How Fast is Arctic Sea Ice Declining? « The Air Vent

In summary, the following major points are highlighted:

1. Reconstructions of sea ice extent show no obvious decline until the advent of the satellite.
2. The claim that Arctic sea ice extent has been declining since 1953 is unjustified since there was no significant decline until 1979 when it exceeded 1 standard deviation below the 1953 to 1978 mean.
3. The satellite sensors drift, and as has been aptly displayed by SSM/I recently, there is at least one failure mode that results in underestimation of the sea ice extent.
4. The proclaimed unprecedented Arctic sea ice melt of 2007 does not appear particularly unusual and a similar but much more severe episode occurred in 1995, although at that time the measurements showed a higher starting level.
5. Presently, based upon the reportedly “most accurate” satellite data from AMSR-E (IRAC JAXA), Arctic sea ice extent is increasing at an accelerating rate.
6. Significant differences in winter ice extent are observed between NASA team SSM/I and AMSR-E IRAC JAXA during the overlapping period that might be explained by differing algorithms.
7. NASA team SSM/I shows a decline in extent relative to AMSR-E IRAC JAXA that might account for a substantial proportion of the apparent Arctic sea ice loss since the start of the satellite surveys.

Jonathan Drake 16/3/2009
Questioning Climate

Climate change: If we now have both SUVs and droughts, can we safely conclude that the SUVs CAUSED the droughts?

I am in Australia visiting my sister and her family, and the effect of climate change is evident all around. In Bendigo, Victoria, where she lives, there has been a full-on drought for over a decade. When I first visited over 20 years ago, Victoria was as green as South East England. Now, it is mostly yellow, and some bits of the countryside are beginning to fade to greyness. And yet Australian employers are still holding out against firm action on climate change.

Severe Ancient Droughts: A Warning to California - The New York Times

BEGINNING about 1,100 years ago, what is now California baked in two droughts, the first lasting 220 years and the second 140 years. Each was much more intense than the mere six-year dry spells that afflict modern California from time to time, new studies of past climates show. The findings suggest, in fact, that relatively wet periods like the 20th century have been the exception rather than the rule in California for at least the last 3,500 years, and that mega-droughts are likely to recur.