Tuesday, April 13, 2010

We have a record - hottest 12 months since modern record-keeping began in 1880

Via David Appell and this commenter, NASA records show the last 12 months, April 2009 to March 2010, to be the warmest 12 months since global records began, 130 years ago.

What is important about this record is how it fits a trend. It would be interesting but unimportant (kind of like the occasional record cold or snow we see in some locations are interesting but unimportant) except that it further confirms the long-running trend for warmth, and contradicts the denialist claims that temperatures have been cooling in recent years. I'm not sure if we need further confirmation of something like gravity, but it's been checked and it's still there. With Kerry and Graham set to unveil their new climate bill next week, I think it would be appropriate to make a big deal out of this.

The satellite sets don't yet show a record, but they measure slightly different things, and they're going up too. I wonder how long it will take people like Roy Spencer to continue reporting warming before they finally break down and admit what's happening. It would also be interesting to see what other surface record compilations give for their results on a running 12 month period.

UPDATE: Brad DeLong understands the value of emphasizing this record.


  1. Here is something: going off of the same NASA temperature anomaly records, since 1883, the earliest month in which a record 12 consecutive month temperature record was set without a later month of the same year breaking that record was April -- of 1901.

    A few minutes with Excel...

  2. Here is the spread sheet:


    It shows the monthly global temperature anomaly on the first sheet, the consecutive 12-month average global temperature anomaly on the next, then on the last sheet shows the values for those months where on a given month the consecutive 12-month average global temperature anomaly was an instrumental record compared to the instrumental record that preceded it.

    People can check the formula, or for that matter, download a copy of the the spreadsheet workbook.

