A little perspective on the U.S. and global temperature records

GISTEMP ^ | 08/10/2007 | cogitator

[cogitator]

There's been some ballyhoo about an adjustment to the U.S. temperature record from GISS (it will be interesting to see if the NOAA record will require a similar adjustment). What some are apparently forgetting is that the U.S. warm temperature anomaly (the Dust Bowl) in the 1930s, and the cooling of the 1960s and 1970s, was somewhat disconnected from the global temperature trends. The two graphs below illustrate this.

Global land-ocean temperature record

Note that there is also a global meteorological-station-only record; graph can be found at the Source URL.

U.S. Temperature Record

A substantial difference can be perceived.

But why?

[Important note: First notice that the global land-ocean temperature record includes the anomalous tropical warmth of the 1930s into the 1940s, which was apparently "magnified" (see below) by interactions with the North American land surface.]

What Caused the Dust Bowl in the US Midwest in the 1930's?

Was the Dust Bowl predictable?

An excerpt from the latter link is provided below:

"The inability to correctly model the spatial pattern of the Dust Bowl drought, and its deviation from the typical pattern of tropical SST-forced drought, makes us wonder how unusual the Dust Bowl pattern was. Analyses of instrumental data since the mid nineteenth century - shows that none of the other five multiyear droughts in this interval (1856-65, 1870-77, 1890-96, 1948-57 and post 1998) had a similar pattern. For a longer record we examined the updated version of the gridded tree ring records within the North American Drought Atlas. Computation of the spatial correlation between the Dust Bowl pattern and six year low pass filtered data revealed only three prior droughts that had an anomaly correlation exceeding 0.4 (Figure 4). All were in the Medieval period. No other droughts had an AC exceeding 0.31 presenting a clear separation between Dust Bowl type droughts and the more commonly occurring pattern with a center in the Southwest and southern and central Plains."

MY SHORT SUMMARY: The warm temperatures of the 1930s were extremely unusual in the United States. This has been known for quite awhile. The adjustments to the United States temperature record do not significantly change the current climate understanding: i.e., the 1930s were anomalously warm in the United States for one particular and unusual reason; the current warm temperatures in the United States are linked directly to the warming trend over the entire globe (with some minor exceptions like central Antarctica).

I don't really want to be attacked for my political motivations for posting this, because I don't have any. I will not respond to any non-scientific discussion - that's why I posted this in the "Science" forum and not "News/Current Events". I'm attempting to help people to understand the issue better, and not to get "carried away" with the latest "global warming refutation". My advice: don't get too excited. Keep reading. Try to separate knowledge from belief.

Oh yeah; you can also read my profile.

[avacado]

Thanks for the link! I was laughing the whole time I read it. Basically, they decided to treat the Earth as a non-equilibrium system and decided to use REAL data and found that the Earth will not be heating up.

This whole “global warming” debacle is sending real science back to the dark ages... especially with buffoons like Al Gore (a non scientist) leading the charge.

[P-40]

but there are many examples in the history of science where a recognized "great mind" really did have insight into breakthrough knowledge

Many laughed at Tesla. Even Edison had some rather unkind things to say about him. :)

[P-40]

especially with buffoons like Al Gore (a non scientist) leading the charge.

Al Gore is the ultimate anti-environmentalist, anti-conservationist, anti-scientist, etc. He's the Court Jester on PCP.

[qam1]

The two graphs below illustrate this.

Your 1st graph is BS, it's showing 2002 was as warm as 1998 and 2004 was nearly a whole .1 higher than 1998, which is news to me, someone is playing with the numbers there. Not to mention they always clip the end off the 5 year moving average at 2003 so you don't see the leveling off at the end.

MY SHORT SUMMARY: The warm temperatures of the 1930s were extremely unusual in the United States. This has been known for quite awhile.

Translation: Anything that embarrassingly contradicts global warming we will just dismiss and chalk it up to being unusual or an anomaly, this way we can still keep our religion and continue to push for world socialism

The adjustments to the United States temperature record do not significantly change the current climate understanding

The hell it doesn't. Back in that time period the United States was pretty much the only country keeping accurate temperature records on a consistent basis(i.e. How many weather stations were there in China, Africa, South America, Antarctica, etc. consistently taking accurate temperature readings in the 1930's). If they can't get the United States right, why should we believe the rest of the world is without error?

I don't really want to be attacked for my political motivations for posting this, because I don't have any.

You post from and believe every word without question from Realclimate.org, which is hosted by Al Gore's very own campaign manager and you have no political agenda, suuurrre.

[cogitator]

Then a correction in the bias was done to the data set and it showed the stratosphere temperatures to be warming and the scientists said that that was exactly what they had expected to see the stratosphere temperatures warming. Can't have it both ways.

Yes, but you can be confused between the troposphere and the stratosphere, which is what you've done here. The stratosphere has been cooling since satellites started measuring -- primarily due to ozone depletion and secondarily due to global warming. The troposphere was not showing warming (in the Spencer & Christy MLS data set), but they adjusted it -- and 1998 kicked it higher -- and now it does. Other groups analyzing the same data get higher lower troposphere warming trends than Spencer and Christy do.

I also see from the RealClimate link that they used a weighted formula for temperatures values to arrive at the "average" global temperature.

This is required for areas with sparse spatial coverage, for one thing.

[cogitator]

Oops, 1998 is no longer the warmest year on record.

In the United States (which is why I wrote this little posting). Globally, 1998 was much warmer than any other year since 1880 (whenever the official start year of the instrumental record is) and will be -- until there's another strong El Nino event. The year that happens will be the new global temperature record year.

I'll go beyond the IPCC and say that I have 100% confidence in my final statement above, beginning with "until". The only factor that could change that outcome would be a true decrease in solar radiance. I don't see that happening, thought some solar scientists have made that prediction. (And if they're right, it's good for the globe.)

[dirtboy]

I don't see that happening, thought some solar scientists have made that prediction. (And if they're right, it's good for the globe.)

The millions who died of cold and starvation during the Little Ice Age might beg to differ there.

[avacado]

"Yes, but you can be confused between the troposphere and the stratosphere,..."

You are right... I had them mixed up. But it still leaves me puzzled that before the correction they explained the cooling as a valid result of global warming. And now they do a correction and and get a warming trend and explain that as valid.

"This is required for areas with sparse spatial coverage, for one thing."

Yes I know. And attempting to "regularize" data based on a simple weighting algorithm is not very accurate whatsoever.

[cogitator]

Your 1st graph is BS, it's showing 2002 was as warm as 1998 and 2004 was nearly a whole .1 higher than 1998, which is news to me, someone is playing with the numbers there. Not to mention they always clip the end off the 5 year moving average at 2003 so you don't see the leveling off at the end.

According to the GISS global analysis, 2005 (not 2004) was warmer than 1998. You missed the point (2003) that's mostly covered by the red moving average line. For more on that:

Global Temperature Trends: 2005 Summation

"The highest global surface temperature in more than a century of instrumental data was recorded in the 2005 calendar year in the GISS annual analysis. However, the error bar on the data implies that 2005 is practically in a dead heat with 1998, the warmest previous year."

There is indeed a discrepancy between the 2005 temperature anomaly shown at the link above and the one shown on the graph to which your posting refers (the one in my original composition). Both of these are directly linked from GISS. The temperature anomaly in 2005 is above 0.6 C in the graph posted here, and below 0.6 C in the GISS 2005 temperature summation. I have no idea if this is a plotting error or due to a revision to the data. I have always based my understanding on the 2005 summation, which indicated that 2005 was very slightly warmer than 1998 in the GISS analysis (NOAA had 2005 just below 1998). [Note that the 2005 summation probably hasn't been revised since January 12, 2006. The graph at the top of the article was revised on January 8, 2007. I find that interesting, because it may imply that in the current GISS analysis, 2005 is now warmer than originally reported in the 2005 summation!]

As for 2002: Global Temperature Trends: 2002 Summation

Translation: Anything that embarrassingly contradicts global warming we will just dismiss and chalk it up to being unusual or an anomaly,

I still have yet to see anything that embarrasingly contradicts global warming. Your misconceptions certainly don't.

Back in that time period the United States was pretty much the only country keeping accurate temperature records on a consistent basis(i.e. How many weather stations were there in China, Africa, South America, Antarctica, etc. consistently taking accurate temperature readings in the 1930's)?

I refer you to the Global Historical Climatology Network and this PDF document: Global Historical Climatology Network (GHCN) quality control of monthly temperature data. Judge for yourself. From the latter document: "Despite the problems encountered with various source data sets and individual time series, evidence was repeatedly seen, in both the digital archive and in old documents such as the 1894 Deutsche Ueberseeische Meteorologische Beobachtungen in Deutsch-Ost-Afrika (Peterson and Griffiths, 1997), that weather observations were generally made very meticulously. There are 4.7 million station months of temperature data in GHCN starting in 1701 and continuing to the present. This embodies the systematic observations of our environment by tens of thousands of individuals over centuries of human history."

Speaking of RealClimate, the discussion in "6 Easy Steps" is actually quite illuminating. Did you know that there are two reasons that the GHCN temperature record is substantially unaffected by the revisions to the GISS data? See the responses to #110 and #112 to see why.

[knews_hound]

Once upon a time, way back when, I was a professional Metrologist.

NOT a Meteorologist, a Metrologist.

 My profession was measurement standards and their applications.

 When I read stories about thermometers being placed in parking lots, next to buildings and other obviously poor locations, I am forced to ask “Is any one paying attention”?

 These are fundamental and substantial issues and are at the core of this debate.

 If I cannot trust these “scientists” to simply place the instrumentation in a proper environment, how can I possibly be expected to respect their conclusions?

 The point about the algorithm used to “normalize” the data is also highly suspect.

 Does anyone remember the term G I G O?

 Without reproducible and verified standards that are open to review and inspection, I will continue to look at human caused global warming as nothing more than a religion.

 I deal in facts.

 Opinions are for the Editorial page. Cheers,

knewshound

http://www.knewshound.blogspot.com/

[cogitator]

The millions who died of cold and starvation during the Little Ice Age might beg to differ there.

It's currently a lot warmer than then. If the Sun decides to cool off a bit for the next century or so, then thank you Mr. Sun and I think human civilization has better sources of heat and more enlightened agricultural practices than in the 1600s and 1700s. We can always increase our CO2 emissions if it looks like it's getting too cold!

[dirtboy]

It's currently a lot warmer than then.

But still cooler than the Medival Warm period, a time of formerly unprecedented human prosperity that ended with the onset of the Little Ice Age.

Warm is good.

[cogitator]

But it still leaves me puzzled that before the correction they explained the cooling as a valid result of global warming. And now they do a correction and and get a warming trend and explain that as valid.

The stratosphere is cooling and the lower troposphere is warming. Both are valid results of global warming. The critical necessity of lower troposphere warming is higher (for the theory) than stratospheric cooling. Go to the bottom of this page (you can read the rest if you want):

Description of MSU and AMSU Data Products

TLT is lower troposphere, TMT is mid-troposphere, TTS is troposphere/stratosphere, and TLS is lower stratosphere. And I hope you know what the big warming bump in 1991 in the TLS was caused by.

For benefit of others, here are the TLT and TLS plots:

And attempting to "regularize" data based on a simple weighting algorithm is not very accurate whatsoever.

I defer to your expertise.

[cogitator]

But still cooler than the Medival Warm period,

Debatable and not resolvable (according to both the NAS and the IPCC) with currently available data and analyses. That is ultimately one of the main outcomes of the "hockey stick" evaluation -- beyond 400 years ago quantitative comparisons of global and regional temperature are inconclusive.

Best that can be said is that it was warm then (MWP) and it's warm now.

[dirtboy]

Debatable and not resolvableEngland had vinyards during the MWP.

Best that can be said is that it was warm then (MWP) and it's warm now.

Like I said - warm is good.

[cogitator]

English vineyards again

[avacado]

I guess my point is that while the data for the troposphere showed cooling before the known correction, scientists were putting faith in the models even though the data showed different.

And attempting to "regularize" data based on a simple weighting algorithm is not very accurate whatsoever.

"I defer to your expertise."

I am only a software engineer developing simple algorithms and doing seismic system design. But "regularization" of data is a big big issue in the seismic field and we have PhDs and double-PhDs working around the clock on algorithms. A weighting scheme is a very basic and not so good method for spatial interpolation and extrapolation.

[P-40]

Like I said - warm is good.

Not for some people.

[cogitator]

I guess my point is that while the data for the troposphere showed cooling before the known correction, scientists were putting faith in the models even though the data showed different.

And that's a very good point.

[P-40]

And that's a very good point.

My take is that most of the scientists will use tools, like models, in the best way they know how and as better methods come along they will continually reevaluate their understanding of what they are seeing. I know the IPCC is not popular here and I will admit that they are under a lot of political pressure, but many of their scientists do some excellent work and report fairly on their findings and even on the limitations of those findings. The only exception to that I readily make is to the 'statement for policy makers' because that always seems so political and should be retitled something along the lines of "statements for people who don't care what we have to say as long as we say what they want us to."