Global Surface Air Temperatures

[Hefaistos]

His source is here .
https://oz4caster.wordpress.com/monthly-trends/
(right click on an image and google search will find a source )
From the same page as the image .

The pattern of temperature trends for the Southern Hemisphere middle latitudes and Antarctic is not consistent with hypothesized significant man-made global warming.  Since carbon dioxide concentrations are relatively uniform across the globe on a time scale of years and show persistent upward trends since 1979, these flat and downward temperature trends indicate that hypothesized man-made global warming is not dominant and that other factors are likely to be more dominant over the last 40 years.  The implication is that observed upward temperature trends in the Northern Hemisphere are also being dominated by other factors.  These other factors need to be resolved before any kind of accurate future climate predictions can be made.  Predictions made assuming that man-made global warming is dominant are likely to fail.

It is a denial blog.

As to Walrus
If you want to include all of 2020 at the sk sc trend calculator you must use an end date of 2021.
 The question is global temperature trends  so I did not consider the other series with less than global coverage. RSS TTT is biased by stratospheric contamination so is not useful for  discerning the trend in global warming.
I only used the most up to date versions in all cases .1980 to 2021.
https://skepticalscience.com/trend.php
GISTEMPv4 Trend: 0.193 ±0.040 °C/decade (2σ)
Berkeley Trend: 0.192 ±0.033 °C/decade (2σ)
HadCRUT4krig v2 Trend: 0.192 ±0.035 °C/decade (2σ)
with HadSST4 Trend: 0.188 ±0.036 °C/decade (2σ)

RSSv4.0 TLT Trend: 0.218 ±0.056 °C/decade (2σ)

The out layer is Dr Roys UAH.
UAHv6.0 TLT Trend: 0.138 ±0.056 °C/decade (2σ)

Data is data. I follow oz4 because he compiles all the relevant temperature datasets.
Also he has a daily update of CFSR which is quite useful. That is just data, not really a blog.
https://oz4caster.wordpress.com/cfsr/

How strange that a compilation of temperature datasets over time should be called "denial". And that you describe all that effort that skilful people put in to provide us with all that data as a "denier blog". I just feel grateful.

As regards what he says about temperature trends over parts of the SH and relation to CO2, it's of course true. CO2 is increasing, so forcing is increasing, but still temperatures are going down. Thus, something else than CO2 is at play in those places. Makes perfect sense to me.
I wouldn't agree to his conclusion about the predictions of the global trend, but that's something that he postulates, so it's just his guess.

[kassy]

As regards what he says about temperature trends over parts of the SH and relation to CO2, it's of course true. CO2 is increasing, so forcing is increasing, but still temperatures are going down. Thus, something else than CO2 is at play in those places.

So now you claim that you never heard about long term climate variability and things like ENSO?

[KiwiGriff]

my last comment on this matter .
I sullied this blog to included a quote from your source because the passage is denial of human caused climate change quote mining portions of the passage will not change this fact .
You originally  used a number far under reality the earth is warming at about .19C a decade.  claiming only .14C a decade is  denial. Looking at short term noise in the data and claiming it signifies a hiatus in warming is also denial.
You have  a history of repeating misdirection taken from fringe sources on this blog.
I watch your comments and will without doubt catch you out again spreading bullshite you get from your loony antiscience  sources.
 
 
 

[oren]

How strange that a compilation of temperature datasets over time should be called "denial". And that you describe all that effort that skilful people put in to provide us with all that data as a "denier blog".

That the blog is a denial blog should not be doubted. It is apparent when reading between the lines and is said out loud in some of the articles and comments by the owner. That you fail to recognize this fact says something about the blog but also something about you. Your chart is made and prepared by this blog, I do not trust its accuracy in the least, and I am also certain it is presented in a way that will twist reality (scaling, color choices, adding more lines that shouldn't be there etc.). Material from denier sites should not be posted in this forum, period. And I do notice that (again) you post the material without citing its source, seemingly aware that the shady source best remain hidden.
Personally, I've had enough with these underhand dealings.

p.s. I will not link to proofs as I do not wish to add traffic to that blog and I do not wish to add denial material here. Take my word for it.

[Hefaistos]

How strange that a compilation of temperature datasets over time should be called "denial". And that you describe all that effort that skilful people put in to provide us with all that data as a "denier blog".

That the blog is a denial blog should not be doubted. It is apparent when reading between the lines and is said out loud in some of the articles and comments by the owner. That you fail to recognize this fact says something about the blog but also something about you. Your chart is made and prepared by this blog, I do not trust its accuracy in the least, and I am also certain it is presented in a way that will twist reality (scaling, color choices, adding more lines that shouldn't be there etc.). Material from denier sites should not be posted in this forum, period. And I do notice that (again) you post the material without citing its source, seemingly aware that the shady source best remain hidden.
Personally, I've had enough with these underhand dealings.

p.s. I will not link to proofs as I do not wish to add traffic to that blog and I do not wish to add denial material here. Take my word for it.

I do trust the data compiled.
But to check your claim that OZ4 might have faked something, or twisted smth, I downloaded the data I had easily available, and ran the same plot, from 2014-2020.
Here they are, both of them.

I still think that data is data, and you have to get them where they are available. OZ4 has nice updates (daily and monthly) of the relevant temperature series.

The levels might be somewhat different for some of the series, but the take-away is the same: a developing hiatus since 2016. Deny it as you please!

[Hefaistos]

As regards what he says about temperature trends over parts of the SH and relation to CO2, it's of course true. CO2 is increasing, so forcing is increasing, but still temperatures are going down. Thus, something else than CO2 is at play in those places.

So now you claim that you never heard about long term climate variability and things like ENSO?

I was commenting on the claim from KiwiGriff that the statement in question at OZ4 is some kind of 'denial'. It isn't. OZ4 just claims the obvious.

[oren]

My own chart, data downloaded from NASA at https://data.giss.nasa.gov/gistemp/graphs_v4/

Taking the largest El Nino in two decades and using it to define a baseline for a hiatus is not comparing apples to apples, and is a simple denialist act. We've had enough of that in the years after 1998-1999. You should go into moderation. Disagreements are okay and even encouraged, denialism is off limits.

[Hefaistos]

My own chart, data downloaded from NASA at https://data.giss.nasa.gov/gistemp/graphs_v4/

Taking the largest El Nino in two decades and using it to define a baseline for a hiatus is not comparing apples to apples, and is a simple denialist act. We've had enough of that in the years after 1998-1999. You should go into moderation. Disagreements are okay and even encouraged, denialism is off limits.

Oren, I have repeatedly said that I don't deny anything here! I took a temperature chart from a site that provides a very nice collection of daily and monthly updates. Such sites are rare! I always look for data, not for some opinions expressed on a site. Words are cheap, good data collections are rare. For me data is data.

Another thing is if data is manipulated, so I checked that and compared with raw data. All is fine with the data from OZ4, as well as with his continuosly updated presentation of data on charts. See my comparison above.

As for 1998/99, sorry, I wasn't around then, don't know too much what you're talking about.

As for defining a baseline for a hiatus, it's a good principle to start from a well-defined top and then follow it until that top is taken out, or to a subsequent top, (or, similarily, from a bottom to a bottom). This is just data analysis, but you claim this is denialism? 
Bizarre.

[blu_ice]

Could we drop the "hiatus" please? Everybody knows global temps are noisy. A new record year is not followed by a record year after a record year, even in a warming world. Variability is not hiatus.

[Rodius]

My own chart, data downloaded from NASA at https://data.giss.nasa.gov/gistemp/graphs_v4/

Taking the largest El Nino in two decades and using it to define a baseline for a hiatus is not comparing apples to apples, and is a simple denialist act. We've had enough of that in the years after 1998-1999. You should go into moderation. Disagreements are okay and even encouraged, denialism is off limits.

Oren, I have repeatedly said that I don't deny anything here! I took a temperature chart from a site that provides a very nice collection of daily and monthly updates. Such sites are rare! I always look for data, not for some opinions expressed on a site. Words are cheap, good data collections are rare. For me data is data.

Another thing is if data is manipulated, so I checked that and compared with raw data. All is fine with the data from OZ4, as well as with his continuosly updated presentation of data on charts. See my comparison above.

As for 1998/99, sorry, I wasn't around then, don't know too much what you're talking about.

As for defining a baseline for a hiatus, it's a good principle to start from a well-defined top and then follow it until that top is taken out, or to a subsequent top, (or, similarily, from a bottom to a bottom). This is just data analysis, but you claim this is denialism? 
Bizarre.

What a strange reply.

1 - the site you get the data from is biased and a denier site. This has been said multiple times and highlighted that it is manipulated. Yet you persist.

2 - Data is not data..... it is information to interpret a situation. The data, in itself, is not some magical way to give a black and white answer, yet you seem to think that it is.

3 - As for 1998/99.... and you not being around means you don't know much about it.... are you saying that nobody should know anything about anything before they were born? This type of thinking is bizarre.

4 - as for baselines, my understanding is, in climate anyway, you need 30 years worth of averages to get a baseline. A baseline is restarted when a new record is created... that is just a load of bullshit. There are several baselines you can use, but none of them are based on setting it at the last record.

[oren]

The false hiatus was not born in 1998-9, it was born in the mid-2000s, just as the current false hiatus was born in 2020. I haven't been around then either, but this site and the Internet was full of discussions about said false hiatus ("faux hiatus" would get you many search results). Ignoring a monster El Nino that comes along every couple of decades and natural variability that has swings of several years and naming a short term hiatus is denialism by the book.

[Neven]

Please, stop trolling, Hefaistos. Statistical manipulation is not 'data'.

[grixm]

I think this discussion is just the result of an innocent misunderstanding, more specifically the semantics of the word "hiatus". It does not seem to me that Hefaistos is trolling, but merely used that word in a somewhat inaccurate manner, but then doubled down when met with overly harsh knee-jerk responses like calling him a troll or denier because of it. This reaction is normal and therefore if common understanding is the goal then accusations like that should be avoided.

In short: Have we seen periods after a peak in air temperature where there are no new record for a few years afterwards? Yes. Does that mean that the warming actually stopped in these periods, in other words that global warming took a "hiatus"? No, it was just statistical noise. It seems to me that everyone including Hefaistos agrees with this, so there is really no reason to argue.

[pleun]

if you use the word "hiatus" then you have an agenda, nothing innocent there. Especially if you have a history of this kind of discussion.

[blu_ice]

This was textbook trolling.

Instead of Global Surface Air Temperatures people are now discussing whether there is a hiatus or not. Discussion was successfully derailed to a denier talking point.

[Hefaistos]

if you use the word "hiatus" then you have an agenda, nothing innocent there. Especially if you have a history of this kind of discussion.

Sorry, shouldn't have used 'hiatus' if i knew it was so controversial. Could have used 'interregnum' instead Where the El Ninos seem to be the rulers, at least in short terms.

My agenda is just that i'm learning all i can about climate. Currently, i've become more interested in the natural variability of the climate, and how it relates to general trends.

The forum is about an exchange of information and thoughts, that's a great learning experience to be able to have such discussions. Thanks!

[Hefaistos]

I think this discussion is just the result of an innocent misunderstanding, more specifically the semantics of the word "hiatus". It does not seem to me that Hefaistos is trolling, but merely used that word in a somewhat inaccurate manner, but then doubled down when met with overly harsh knee-jerk responses like calling him a troll or denier because of it. This reaction is normal and therefore if common understanding is the goal then accusations like that should be avoided.

In short: Have we seen periods after a peak in air temperature where there are no new record for a few years afterwards? Yes. Does that mean that the warming actually stopped in these periods, in other words that global warming took a "hiatus"? No, it was just statistical noise. It seems to me that everyone including Hefaistos agrees with this, so there is really no reason to argue.

No, I disagree with the bolded statement, it's not 'statistical noise'. Simply because we know that a lot of the temperature variability is caused by the ENSO. That is not to be defined as noise.

But what rules the ENSO?
What decides when there is a strong Nino, or a strong Nina?
What's the relation between ENSO and longer term ocean cycles such as the PDO or the AMO?
And what rules them?

My impression is that there is a lot to learn for everyone here, we simply don't know too much about these things. At least I don't

[grixm]

No, I disagree with the bolded statement, it's not 'statistical noise'. Simply because we know that a lot of the temperature variability is caused by the ENSO. That is not to be defined as noise.

ENSO is most certainly statistical noise. Just because there is a causality involved doesn't mean that the underlying cause at the bottom of the causality chain is not chaotic randomness. And all data points towards ENSO being exactly that, due to how difficult it is to forecast years into the future, like weather itself.

[The Walrus]

No, I disagree with the bolded statement, it's not 'statistical noise'. Simply because we know that a lot of the temperature variability is caused by the ENSO. That is not to be defined as noise.

ENSO is most certainly statistical noise. Just because there is a causality involved doesn't mean that the underlying cause at the bottom of the causality chain is not chaotic randomness. And all data points towards ENSO being exactly that, due to how difficult it is to forecast years into the future, like weather itself.

You are both right.  ENSO, in and of itself, is not statistical noise.  ENSO is a real deviation around the average temperature.  It is not noise in the same way that sinusoidal deviations around the central point are not noise.  However, when viewed over the long term, ENSO could be considered noise in that it does not affect the overall trend.  Either way, ENSO will affect statistical measurements over both the short- and medium- terms.  Starting or ending with a strong El Niño or La Niña will affect the numbers.

[oren]

Cross-posting from one of the Cryosphere threads.

    Back in November, I posted a chart showing predicted end-of-year 2020 annual NASS GISS-Temp (global average surface temperature) anomaly vs. 1850-1900 average AFTER removing short-term influences of ENSO (El Nino/La Nina), solar cycle, and aerosol (Mauna Loa).  The final two months of 2020 came in slightly warmer than expected.  Here is how 2020 looks with all 12 months of NASA GISS values.

     The observed 2020 value was a statistical tie with 2016 (with 2020 at 0.014 C warmer) as the warmest year in modern record (since 1880).  But when you subtract out temporary influences of ENSO/solar/aerosol, to estimate an underlying systemic temperature, then 2020 was the warmest year by a larger margin.  2020 was 0.109 C warmer than 2019, which replaces 2016 in 2nd place when you filter out the estimated effects of ENSO/solar/aerosol.

     In the Real Climate blog, Gavin Schmidt of NASA says the uncertainty in the annual GISS-Temp annual anomaly is 0.05C.  The uncertainty for estimates that include additional factors (ENSO/solar/aerosol) each with its own uncertainties is probably larger.  But at least Schmidt's 0.05 uncertainty for annual GISSTemp anomaly gives us a frame of reference. 

     At 0.109 C warmer than the previous warmest year, it seems likely that 2020 was indeed the warmest year in the modern record.  Schmidt also said that the estimate of global average surface temperature itself has an uncertainty of ca. 0.5C, so this conclusion may be a distinction without a meaningful difference.  Especially when you remember that the surface temperature does not equal the temperature of the planetary system as whole.  There is a lot more heat energy stored in the ocean than in the atmosphere.  But for tracking the climate change influence driving Arctic Sea Ice, the NASA GISSTemp may be as good an indicator as any (says a guy with no training in climate science).

[jai mitchell]

Hefaistos


Globally averaged surface temperature is a highly variable, multi-input metric.  This means that, as a complex system it cannot be treated as a simpler metric, like a stock value.  You don't do a chart based on a reported peak and then draw your support levels to predict where it will go from there.

To determine the long-term trend you have to do a fairly complex statistical analysis that takes the average differential for each year over the last 30 years, then take the average differential for each 2-year period over that same time, then a 3-year differential and so on and then Then you get the variance of the metric. and using this variance you can determine what the statistical probability of future warming will be and if a previous peak or trough is far above (or below) the statistical trend-less variability.

It is this reason that many scientists say that we cannot yet determine that global warming (temperatures) are accelerating over the last 2 decades.  Even though on a straight ling graph from the 1980's onward we can see that the acceleration is fairly obvious.  The statistical significance of a trend takes over a decade to show itself.