Global Temperature Trend Update: August 2011

Every month University of Alabama in Huntsville climatologists John Christy and Roy Spencer report the latest global temperature trends from satellite data. Below are the newest data updated through August, 2011.

Global climate trend since Nov. 16, 1978: +0.14 C per decade

August temperatures (preliminary)

Global composite temp.: +0.33 C (about 0.59 degrees Fahrenheit) above 30-year average for August.

Northern Hemisphere: +0.32 C (about 0.58 degrees Fahrenheit) above 30-year average for August.

Southern Hemisphere: +0.33 C (about 0.59 degrees Fahrenheit) above 30-year average for August.

Tropics: +0.15 C (about 0.27 degrees Fahrenheit) above 30-year average for August.

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July temperatures (revised):

Global Composite: +0.37 C above 30-year average

Northern Hemisphere: +0.34 C above 30-year average

Southern Hemisphere: +0.40 C above 30-year average

Tropics: +0.20 C above 30-year average

(All temperature anomalies are based on a 30-year average (1981-2010) for the month reported.)

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Notes on data released Sept. 6, 2011:

Averaged globally, August 2011 was the third warmest August in the past 34 years, according to Dr. John Christy, a professor of atmospheric science and director of the Earth System Science Center at The University of Alabama in Huntsville. The Southern Hemisphere saw its second warmest August in that time, while it was the fourth warmest August in the Northern Hemisphere.

August maps show a large area of warm over most of the contiguous 48 U.S. States, plus Mexico and the Caribbean. Slightly warmer than normal temperatures also covered most of Europe and large portions of North Asia in August. The high temperatures over Texas, surrounding states and Northern Mexico show up even stronger when looked at as a three-month seasonal anomaly. It was a warm season in both the Arctic and the Antarctic, with winter temperatures in the Antarctic averaging as much as 3.75 C (6.75 degrees F) warmer than seasonal norms.

Warmest Augusts, Global
 Temperature Anomalies
     (degrees Celsius)

1998   0.45  
2010   0.44  
2011  0.33  
2001   0.25  
1995   0.21  
2006   0.19  
2002   0.17  
2007   0.17  
2009   0.17  
1991   0.14  
2005   0.13  
2003   0.11  
1988   0.09  
1980   0.05  
1996   0.05  
1997   0.02  
1983  -0.01  
1981  -0.02  
1987  -0.04  
1990  -0.05

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 Southern Hemisphere
August Temp Anomalies
 Warmer Than Norms

1998   0.44  
2011  0.33  
2010   0.29  
2002   0.29  
1996   0.28  
2006   0.23  
2009   0.20  
1995   0.18  
1980   0.18  
2007   0.17  
1991   0.17  
2001   0.14  
2005   0.09  
1987   0.03  
2003   0.01

The processed temperature data is available on-line here.

Comments

[Untermensch]

Ron, is it just my imagination, or does the longer-term curve fitting look like a sinusoidal wave, in which case, if it continues, we might see a cooling trend over the next 23 years or so (trying to do an extrapolation from the graph)? It seems that most of the warming predictions assume a linear extrapolation, but if temperatures adopt a broadly sinusoidal pattern and you happen to pick a trough and a (near) peak as your range of examination, you would get widely incorrect predictions when you move beyond that range. Is there any way to see equivalent summary data prior to 1979?

[some guy]

but if temperatures adopt a broadly sinusoidal pattern and you happen to pick a trough and a (near) peak as your range of examination, you would get widely incorrect predictions when you move beyond that range.

Absolutely true. Climatologists claim that they aren't making such a simple mistake, though, because their theories are backed up by computer models. The mistake they're making is much, much more complex.

[Papa S]

I assume the +1979 is due to satellite data. Anything before that would be ground based readings.

It will be interesting if we see a sine-wave trend continue.

[some guy]

Yeah, folks tend to trust the satellite data more because it's more consistent across the globe. Before that you have bigger error bars, but you can still see a sine-wave.

[broken clock]

Roy Spencer notes at WUWT:

Note that this month I have taken the liberty of adding a 3rd order polynomial fit to the data (courtesy of Excel). This is for entertainment purposes only, and should not be construed as having any predictive value whatsoever.

My comment:

Drawing a first order polynomial fit is equally entertaining and non-predictive. I should also add, naive statistical prediction models out perform GCMs.

[Vangel]

The data points to natural factors, not human emissions of CO2 as the driver of temperature trends. One would expect those factors to produce a cyclical rather than a linear effect.

[Samsam von Virginia]

Looks like a sine wave with a 50 year period (half-period from 1985 to 2010). I'd predict a temperature drop over the next 25 years. Time will tell...

[some guy]

That "sine-wave" becomes even more clear if you go back past 1979. About a decade ago I took a TI-83 and slapped a similar sine-wave on the temperature data from the last century. I predicted that the AGW hype would end by 2015, when temps started to fall. I still think that prediction will come true, though I may be off by a few years...

The only problem is that I still haven't read about any 50-year cycle that could be causing this oscillation. Anybody have any ideas?

[Samsam von Virginia]

Well, there is that giant ball of molten rock beneath our feet. However, 50 years seems too short for geologic processes.

[Solar Activity]

I have an idea!

[some guy]

I am aware of an 11-year solar cycle and of longer-term solar variability that does not appear to be cyclic. But I am not aware of a 50-year solar cycle.

[Torontonian]

"The only problem is that I still haven't read about any 50-year cycle that could be causing this oscillation. Anybody have any ideas?"

You might want to look up the PDO and AMO.

[some guy]

The problem that I have with the PDO and the AMO is that they seem to be out of phase with one another. It's as if the energy is shifting between hemispheres. I'm not convinced that they would cause a global oscillation in temperature, but they are certainly worth looking at.

[ElamBend]

Great! 'cause, historically, the world is always such a happier place when it gets colder...

[Samsam von Virginia]

Yeah, what Untermensch said.

[H. Reardon]

Please explain to me, again, why we should revamp the entire world economy to reverse a 0.14-deg. C per DECADE increase in global temperature? I think we'll be able to manage.

[Joshua]

The children of course. The children.

There's no problem with spending their money, but I'll be goddamned if I'm going to make them live in a fifteen hundredths of a degree warmer world!

[Richard]

My charting program, available here:

http://www.heurtley.com/richard/gtchart

produces a similar waveform with the "-poly 4" option. It's a fourth order polynomial.

My chart:

http://www.heurtley.com/richard/20110907.png

[H. Reardon]

I had a young female bartender at the local golf course, after a stretch of seasonably hot summer weather explain to me that 'an annual increase of 1-degree, after 10 years would be, like, an increase of 10 degrees!' seems she's off by 10000%.

[Fist of Etiquette]

I wish that chart would go back to Jesus time. I want to compare just how globally hot it's gotten, long term. Surely scientists can suss from the Bible the global temperature back then.

[Torontonian]

Unfortunately, the thermometer wasn't invented until the 17th century, and reliable global temperature record-keeping only goes back to around the 1850s. The satellite record (which is the source of Spencer & Christy's data set) only goes back to 1979.

For longer temperature records, scientists have to resort to proxy data. To reconstruct the last one or two thousand years they typically use tree rings and lake-bed sediments to estimate annual temperature changes. Going back many thousands to millions of years they turn to measures of isotope ratios in ice-cores and geological formations.

I'm not aware of any scientists who routinely consult the Bible for temperature data.

[some guy]

I'm not aware of any scientists who routinely consult the Bible for temperature data.

AGW alarmists have replaced the Christian Bible with their own, modern holy book.

[kinnath]

Try wikipedia. They have many graphs going back several thousand years.

There was a Roman warm period, followed by a cooling period, followed by the Medieval Warm Period, followed by the Little Ice Age, followed by the modern warming trend.

The "hockey stick" starts at the peak of the MWP, bottoms out in the Little Ice Age, and heads sharply up to now.

Depending upon which set of proxies you pick as "truth", the Roman Warm Period, the Medieval Warm Period, and current times are all at roughly the same global average temperature.

[H. Reardon]

From my understanding, climate is in a constant state of flux. That being the case, how are seasonal 'norms' established? Does this year being .33 degrees hotter than the norm have any real meaning or significance?

[shorter O2]

Does this year being .33 degrees hotter than the norm 30-year average have any real meaning or significance?

[Torontonian]

Temperatures are always reported as an "anomaly" from the average measure over a given base period (in this case 1981-2010).

Last year, UAH increased their base period from 20 to 30 years, simply because they had more satellite data available.

So, no, 0.33 degrees warmer than the average of the last 30 years is not meaningful in an absolute sense, but is valuable when comparing the temperature change to other near term variables which may affect climate (ENSO, volcanic activity, GHG concentrations, AMO & PDO cycles, solar cycles, etc.)

[Martin]

"Does this year being .33 degrees hotter than the norm have any real meaning or significance?"

Considering the planet is several million years old, I think attempts to draw any meaningful conclusions with 30 years of climate data are probably.....futile. Catnip for bellowing frauds like Al Ghore, but not helpful in a scientific sense.

[Torontonian]

"Considering the planet is several million years old,..."

Not to nit-pick over a few orders of magnitude, but I think you meant to write "billion".

[Max]

Nothing in this data mitigates the dominance of market forces, so we can all relax. Pass the sun screen.

[califronian]

Everyone argues over the wrong question when it comes to global warming.

The only valid question is "So?".

[yet another dave]

...and the answer is.... "I need more grant money!"

[Max]

Evolution is another scam to rake in the grant money. Oh, let's study minkeys to learn about ourselves! God, liberals are gullibleo

[maxine]

becuz darwin developed the theory of evolution with government grant money derp

[Joshua]

The real Max was a better speller and far more cynical & negative. he wasn't as creative though.

[Luke]

This is a good point. I guess some people would respond with "Deadly ultra-storms, massive coastal flooding, droughts, etc". However, I have no idea if any of those things are likely to happen in the foreseeable future, if at all. So I still say we should focus on feeding people and curing diseases rather than pursuing lower emissions at any cost.

[Holy Cow]

Ummm, so the earth's temp rises and falls, rises and falls, rises and falls.

CRISIS CRISIS CRISIS**

If only some sort of big nanny govt. solution was on hand to stop these temperature fluctuations!

If only the good scienticians at East Anglia University would stop emailing each other about this weekend's bar-b-que and get on the stick and stop this seeming natural planetary occurrence!

So does that graph note when the seas swelled really really high and killed us all back in '07, just like Gore predicted in '04 (just before election time!)?

[Joshua Corning]

I want you all to understand that the third hottest august in a 30 year period can only happen once in a 30 year period....

It should also be noted that the 27th hottest August in a 30 year period can only happen once in a 30 year period.

[Mr. Mark]

Viking farms have been excavated in the permafrost of Greenland.

Do you think Vikings farmed permafrost, or do you think it was thawed out then?

In any case, WE KNOW that the climate changes over time. There is no disputing that.

However, the politically-relevant issue is whether or not human beings are CAUSING global climate change.

Showing graphs of temperature changes does not tell us anything about causation.

In the absence of proof, AGW is hocus-pocus. There is no more reason for me or anyone else to believe in AGW than there is for us to believe in the Hank Johnson Guam-Tipping Theory.

File this stuff alongside oat bran muffins, fish oil, garlic, herbal supplements, tarot cards, ouija boards, crystal balls, magnetic bracelets, energy crystals, tin foil hats, and the long term solvency of social security.

Global climate change: Observed, known, true.

Anthropogenic global climate change: Hooey.

[robnbc]

Lets face it, when 97% of the worlds top climate scientist are 95% certain that burning fossil fuels is moving us toward a +2 degree tipping point in climate change, its a good bet that we have a serious problem. Lets get past these fossil fuel funded talking points and seriously discuss what policies will best insure that our children have a hospitable climate in which to raise their children. We owe them that!