Tag Archives: NSIDC

The United States’ National Snow and Ice Data Center

60 Per Cent of Nothing?

Our title today is an allusion to Bill Bruford’s “Five Percent For Nothing”, from the 1971 album “Fragile” by Yes. Here’s what the cover looks like:

Fragile cover art, by Roger Dean (image Wikipedia)

Them:

A chilly Arctic summer has left nearly a million more square miles of ocean covered with ice than at the same time last year – an increase of 60 per cent.

Us:

According to the NSIDC once again the numbers look like this:

NSIDC daily Arctic sea ice extent chart, highlighting September 7th 2013
NSIDC daily Arctic sea ice extent chart, highlighting September 7th 2013

The sums are obviously rather tricky, so we’ve enlisted the aid of a spreadsheet. Here’s what it reveals to us:

Metric Date 2012 2013 Increase
NSIDC Daily Extent (million km²) Day 249 3.558 5.236 47.2%
NSIDC Daily Extent (million km²) Sep 8th 3.523 5.179 47.0%
NSIDC Daily Extent (million km²) Aug 27th 3.94 5.632 42.9%
NSIDC Daily Extent (million km²) Aug 15th 4.845 6.159 27.1%
NSIDC Monthly Extent (million km²) August 4.71 6.09 29.3%

Verdict:

Whichever way you look at things, on a “same time last year” basis at least, the magic number of 60% seems to be out of reach. Whatever the arithmetic David Rose actually performed, whether mentally or on his pocket calculator, it would appear not to involve comparing like with like. We have asked David and the Mail on a number of occasions what numbers he started from and what calculations he performed. We have received no answers as yet.

Getting back to our title, when you start to look at Arctic sea ice volume instead of extent, 160% of almost nothing is still almost nothing:

Video courtesy of Andy Lee Robinson

Small print: We have yet to double check all the numbers in our simple spreadsheet. The NSIDC web site is still down today.

A Million Square Miles?

Let’s start at the very beginning. A very good place to start!

Them:

A chilly Arctic summer has left nearly a million more square miles of ocean covered with ice than at the same time last year – an increase of 60 per cent.

Us:

NSIDC Arctic Sea Ice News report for August 2012
NSIDC Arctic Sea Ice News report for August 2013

Verdict:

The Mail et. al. say “Nearly a million square miles”. When the floods in Boulder have receded the NSIDC will once again say “Just over half a million square miles”. Is that discrepancy sufficient to satisfy the Press Complaints Commission’s definition of “inaccurate, misleading or distorted information”?