Sunday, February 15, 2009

Arctic Ice Update

Remember all that fuss in late 2007 about the supposedly melting Arctic ice? And how enviros downplayed it when the ice returned last year? Well Jeff of The Air Vent on Watts Up With That? investigated more carefully and found that 2007 was not a significantly unusual melting year:
This graph is a derivative of the ice area plot. The maximum peaks and valleys represent the maximum rates of change in 30 day periods through the ice record.

source: Watts Up With That?

Looking at this plot of the 30 day slopes of actual NASA gridded data, the maximum ice melt rate occurs in 1999 and in 2004 not in 2007. Surprisingly the maximum ice growth rates occur in 2007 and 2008, I don’t remember those headlines for some reason. Don’t forget when looking at the 2008 - 09 peak, the data is preliminary and hasn’t been through the same processing as the other data. From looking at the unprocessed data I doubt it will change much.

Certainly the 30 year arctic trend in ice area is downward, even the most committed global warming scientist has to admit this happens regularly in climate along with regular 30 year uptrends. The questions are, did we cause it or not, and was CO2 the instigating factor. The rapid recovery of ice levels has to have some meaning regarding the severity of the problem. This goes directly in the face of accelerated global warming and the doom and gloom scenarios promoted by our politicians and polyscienticians.

Why are my conclusions different from the news reported records? I think it’s likely due to the fact that the scientists used the monthly data which is processed using a weighted filter of the daily data that incorporates a longer time frame than a single month. This means their use of the monthly data to establish a monthly trend was in error and the real record down trends were actually set in 1999, 2003 and 1984. While the record uptrends were in 2007, 2008 and 1996.

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