March 2008 Global Warming Update

[Diatribical Idiot]

The global temps are out, according to the NASA source that Paul likes to use, and so I am using it also. It is located at http://data.giss.nasa.gov/gistemp/tabledata/GLB.Ts.txt.

I have updated my trend analysis on the numbers to include these results, for any interested in scoring at home.

The February anomaly was 31 (where 1 = 0.01 degrees Celsius and the anomaly is the deviation for the 1950-1980 time period, which is about 14 degrees Celsius).

This is the same anomaly as January 2008, which at the time was the lowest such anomaly since July 2004. The anomaly's positive number says it's still above the base period average, and the base period is relatively close to overall average for the entire period from 1880-current.

The 2-month average anomaly of 31 is the lowest 2-month anomaly average since October-November 2000 (average was 29). The latest 12-month average anomaly of 62.7 is still relatively high by historical standards, but has been moving down over the last couple years. The last time it was at least this cool on a 12-month rolling average basis is the April 2004 - March 2005 period, where the average was 61.4.

This is the lowest February-specific anomaly since 1994. It was the 28th warmest February on record.

With this additional data point, we can map the most recent non-warming/cooling trend from Ocober 2001 - Current. Stated another way, applying a simple linear trend to the data, there has been no warming, and possible cooling, since October 2001. This encompasses 77 data points of anomalies. While this certainly could indicate a peak, or a downward trend, there have been similar periods in the past where we've seen this occur. The most recent 77 data-point period of cooling occurred from April 1990 - August 1996. We saw another spurt in the interim before we saw the more recent flattening.

As previously noted, I have tracked a 120 data point slope of the anomalies (rolling) to see what is occurring as far as a speeding-up/slowing-down of the rate of warming. There has been a consistent decline in the 120 data point slope over the last 70+ slope calculations. The trend in the change of the slope is now -.002774 degrees Celsius per month. The current 120 point slope is positive, but getting less positive by that amount.

Last month, I presented my Required/Predicted Anomalies by month. These would be the anomalies required for that month to hit the trend line in order to continue the trend of decreased rate of warming. My required anomaly for February 2008 was 53.35. The actual anomaly of 31, then, comes in quite a bit lower, and the impact of this was to make the slope of the trend line slightly more negative. As of 2007 year-end, the trend analysis implied a 2008 predicted anomaly of 44.8. The updated analysis after January lowered that to 44.6. Remaining months were last predicted to be: March 47.4; April 46.0; May 37.5; June 31.6; July 24.7; August 38.8; September 65.7; October 55.8; November 59.8; December 43.7.

Because February came in so low, the required anomaly for March to hit the trendline has increased quite a bit. However, because the slope is now more negative, the succeeding anomalies are slightly reduced after that. The "trend line anomalies" going forward are:

March 68.1
April 45.9
May 37.4
June 31.6
July 24.6
August 38.8
September 65.6
October 55.7
November 59.8
December 43.6

Using actual January/February anomalies and the trend line anomalies, the updated 2008 average anomaly would be 44.4. The last time we has a 12-month average anomaly at least that low was April 2000-March 2001 (43.5). The last Calendar year with an average that low was 2000 (41.8)

[General Apathy]

So now we get to worry about an ice age?

[The President]

I agree that it was colder this February compared with recent years.

[General Apathy]

Hey President, when temperatures start going down, what way will you invent to ***** about it?

[Samir]

Does this really matter? The Gamma Ray is coming! The Gamma Ray is coming!

[tenthring]

We still get to throw corn in our gas tanks either way, right?

[Paul Brand]

La Nina is still holding at farily strong levels (similar to 2000, actually, which was slightly cooler than 2008). La Nina is expected to die steadily through the year (according to NOAA), though projections have a rather high amount of uncertainty.

[Drinks]

In other words, the climate will be warmer except when it's colder.

[Paul Brand]

Originally Posted by Diatribical Idiot

Using actual January/February anomalies and the trend line anomalies, the updated 2008 average anomaly would be 44.4. The last time we has a 12-month average anomaly at least that low was April 2000-March 2001 (43.5). The last Calendar year with an average that low was 2000 (41.8)

I think my latest model projection was about 0.55-0.57C (not considering 2008 actuals). My model is at home, so I can't remember the exact number off the top. If I had a monthly model, it probably would have came up with something like 0.50C for Jan/Feb considering La Nina is weighted towards the winter months. So if I make an adjustment for actuals, I would lower the above by 0.03C.

My model attributes a lot of the year to year variability to ocean cycles. I don't have a full understanding of how much seasonality interacts with ENSO. I've often read that winters are the most affected. I will have to spend more time with the data to see if the ENSO data has different reletive impacts by season.

[Aaron Brachowitz]

Hey, when I go to church I don't want charts and graphs proving to me that Jesus was or was not the Son of God.