Friday, November 12, 2004

More Global Warming Junk

Arctic indigenous peoples urged the United States on Friday to join other nations in cutting greenhouse gas emissions to brake an accelerating thaw of the polar ice.

What do the scientific studies of artic ice show?

Johannessen et al. (1999) used surface-based measurements to derive variations in area-averaged Arctic sea-ice thickness from 1978 to 1991. They, too, detected a downward trend in this parameter. All of the drop occurred rather abruptly over a single period of not more than three years (1987/88-1990/91) .

Winsor (2001) based on a more extensive analysis concluded that "mean ice thickness has remained on a near-constant level around the North Pole from 1986 to 1997."

Holloway and Sou (2002) On the basis of a number of different data-fed model runs, they found that for the last half of the past century there had been no downward trend in artic ice thickness. They noted that year to year variablity of ice thickness can be large.

Polyakov et al. (2002) and Polyakov et al. (2003), reported that the available fast-ice records "do not show a significant trend."

Laxon et al. (2003) Using radar techniques over the largest areas surveyed up to now they saw high year to year variablity in artic ice mass not supportive of current ideas of global warming induced change.

Pfirman et al. (2004) analyzed Arctic sea-ice drift dynamics from 1979-1997, showed that ice was being pushed out of the artic into seas further south by higher winds in certain years, a phenomenon which probably best explains the high annual variablity of the artic ice mass. The life of sea ice in the artic can be as short as 3 years as ice pushed out is constantly being replaced. Thus, the whole system is highly dynamic and subject to variablity from a number of factors, including the winds and ocean currents during certain years.

It's the old story. High degrees of natural variablity in certain measurements are filtered through global warming groupthink to become evidence of impending doom, and anecdotes of eskimos falling through thin ice are made to trump carefully done scientific studies.