[For Moderator]

Good to see the new 30 year baseline.
It will make the current temperature increase look small and make potential future drops look massive.
An added feature Dr Spencer might comment on is the apparent drop to a negative month in late 2018?
Already working!

rbabcock
Reply to  angech
February 3, 2021 9:36 am

BOM (Australia) shows no warm water at depth below the La Niña east of 180 as of Jan 21, 2021.

BOM.jpg
angech
Reply to  rbabcock
February 10, 2021 6:43 pm

SURPRISED WHY NO ONE IS PAYING ANY ATTENTION TO THIS.

Sean O'Connor
February 3, 2021 2:38 am

Why isn’t a baseline of 1979-2020 used? Why start at 1991? There’ll just be accusations that the baseline is being cherry picked to make the anomaly seem less.

Dan M
Reply to  Sean O'Connor
February 3, 2021 8:22 am

Multiple people, including myself, have made the same comment on Dr. Spencer’s blog. When you’ve got the data for 40 years, why keep the 30 year time period for the baseline, just shifting it to the last 30 years? If 1980-2010 is used as a baseline (as it was for Dec, 2020), the anomaly would have been .24C. Using 1990-2020, it is .12C. Using the full 40 years roughly splits the difference at .18C. This example perfectly illustrates the issue of how sliding a 30 year window over the data allows one to cherry pick the data for your own purposes. We are better than that.

Dave Fair
Reply to  Dan M
February 3, 2021 1:21 pm

I agree that the whole data period (1979-2020) should be used; all the data are of similar quality and a longer time frame avoids over emphasizing short trends. With surface data, especially SSTs, data are shakier further back.

Reply to  Dave Fair
February 4, 2021 10:13 am

I would rather see the global surface + air-over-sea average of 14°C be used as baseline 0 anomaly on ALL global T charts (even stupid GISS) and absolute temp values used also.

donald penman
Reply to  Dan M
February 4, 2021 4:31 pm

Why not take the average for all the period and use that? When the temp. is above the average it is warming below it is cooling and the average will go up or down with long term changes which I thought was what we wanted to know.

Tim Gorman
Reply to  donald penman
February 4, 2021 5:24 pm

What data are you going to use to find the data? Are you going to all the data points available in new stations that record one minute data in order to calculate an average? Using (Tmax-Tmin)/2 is not finding an average, it is finding a mid-range. Since the daily temperature profile approaches a sine wave, Asin(t) the actual average is something like .67(A). The mid-range value is like a DC offset on an AC signal. It doesn’t really tell you much about the signal.

donald penman
Reply to  Tim Gorman
February 5, 2021 1:46 am

I was just thinking of monthly and yearly data which of course is an average but we all know that. I hear some calling a record high temperature for a particular day but I think that goes to far.

Tim Gorman
Reply to  donald penman
February 5, 2021 5:22 am

Monthly and yearly data are averages of daily mid-point calculations. Since daily mid-point calculations are not an average daily temperature then monthly and yearly averages of mid-point calculations carry the same problem along with them – they really don’t tell you much.

It’s why I advocate for the use of degree-day calculations which are the integral of the daily temperature profile. You get the area under the temperature profile which is far more useful in determining actual climate.

Matthew Sykes
February 3, 2021 3:04 am

Holocene Climatic Optimum, 3 C warmer. Grapes growing in Norway, the Sahara a green forest, with lakes and huge rivers.

Even if we get 3 C from doubling CO2, whats the problem?

Bellman
February 3, 2021 4:28 am

This is the 13th warmest, or 31st coolest January. It’s the coldest January since 2014.

The last two months have both been slightly below the long term trend line, so makes little difference, but expect this will change as we move deeper into La Niña.

The change in base period has no noticeable effect on the long term trend, 0.137°C / decade. But there will be slight changes between individual months, so might have a slight effect on short term trends.

Lord Monckton’s pause now starts a month earlier, in August 2015, which is also the last month of the old pause.

It will be interesting to see how 2021 compares with the previous La Niña year of 2018, this was 0.225°C in old money, and 0.088°C in new.

(All figures are my unofficial recalculation to the new normal.)

Bellman
Reply to  Bellman
February 3, 2021 4:33 am

A comparison of the changes to the base period:

Old base period

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New base period

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Bellman
Reply to  Bellman
February 3, 2021 4:40 am

Interesting trivia, the change to the annual base is 0.137°C, exactly the same as the linear trend, per decade, of the entire data set..

Last edited 7 months ago by Bellman
Derg
Reply to  Bellman
February 3, 2021 5:08 am

What is strange is that climate models cannot predict any of this…instead it’s a range 😉

A + B = well it’s kinda between C and D

Nick Schroeder
February 3, 2021 5:35 am

+0.15 C per decade
PER DECADE!!
Aka 0.015 C per year.

And what’s the error/uncertainty band?

Even in a formal lab setting with precision instruments and a calibration program measuring temperatures with a 0.01 resolution/precision/accuracy is challenging.
For the run of the mill instrumentation used in daily applications 0.1 C resolution is about it.

BTW me & my BSME  collected P/T/W/Q data with a wide variety of instrumentation and ran equipment and system performance monitoring programs in various power plants for decades.

This is a case of thousands of 2 and 3 significant figure data points averaged out to 5 & 6 signif figure w 2 or 3 decimal points.

Besides which all this bickering and hair splitting over GMST anomaly trends is pointless.

And by now y’all know why that is.

Dave Fair
Reply to  Nick Schroeder
February 4, 2021 1:26 pm

UAH is “the best game in town.” Similar to the crooked dice game as being “the only game in town.” We deal with what we have, Nick; one is either in the game or one is not. Constantly bitching about the rules just gets one labeled a crank. Use the rules to your benefit.

Roger Knights
February 3, 2021 6:58 am

Roy: How about including not only the current baseline in your chart but also the preceding one?

TallDave
February 3, 2021 7:03 am

FFS stop using arbitrary anomalies that keep changing and just report the freaking absolute temperature

if you really want a baseline, fine, but at the very least label a y-axis with ACTUAL temperatures somewhere

Last edited 7 months ago by TallDave
Clyde Spencer
Reply to  TallDave
February 3, 2021 10:15 am

Why keep moving the baseline when the argument is that we are experiencing post-industrialization warming? The oldest 30-year period with reliable data should be made the de-facto baseline and not changed. That way, various reports can be compared regardless of when they were published. Moving the baseline is just stirring the pot!

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