August 2008 Update on Global Temperature – GISS
Posted by The Diatribe Guy on August 11, 2008
After the satellite data emerged a couple tenths of a degree above June’s anomaly, logic dictated that GISS should come in about the same. But logic doesn’t always follow with GISS because of the smoothing they do to the data. However, it looks like this month’s figures are surprising in that they are not surprising. The GISS anomaly is 51, versus the June anomaly of 27. That is an almost identical increase in anomaly to the satellite data.
Where the disagreement lies between GISS and the satellite data is in a comparison between the July 2007 anomaly and the July 2008 anomaly. While the satellite data shows a couple tenths drop from 2007, the GISS anomaly is nearly identical to last year’s anomaly of 53. Despite the jump, it is the fourth consecutive month at an anomaly below the previous year’s average, and the 11th of the last 12 – the lone exception being March’s number (60 vs. 59).
The average anomaly of the last 12 months has dropped to 42.1. That is the lowest 12-month average since the year ending October 2001 (41.9). Just as a note, last year’s August anomaly was 56, and August 2008 has started off looking cooler, according to the climate maps at the NOAA site, so it is likely that the average will lower next month again. However, the anomaly would need to be around 30 next month in order to meet the average of the previous earlier period ending September 2001 (39.8). Model predicted anomalies look to be between 40 and 50, preliminarily.
As usual, I start by presenting the overall trend:
The current anomaly did not extend the cooling trend back further on the front end at all. It only added the current data point to the period extending back to January 2001. The chart is as follows:
While this anomaly slows down the cooling trends we’ve been seeing, it still has steepened the 60-month slope, from -0.167 to -0.179.
We can see the changing 60-month slope trend here:
Though difficult to see on the far right side of this chart, the current negative slope is now at a level not seen since the early 1990s.
All other charts using GISS data show warming trend values of varying degrees. All of these trends are decreasing over time, indicating a slowing down of the warming trend. However, the trend line is positive. Also, the different cycles for the other trend lengths are interesting to look at, in that they spend most of their time above zero. What follows is a number of charts the reader may find interesting. My apologies for those with bandwidth issues.