NASA Speaks on 2009

I’d been watching the GISS page closely, to no avail, but it turns out that the annual summation for 2009 global temperatures was posted on James Hansen’s Columbia page.

(Click on the graph for a better resolution in the Columbia document.)

2009 is the second warmest on record, “but it is so close to 1998, 2002, 2003, 2006, and 2007 that we must declare these years as being in a virtual tie as the second warmest year,” says Dr  Hansen. 2009 is probably the warmest among those years, and 2006 is probably the coolest.

2009, especially the spring and summer, was quite chilly in my area, so this is a perfect example of the difference between regional and global temperature. Global temperature reflects the amount of infrared radiation in the atmosphere; regional temperature reflects how that energy is distributed.

NCDC’s preliminary calculations, however, show 2009 as the fifth warmest on record. What are the reasons for this discrepancy? Do they monitor Arctic temperatures differently than NASA, like the British Met Office does?

Hopefully, this will be the end of “global warming stopped in 1998” comments. But maybe the usual suspects will keep saying it and hope nobody notices, or say “global warming stopped in 2005” instead.


11 thoughts on “NASA Speaks on 2009

  1. How can 2009 be the second second warmest on record? I looked here:

    I put the years in order and find this:

    GISS TOP-10 UAH TOP-10
    1. 2005 77 1. 1998 52
    2. 2007 72 2. 2005 34
    3. 2009 71 3. 2002 32
    4. 1998 70 4. 2007 28
    5. 2002 67 5. 2003 28
    6. 2003 66 6. 2006 26
    7. 2006 64 7. 2009 26
    8. 2004 59 8. 2001 20
    9. 2001 55 9. 2004 20
    10. 2008 54 10. 1991 12

    There’s also temperatures from UAH:

    [If I know James Hansen, he’ll have computer code/more explanation coming soon. Read over his 2009 document carefully, too – it might answer your question. -Kate]

  2. “Hopefully, this will be the end of “global warming stopped in 1998″ comments”

    Don’t hold your breath. This is merely the latest in a long line of debunkings of the particular talking point.

    The fact that the “AGW stopped in 1998” claim is still made is a perfect example of the non-scientific position of the deniers.

  3. “How can 2009 be the second second warmest on record? I looked here:

    Because it’s a ‘land only’ (ie met stations) file.

    Look here: (land+ocean)

    [Ah, that makes sense. The oceans were especially warm this year – June-August was the warmest on record. Taking that out of the equation would certainly change the final result. -Kate]

  4. Kaj,

    You’ve posted a link to the GISTEMP “global-mean monthly, annual and seasonal dTs based on met.station data”. However, Hansen’s figure says it depicts the “land-ocean temperature index”, which is here:

    The difference is that the met station data excludes sea surface temperatures, an obvious problem for a global average for a planet whose surface is 70% water. You can see this in the corresponding two graphs (met station and land-ocean, respectively), which have opposite rankings of 2007 and 2009:

    However, this doesn’t quite resolve the discrepancy. According to the land-ocean index I linked above, 2009 and 2007 are exactly tied at anomalies of 0.57 C (Jan-Dec). Most likely 2009 pulls ahead in the third decimal place which is not listed. The two points are extremely close in the graph and, as Hansen said, they are statistically tied.

  5. Kaj Luukko,

    The reason for the conflict between the various data sets you refer to is that the three are measuring three seperate things. You are compairing apples and oranges. If you look at the header for the GISS webpage you will find that it says “sources: GHCN meteorological stations only.” GHCN stands for Global Historical Climatology Network, which is a data set maintained in part by the National Climatic Data Center (NCDC) that consists of land based Meteorological Station measurements which include temperature measures. The GHCN does not include any observations made at sea, as such the global average given is not an average for the whole globe but is instead the total average of land measurements.

    The UAH measures are derived from satelite data for the troposphere.

    The GISS Global Land-Ocean Temperature Index is intended to be what it says, the average surface temperature for the entire planet.

    All of these things are usefull. All are measures of different things.

    All of this is to the best of my knowledge. A description and some links are given at:

    The first link is of course more authoritative.

  6. The focus of attack is now on ‘the temperature record is fraudulent” – so denialists can claim anything they want and if it doesn’t fit the reported facts they simply say “the scientists fiddled with that data”. Obviously, for a certain group of people, it is easier to believe a gaggle of bloggers and right wing commentators than it is to believe actual scientists…

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