Global Temperature Trend Upate: December 2010—Warmest Year Or Not?


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 December, 2010. Last year finishes in a statistical tie with 1998 as the warmest year in the past 32 years. As Spencer notes: 1998 (+0.424 deg. C) barely edged out 2010 (+0.411 deg. C), but the difference (0.013 deg. C) is nowhere near statistically significant.

Is it getting hot in here?

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

December temperatures (preliminary)

Global composite temp.: +0.18 C (about 0.32 degrees Fahrenheit) above 30-year average for December.

Northern Hemisphere: +0.21 C (about 0.38 degrees Fahrenheit) above 30-year average for December.

Southern Hemisphere: +0.15 C (about 0.26 degrees Fahrenheit) above 30-year average for December.

Tropics: -0.22 C (about 0.40 degrees Fahrenheit) below 30-year average for December.

November temperatures (revised):

Global Composite: +0.27 C above 30-year average

Northern Hemisphere: +0.37 C above 30-year average

Southern Hemisphere: +0.17 C above 30-year average

Tropics: -0.12 C below 30-year average

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

Notes on data released Jan. 6, 2011:

2010 finished in a photo finish with 1998 for the warmest year in the 32-year satellite temperature record, according to Dr. John Christy, professor of atmospheric science and director of the Earth System Science Center at The University of Alabama in Huntsville. 2010 was only 0.013 C cooler than 1998, an amount that is not statistically significant.

Both 1998 and 2010 were years in which an El Nino Pacific Ocean warming event raised temperatures around the globe. In recent months a La Nina Pacific Ocean cooling event has been building; temperatures in the tropics were cooler than seasonal norms for both November and December.

Annual Global Average Anomaly

(Warmest to Coolest)*

 1. 1998  +0.424 C
#2. 2010  +0.411 C
 3. 2005  +0.251 C
 4. 2002  +0.220 C
 5. 2009  +0.187 C
 6. 2003  +0.185 C
 7. 2006  +0.175 C
 8. 2007  +0.168 C
 9. 2001  +0.112 C
10. 2004  +0.104 C
11. 1991  +0.025 C
12. 1987  +0.018 C
12. 1995  +0.018 C
14. 1988  +0.017 C
15. 1980  -0.003 C
16. 1990  -0.017 C
17. 1981  -0.040 C
18. 2008  -0.041 C
19. 1997  -0.044 C
20. 1999  -0.051 C
21. 1983  -0.056 C
21. 2000  -0.056 C
23. 1996  -0.071 C
24. 1994  -0.104 C
25. 1979  -0.165 C
26. 1989  -0.202 C
27. 1986  -0.239 C
28. 1993  -0.240 C
29. 1982  -0.245 C
30. 1992  -0.284 C
31. 1985  -0.304 C
32. 1984  -0.348 C

*Compared to 30-year seasonal norms

The globe continues to warm unevenly, with warming increasing as you go north: The Arctic Ocean has warmed an average of 1.66 C (about 2.99 degrees Fahrenheit) in the past 32 years. By comparison, the Antarctic continent has cooled about 0.29 C (more than half a degree Fahrenheit) during the same time.

The continental, contiguous U.S. has warmed by about 0.67 C (about 1.21 degrees Fahrenheit) since 1979.

Climate trends since November 1979
(Degrees C per decade)

Globe   Land   Ocean
+0.14  +0.18  +0.12

 NH     Land   Ocean
+0.21  +0.24  +0.17

 SH     Land   Ocean
+0.08  +0.07  +0.08

Trpcs   Land   Ocean
+0.08  +0.10  +0.07
(The tropics extend from 20N to 20S latitude)

NoExt   Land   Ocean
+0.27  +0.28  +0.25
(NoExt goes from 20N to 85N latitude)

SoExt   Land   Ocean
+0.07  +0.04  +0.08
(SoExt goes from 20S to 85S latitude)

NoPol   Land   Ocean
+0.47  +0.44  +0.52
(The North Polar region is from 60N to 85N latitude)

SoPol   Land   Ocean
-0.07  -0.09  -0.06
(The South Polar region is from 60S to 85S latitude)


Technical Note:

Beginning with this Global Temperature Report, the baseline period used to determine seasonal norms changes. It has been the 20-year (1979 to 1998) period at the beginning of the satellite record. Starting this month the report will use a new 30-year (1981 to 2010) reference average to match the climatological period normally used with climate data by the U.N.'s World Meteorological Organization.

"This will not affect the long term trend, which is the most important of the numbers we produce, but will 'reshuffle' anomalies to reflect the new base period," said Christy.

As Christy's colleague Roy Spencer further explains:

This change from a 20 to a 30 year base period has 2 main impacts:

1) because the most recent decade averaged somewhat warmer than the previous two decades, the anomaly values will be about 0.1 deg. C lower than they used to be. This does NOT affect the long-term trend of the data…it only reflects a change in the zero-level, which is somewhat arbitrary.

2) the 30-year average annual cycle shape will be somewhat different, and more representative of "normal" of the satellite record than with 20 years; as a result, the month-to-month changes in the anomalies might be slightly less "erratic" in appearance. (Some enterprising person should check into that with the old versus new anomaly datasets).

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  1. Couldn’t this been combined with the tides thread?

    1. No, the tides thread is already funny enough.

    2. I could not find the tides thread.

      Link please.

      1. It’s the Bill O’Reilly thread.

  2. Global climate trend since Nov. 16, 1978: +0.14 C per decade[…]

    … compared to the baseline. What’s the baseline, you ask? It’s an arbitrary chalkline that’s supposed to give the chart some sense of dimension, as one cannot arrogantly assert the baseline represents an optimal or ideal temperature, or a goal to achieve – NOBODY can know what that would be.

    1. Actually they are using the 30 year average 1981-2010. So the area above and below zero from 1981-2010 are equal. The more intersting question is “how long is a cycle?” I mean, if cycles are 10 years long, this is a big fucking deal and warming is real. If a cycle is 1000 years, there’s no way of knowing whether this is representative of the larger cycle or not. The other question is “how many cyclical variables affect this?”. If seasons are it, this would be strongly indicative of AGW. If solar output, geothermal cycles, atmospheric moisture transfers, etc. over varied cycles all have detectable effects, its way too early to say whether human activity is part of this signal and how much.

    2. and so continues the stupid accusations of amateur skeptics (old mex) about the motives of professional skeptic Roy Spencer.

      Hey old mex, wake the fuck up. This graph supports a skeptics view points…with the added bonus that it is scientifically defensible. Which is very unlike the graphs produced by global warmers.

    3. s one cannot arrogantly assert the baseline represents an optimal or ideal temperature, or a goal to achieve – NOBODY can know what that would be.

      Like I tried telling you libtards

      The tide comes in and the tide goes out.

      Now go suck ron paul’s cock.

  3. not only the hottest, but studies also indicate the higher temps cause autism.

    1. So the reduction in sea piracy causes global warming which in turn causes autism.

      Got it.

      1. Only if the pirates were vaccinated for scurvy, ye briny dog! Argh!

        1. Your modern pirates are more likely to say durka durka durka than Arr.

    2. I take it you were born in 1998?

  4. where’s the hockey stick lebowski?

    1. You have to selectively edit the data to start at the peak of the medieval warming period to show the decline in temperature down to the little ice age and back up to current temperatures to create the hockey stick.

    2. This is what happens when you fuck a peer review process in the ass.

      1. You get lawyers?

  5. To me, absolutely nothing about this whole ridiculous exercise is statistically significant, from the absurdly small time frames we’re talking about to the fractions of a degree Celsius in the so-called “average global temperature”. Needless to say, if 2010 had apparently beat out 1998 by +0.013 degrees instead of losing out by -0.013 degrees, the Chicken Littles would consider that significant enough to shriek hysterically.

    Oh and by the way, if you’re out there reading this Mclaren, I told you that the year doesn’t go from January to Novemeber. F’ing retard.

    1. So… All those that said that 2010 was THE warmest year are going to come and say they were wrong.

      I’m waiting.

      1. It depends on which temperature record you look at. GISS, CRU and NOAA haven’t released their analyses yet, but even if they were all to show 2010 coming in as equal or slightly behind 1998 you still have to look at the larger picture.

        1998 was a record El Nino year, meaning the oceans were pumping a tremendous amount of heat into the atmosphere. In 2010 we had an El Nino about half as powerful, a strong La Nina sucking heat from the atmosphere in the latter part of the year AND the deepest solar minimum in a century. And still we had one of the two warmest years on record.

        1. I’m not saying that I don’t believe you, but links pls?

          1. You can read about the low level of solar activity here.

            Data regarding the current La Nina here

  6. Fucking weather- how do it work?

    1. Tides.

      1. You know. God.

        1. You accidentally dropped a letter from your name, Ms. Palin.

          Hey, that could be the slogan for your White House run: Palin bringing on the pain!

          Or a WWE cage match. Whatever.

  7. I’ve updated my chart-making program to reflect the new 30 year baseline. If you want to make your own charts of the UAH data, with optional polynomial and FFT fitting, you can download the program here:

  8. Some time ago someone posted a link to a web site that had historical temperature charts that zoomed out logarithmically. The time-periods were selected to alternate between making it look like the earth was going to freeze and the earth was going to fry. At the end it was obvious that everything that’s happened for the last 1000 years is just noise.

    Does anyone have that link?

    1. I know what you are talking about.

      Here is the closest thing i could find in my bookmarks…i will check the ones i have at home when i get there.…..00-new.png

      1. Good Lord!

        Get a life you dweeb.

  9. [standard rant not applicable]

  10. Waiting for Joe Romm to report on 2010 being the hottest year ever

  11. AAAAGGGGHHH it’s a TENTH of a degree warmer than it “should” be! We’re all gonna DIIIIIIEEEEE

    1. Oh crap, there goes a tiny fraction of the polar ice caps! Everyone! Please take a step back from the ocean! Just a tiny, tiny step back. Right. That’s good.


    2. We have a right to our God-given stable seasons.

  12. Until you change those measurements to Fahrenheit this whole article means nothing to me and all real americans.

  13. I have a theory, which is my own, that temperatures go down, and then they go back up, and then they go down again. This chart confirms my theory.

  14. Looks to me like about all you can say is that this year’s El Nino was milder than the last one.

    Really. I think that’s really all you can say about this chart.

    1. It’s really a MAD fold-in.
      If you do it right, it’s a smiley face that says “HA! You just ruined Your MAgazine!”

      1. Ha! That took me back to my childhood. Thanks.

        It also made me feel old. Damn you to hell!

    2. I think that’s really all you can say about this chart.

      well you can also say that over the last 30 years there has only been a 0.14 degree per decade of warming which is well below the warming predicted by the IPCC and other global warmers who predict a 0.3 to 0.6 dgree per decade increase.

      You can also say that a .14 degree per decade increase is statistically insignificant.

      and lastly you can say that a .14 degree increase per decade over a 100 year period will cause only about a foot of sea level rise.

      1. Joshua,

        The satellite record shows average warming as 0.14C per decade, while the instrumental record shows 0.17C per decade. The IPCC projects warming of 0.2C for the next decade or two:…..ns-of.html

        If you take a look at the link, you’ll see the chart projects warming in the 0.4-0.5C range only in the worst case scenario, which is judged to be unlikely.

        1. If you take a look at the link, you’ll see the chart projects warming in the 0.4-0.5C range only in the worst case scenario, which is judged to be unlikely.”

          Denier! Don’t you know that if you don’t believe that the apocalypse is coming, that you are a dirty little non science denier idiot!?!?

        2. The IPCC projects warming of 0.2C for the next decade or two

          They start at 2000. It is 2011 today…so by the “next decade” you mean last decade.

          If you take a look at the link, you’ll see the chart projects warming in the 0.4-0.5C range only in the worst case scenario, which is judged to be unlikely.

          Today’s global green house gas emissions are at the A1F1 estimates. ie the worst case scenario.

          The funny thing is US emissions have peaked….it is china and India where most of the green house gas emissions have increased.

          1. Possibly because we’ve outsourced much of our manufacturing to those other countries.

          2. The link is to the 2007 IPCC report, and the projections don’t begin until the decade of 2010-2020. The emissions scenario chart does reference year 2000 CO2 concentrations, but only for purposes of comparison (i.e. this is how much warming we get if we stabilize at year 2000 concentrations, this is what we get in the A1F1worst case scenario by the year 2090-2099).

  15. Why the hell would they go to the third decimal if the second isn’t even significant?!

  16. Stop taking temperatures already! The science is settled! No more information is needed! It’s settled I tells ya, settled! Leave it alone!

  17. What has been written in the Good Book is coming to be true.

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