‘Tis the season of resurrections. And right on cue, science PR is working overtime to bring the polar-ice soap opera back from the dead.

Following a disappointing summer of 2008, in which the ‘worst ever’ Arctic ice scenarios prophesied at the start of the year failed to materialise, there was the danger that viewers would start channel-hopping. Something had to be done.

To get things rolling, the scriptwriters at the National Snow and Ice Data Center (NSIDC) have introduced a couple of new characters for the 2009 season – winter maximum sea ice extent and ice thickness, both of which made an appearance in the first episode aired this week by the BBC:

The Arctic sea-ice reached its maximum extent this year on 28 February, slightly earlier than usual, and remained roughly constant through March.

Averaged over March, the sea-ice covered 15.16 million sq km (5.85 million sq miles).

By comparison, this was 590,000 sq km (228,000 sq miles) below the average for the years 1979 to 2000, and 730,000 sq km (282,000 sq miles) above the record low of 2006.

and

“Thickness is important, especially in the winter, because it is the best overall indicator of the health of the ice cover,” said NSIDC scientist Walt Meier.

“As the ice cover in the Arctic grows thinner, it grows more vulnerable to melting in the summer.”

In the 1980s, thick multi-year ice made up 30-40% of the cover, the scientists say.

The summer minimum area is changing much faster than the winter maxima, shrinking by about 0.7% per year. Last year UK researchers showed that the ice has also markedly thinned in recent years.

The BBC story followed a series of press releases that the NSIDC started pumping out to journalists just as soon as the melt season had begun. This is what has popped up in our inbox this month so far:

April 1, 2009
Sea ice cover over the Arctic Ocean typically reaches its maximum geographic extent and thickness just as spring begins in the Northern Hemisphere. However, the winter maximum extent has been lower during the last six winters than at any other time during thirty years of satellite records. Scientists have also observed that ice thickness and age are changing. They will present their analyses of Arctic ice cover for the 2008 to 2009 winter season at the briefing.

6 April 2009
MEDIA ADVISORY: Update on Arctic Sea Ice Conditions
In conjunction with a NASA/NSIDC media teleconference today, NSIDC has issued an update to Arctic Sea Ice News & Analysis describing winter sea ice conditions in the Arctic Ocean. To read the full analysis from NSIDC scientists, see http://nsidc.org/arcticseaicenews/2009/040609.html
Supporting information for the media briefing is available on the NASA Web site at: http://www.nasa.gov/topics/earth/features/seaice_status09.html. Audio of the teleconference will be streamed live on the NASA Web site at http://www.nasa.gov/newsaudio.

April 8, 2009
Media Advisory: Ice Bridge Supporting Wilkins Ice Shelf Collapses
An ice bridge connecting the Wilkins Ice Shelf on the Antarctic Peninsula to Charcot Island has disintegrated. The event continues a series of breakups that began in March 2008 on the ice shelf, and highlights the effect that climate change is having on the region… [etc]

The press, of course, lap up these plot twists like there’s no tomorrow, using them to pack out column inches with stories about how there’s no tomorrow. Take the opening paragraph of the BBC piece:

Arctic ice reached a larger maximum area this winter than in the last few years, scientists say, but the long-term trend still shows it declining.

This is such an utter non-story – amounting to no more than ‘NSIDC have another year’s worth of winter Arctic ice data’ – that the only reason we can see for the BBC giving it the time of day is to guard against the possibility that people start filling their pretty heads with silly notions that the extent of summer Arctic sea ice varies from year to year, and that while it seems to have been reducing a bit over the last few decades, it hardly follows that it spells the end of the world as we know it.

We mentioned recently that climatological natural variation comes in two varieties. To repeat ourselves, there is the type that is ignored by ‘deniers’ asking awkward questions about recent temperature plateaus. And there’s the type that is to be disregarded for the sake of alarmist stories about single, aberrant weather events.

Both scientists and journalists are guilty of these double standards. And in the BBC piece, we have another prime example. While bending over backwards to stress that, due to natural variation, a single data point that is not as ominous as it could have been in an ideal world does not mean there’s nothing to worry about, the BBC is entirely reliant on ignoring that very same natural variation in order write something – anything – about the latest installment from the NSIDC. It regurgitates NSIDC graphs, complete with lines of best fit that reveal the underlying downward trend towards inevitable oblivion, without wondering why scientific predictions from the NSIDC and elsewhere about the future of Arctic ice are spread across a whole continent of ball parks each the size of Wales. (Estimates for the date of an ice-free Arctic summer – an arbitrary milestone that has nonetheless come to be understood as the signal hailing the Horsemen (Norsemen?) of the Arctic Apocalypse – range from 2008 to 2013, through 2030 to 2100 to some time in the next century, or some time after that.)

This NSIDC graph used by the BBC shows winter maximum sea ice extent:

Ignore natural variation, and what remains is a shallow downward trend that looks vaguely scary only because of the scale of the y axis. We’re just surprised that no one has thought to extrapolate it to come up with a date for when there’ll be no Arctic sea ice even in winter. (2320, by our reckoning. That’s got be worth a press release.)

Meanwhile, the x-axis comprises 30 years of satellite data, a period of time that barely even qualifies as a timescale over which changes in climate can be assessed with confidence. According to the UK Met Office:

The World Meteorological Organization (WMO) requires the calculation of averages for consecutive periods of 30 years, with the latest covering the 1961-1990 period. However, many WMO members, including the UK, update their averages at the completion of each decade. Thirty years was chosen as a period long enough to eliminate year-to-year variations.

The NSIDC, like the BBC, has its own love-hate relationship with natural variation. Last year, we quoted from a classic NSIDC presser in which, in a single short paragraph comprising three sentences, they managed to both sex up 2008 as a potential record-breaker and warn us off getting over-excited by a single year’s data:

Sea ice extent has fallen below the 2005 minimum, previously the second-lowest extent recorded since the dawn of the satellite era. We will know if the 2008 record will also fall in the next several weeks, when the melt season comes to a close. The bottom line, however, is that the strong negative trend in summertime ice extent characterizing the past decade continues.

The NSIDC is happy to provide a running commentary on the monthly ebbs and floes (ho ho) of ice behaviour, while simultaneously maintaining that only the long-term trend is important. It even goes as far as to provide daily pictorial updates of the state of the ice. As the link on the NSIDC homepage puts it:

Read year-round scientific analysis and see daily image updates of Arctic sea ice

We can certainly appreciate that updating the data set regularly is a great service for working scientists, but it is far less obvious how the pictures help anything. It’s a cheap exercise in outreach. Effectively, it just serves to turn esoteric research data into the subject of a salacious rolling news channel. It’s not as if NSIDC are not conscious of the problems involved in disseminating complex science to non-specialist audiences. When, last year, we asked the NSIDC’s Walt Meier why the center chose to present data showing only one of the two measures of Arctic ice cover that they collect (respectively known as ‘extent’ and ‘area’), when the presentation of both would perhaps reflect more realistically the complexity involved in taking such measurements (let alone using them to make predictions,), he told us:

When you’re talking to the public and the press and so forth […] adding ‘area’ into the discussion can cause confusion. So we’ve kept to ‘extent’ to keep things consistent in how we’re reporting things and reporting one parameter instead of two […] We’ve chosen to not include the ‘area’ [data], even though there are interesting things to say about it, just because, for a lot of people, it does tend to muddy the water.

We wonder what could muddy the water of 30-year trends more than making a pictorial feature of daily installments of ice behaviour.

To an extent, the NSIDC’s hand has been forced. The Arctic has proved such fertile ground for alarmist opportunists (especially when terrestrial and orbiting thermometers are failing to provide headlines) that the NSIDC’s little blue lines on graphs are no longer the only game in town. Last year, self-proclaimed Arctic ambassador Lewis Pugh hit the headlines when he set off to canoe to the North Pole to raise awareness of the shrinking summer ice, although he went rather quiet – as did the media – after he failed miserably in his mission, having been blocked by summer ice. The NSIDC is also facing hot competition from the British Catlin Arctic Survey, which employs good old-fashioned Arctic explorers to do, we are told, what satellites cannot, which is to measure the thickness of Arctic sea ice. That’s the same thickness of Arctic sea ice that NSIDC tells us, without qualification, that satellites tell us is declining. No doubt the current state of knowledge regarding ice thickness lies somewhere between the two contrasting pictures painted by NSIDC and Catlin. But that these organisations are prepared to paint such simplistic pictures to raise awareness of their respective missions should itself set alarm bells ringing.

Who knows what twists and turns the NSIDC’s little blue line(s) will take this year? But it will be well worth tuning in to find out. It’s set to be good viewing. And don’t forget the Antarctic, which is now starting to feature in NSIDC press releases again having waited patiently in the wings for several seasons. The Wilkins ice shelf in particular is showing signs of restlesseness, a sub-plot that will no doubt feature more prominently should the Arctic not come up with the goods again.

Finally, as in all the best soap operas, the BBC leaves us with a cliff-hanger, courtesy of NSIDC’s Walt Meier:

NSIDC researchers believe that a warm summer could see a major melt.
“We’re not set up well for summertime,” said Dr Meier. “We’re in a very precarious situation.”

Precarious situation indeed. And not only for the reasons that Meier had in mind. It’s not just Arctic sea ice that’s on the line, but the reputation of a scientific discipline that has got distracted by the need to save us all from our sins. Tune in for the next episode. There might be a crucifixion.