Posts Tagged ‘JPL’

Increase as Alleged Evidence of Downward Trend

Sunday, 14 June 2009
From Ideas, the 'blog of David D. Friedman:
Global Sea-ice, Deceptive Reporting, and Truthful Lies, 12 May 2009:

The latest Arctic sea ice data from NASA and the National Snow and Ice Data Center show that the decade-long trend of shrinking sea ice cover is continuing.

That statement, from the JPL, is dated April 2009. The actual data for northern hemisphere sea ice, measured as the deviation from its 1978-2000 mean, are shown below. The source is The Cryosphere Today, a web site of the Polar Research Group, Department of Atmosphere Sciences, University of Illinois at Urbana-Champaign, not a site devoted to critics of global warming. […]

Looking at the graph, the pattern is pretty clear. For about ten years, from 1997 to late 2007, the area of sea ice was decreasing. That trend then reversed, and the area has now been increasing for more than a year. […].

Sea Ice II: Reading Graphs, 13 May 2009:

On the other hand, poking around the same source, I found the graph for March, which provides at least a little support for the JPL comment I have been attacking, which was published in April. It shows March sea ice rising a lot for two years, but falling a little in the most recent year. To describe that as "continues to shrink" strikes me as clearly misleading, but it's an exaggeration to describe it as a flat lie.

Arctic Sea Ice Briefly Continued, 11 June:

[…] I emailed someone at NASA. […] Eventually he conceded that he was a media person, not a scientist, sent my question off to a scientist at the National Snow and Ice Data Center, and sent me the response.


I got back an evasive answer that came down to (not a quote) the long term trend is down, so objecting that JPL says the current data shows that trend continuing when it doesn't is merely a technical semantic objection.