Digital Diatribes

A presentation of data on climate and other stuff

September 2008 Update on Global Temperature – RSS, Part 2

Posted by The Diatribe Guy on September 8, 2008

Please see my previous post for my normal analysis on the global temperature trends. This post is a follow-up based on taking a look at regional trends that the reader may find interesting.

It has not been lost on me that the North Pole is the hot-button issue of our day with respect to the global warming argument. It is undeniable that the last couple years had ushered in the lowest ice levels in recent memory. A nice chart that tracks these levels can be found here at the IJIS Web Site.

And yet, over the last few years, global temperatures are cooling. This indicates that the warming at the north pole is a regional, rather than a global phenomenon. I was curious as to the extent of the difference in the long-term and short-term trends by region, so I did some quick trending on the RSS anomalies by region. Below is a summary of how the trends have changed over time by region:

GLOBAL SLOPES, presented as rate of warming per Century, in degrees Celsius:
1979 01 – Current: 1.688
1983 09 – Current: 2.078
1988 09 – Current: 2.004
1993 09 – Current: 1.290
1998 09 – Current: 0.843
1999 09 – Current: 0.779
2000 09 – Current: -0.826
2001 09 – Current: -2.670
2002 09 – Current: -3.312
2003 09 – Current: -4.742
2004 09 – Current: -6.999
2005 09 – Current: -10.545
2006 09 – Current: -20.843

Clearly, the shorter terms are much more variable, but they are provided here for illustration.

TROPICAL SLOPES, presented as rate of warming per Century, in degrees Celsius:
1979 01 – Current: 1.534
1983 09 – Current: 2.095
1988 09 – Current: 2.095
1993 09 – Current: 0.596
1998 09 – Current: 1.741
1999 09 – Current: 0.914
2000 09 – Current: -2.306
2001 09 – Current: -5.508
2002 09 – Current: -7.961
2003 09 – Current: -9.578
2004 09 – Current: -14.859
2005 09 – Current: -16.988
2006 09 – Current: -38.525

NORTHERN HEMPISPHERE EXCLUDING TROPICS, presented as rate of warming per Century, in degrees Celsius:
1979 01 – Current: 2.894
1983 09 – Current: 3.322
1988 09 – Current: 3.261
1993 09 – Current: 2.832
1998 09 – Current: 1.088
1999 09 – Current: 1.932
2000 09 – Current: 2.060
2001 09 – Current: 1.228
2002 09 – Current: 1.801
2003 09 – Current: -0.622
2004 09 – Current: 0.245
2005 09 – Current: -5.069
2006 09 – Current: -9.470

SOUTHERN HEMISPHERE EXCLUDING TROPICS, presented as rate of warming per Century, in degrees Celsius:
1979 01 – Current: 0.577
1983 09 – Current: 0.730
1988 09 – Current: 0.557
1993 09 – Current: 0.434
1998 09 – Current: -0.445
1999 09 – Current: -0.613
2000 09 – Current: -2.223
2001 09 – Current: -3.596
2002 09 – Current: -3.466
2003 09 – Current: -3.621
2004 09 – Current: -5.755
2005 09 – Current: -9.021
2006 09 – Current: -12.787

ARCTIC SLOPES, presented as rate of warming per Century, in degrees Celsius:
1979 01 – Current: 4.332
1983 09 – Current: 5.129
1988 09 – Current: 6.705
1993 09 – Current: 6.280
1998 09 – Current: 5.641
1999 09 – Current: 5.396
2000 09 – Current: 3.477
2001 09 – Current: 1.426
2002 09 – Current: -3.362
2003 09 – Current: -3.217
2004 09 – Current: -5.465
2005 09 – Current: -20.225
2006 09 – Current: -33.563

ANTARCTIC SLOPES, presented as rate of warming per Century, in degrees Celsius:
1979 01 – Current: -1.380
1983 09 – Current: -1.096
1988 09 – Current: -1.905
1993 09 – Current: -0.942
1998 09 – Current: 2.770
1999 09 – Current: 1.225
2000 09 – Current: -2.427
2001 09 – Current: -3.356
2002 09 – Current: -5.094
2003 09 – Current: -3.051
2004 09 – Current: -10.757
2005 09 – Current: -16.362
2006 09 – Current: -17.937

The reader can see that every single region of the globe has a short-term cooling trend, and ever-decreasing trend lines starting around 15 years ago. The Antarctic is the only region to have a cooling trend over the length of the data set of nearly 30 years. One would never have guessed that based on reports of the melting ice shelf in Antarctica. The couple trend periods showing a positive trend have more to do with deep negative anomalies in those periods than an increasing temperature in recent years. In fact, recent years show a significant decline.

Every region of the globe shows a very steep short-term cooling pattern. This is even true in the Arctic. This may seem counter-intuitive, given the reports of lower ice mass over the last couple of years. It is not. The data clearly shows that the Arctic region has indeed warmed significantly over the last 30 years. A positive trend line is in place with as short a trend line as the last seven years. Such a long period of significant trending will not be offset by a recent decline. While anomalies have always fluctuated quite a bit, the increased consistency of positive anomalies (only 2 negatives since May 2002) mean that there is a net ice melt relative to average. While there is now a declining trend, the decline has its starting point with higher anomalies, and the current values are still positive. August rebounded with a fairly high anomaly (0.935) but 2008 so far has included five anomalies under 0.4. The last time this occurred in an eight-month period was the 8-month period ending December 2000. So, should the current trends (and by “trends” I mean the trend of lowering slopes as much as I mean the actual linear trend) continue, it seems that every region of the globe is pointing to cooler temperatures, including the Arctic. It would seem a decent bet that we are at a low point in expected ice-melt, unless the current trend reverses itself quickly.

This is a real quick review. It does not look at the changing 5-year or 10-year slopes, for example, and instead compares the slopes of differing lenghts. But I thought it to be an interesting exercise, so I thought I’d share the results.

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6 Responses to “September 2008 Update on Global Temperature – RSS, Part 2”

  1. Jeff Id said

    It seems like the solar cycle might be driving things more than science realized. Like you said, we’ll find out soon.

    I have dug deeper into paleoclimatology recently and have discovered that a statistically invalid method is being used to recreate past temperature variations. I thought you might be interested so I posted it here.

    http://noconsensus.wordpress.com/2008/09/07/global-warming-cookin-the-books/

    I would like to provide a link to your blog from my front page if you don’t mind. I think it would help if more people realized what you are doing.

  2. Diatribical Idiot said

    Thanks, Jeff. By all means, you may provide a link. I have checked your blog occasionally, as well, and would be happy to reciprocate.

  3. John A. Jauregui said

    1. I just returned from visiting Yellowstone and was struck by the devastation of the 1988 fires, which were preceeded by acute drought and record setting dry lightening. I began to wonder what solar activity occured leading up the 1988 fire storms. Solar cycle 22 started just a couple of years before that summer of drought and dry lightening. Check this out. Relative to other cycles, that solar cycle had 1) a very fast rise time – 2.8 years, 2) a very short cycle length – 9.7 years, 3) a high minimum sun spot number – 12.3, and 4) a high maximum sun spot number – 158.5
    more:
    “Cycle 22 certainly provided us with many highlights. Early in the cycle the smoothed sunspot number (determined by the number of sunspots visible on the sun and used as the traditional measure of the cycle) climbed rapidly; in fact more rapidly than for any previously recorded cycle. This caused many to predict that it would eclipse Cycle 19 (peak sunspot number of 201) as the highest cycle on record. This was not to be as the sunspot number ceased climbing in early 1989 and reached a maximum in July of that year. Whilst not of record amplitude, Cycle 22 still rated as 4th of the recorded cycles and continued the run of recent large solar cycles (Cycles 18, 19 and 21 were all exceptional!). A very notable feature of Cycle 22 was that it had the shortest rise from minimum to maximum of any recorded cycle.”
    Material Prepared by Richard Thompson. © Copyright IPS – Radio and Space Services.

  4. Stephen Wilde said

    Interesting that current cooling seems to be faster than the earlier warming.

    My various aricles at this link are of relevance for anyone interested:

    http://co2sceptics.com/news.php?tag=stephen+wilde

  5. Diatribical Idiot said

    Well, I have not isolated the rate of warming versus cooling in like periods of time, so we need to be careful about that. Keep in mind that the trend periods differ above. In order to get a proer perspective on rate of warming versus cooling we need to compare the same trend periods. I may do that by region for RSS next month if I have the time to take a look at that.

    For now, all the above shows is that the recent periods are cooling, even if the long-term trend value is still positive.

    I have bookmarked your link. I will check it out when I ahve time.

  6. cpria said

    hey thats a very good colection of info
    thanx

    priya
    http://www.nayaorkut.com

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