Friday, May 08, 2009

Updated: NSIDC keeps banging the global warming drum

(Updated with the first chart, below, plus the half-wise verbiage of the opening paragraphs).
My erstwhile Antipodean shadow PKD has brought to my attention the June 2009 examples of the NSIDC's editorials, entitled "Melt Season Gains Momentum". His series of observations in his unique style would have been in the comments section at the bottom had I not clumsilty toasted them as I tried to update this posting.

Any one of us can be accused of cherry picking data, I am sure (even you, PKD!), so in the spirit of cherry picking let me just use the NSIDC's words and illustration, and add that May's ice extent using NSIDC data looks to be about the same as 1990 and is higher than all but four of the past 19 years. If this is a trend, I think we can live with it. NSIDC helpfully plots the downward trend from 1979, a year whose only significance is that satellite data became available, then goes on to say:

May 2009 compared to past Mays

Compared to previous Mays, ice extent in May 2009 is about average. Over the last four years, May ice extent has increased.


Here is the original blog posting from a month ago:

Give the National Snow and Ice Data Center full marks for consistency. But not for objectivity, at least not for objectively presenting their own data.


Take their May 4 2009 update of sea ice extent. The chart shows 2009 ice extent approaching the average for the period 1979-2000, which NSIDC uses as a consistent benchmark. The start of the period corresponds with the beginning of satellite measurement of ice extent. The accompanying summary states:
Arctic sea ice extent declined quite slowly in April; as a result, total ice extent is now close to the mean extent for the reference period (1979 to 2000). The thin spring ice cover nevertheless remains vulnerable to summer melt.
So don't stop worrying about global warming just yet, dear reader, because this ice could melt! Could it melt more readily than spring ice from other years? Yes, NSIDC declared a month ago:
the melt season has begun with a substantial amount of thin first-year ice, which is vulnerable to summer melt.
If temperatures remain below average (a condition which the NSIDC has finally acknowledged) then somehow the thin first-year ice may survive and become second-year ice, with any luck less "vulnerable to summer melt". But again, don't count on it, according to the NSIDC
...conditions may not always favor the survival of second-year and older ice. Each winter, winds and ocean currents move some sea ice out of the Arctic ocean.
Reading this, one would think that once there was a patch of open water the whole place turns liquid faster than you can say "Save us, Al Gore!" This is consistent with climate modelers' worldviews that climate feedbacks are positive and once a change has been set in motion there is no stopping it.

Think about that.

In geologic time frames our plucky blue planet has been brass monkey cold, and stinking hot, and every temperature in between. If the feedbacks were positive, once we started heading towards hot we would just keep going until we made ashes of ourselves. We would not BE here if climate feedbacks were positive.

Back to the NSIDC and its little report. Recall in the opening quote that they call 1979-2000 their "reference period". This is nice and neutral. If the same organization referred to a "long term decline" in their same article, how would you think this related to the reference period?

Below is the chart that covers the putative long term decline. The astute reader will note that while it comes from the same organization, the data and trend line extend into 2009. The reader would then wonder why the last eight full years are not included in the reference data, as they would most certainly confirm that ice extent is above overall average levels calculated from all data at hand. From the chart, ice extent appears higher than any April in the last decade.

The informed reader would also observe that the beginning of the period of satellite observations coincides with the end of the cold period that began in 1940 and covered almost 4 decades during which CO2 levels steadily climbed while temperatures dropped, but that is a topic for another day. It is no wonder that ice extent started high and dropped for a while.
Trends are not destiny. Ocean temperatures and atmospheric temperatures have both signalled that the warming trends of the NSIDC reference period have reversed and heat energy is being lost from the earth and its atmosphere, not accumulating as many have been led to believe.

There is more ice now than there has been in a decade. Don't be surprised by this. And consider the possibility that there will be even more ice next year and next decade as solar activity, the Pacific Decadal Oscillation and heaven knows what other mechanisms exert their normal will on us.

Then consider whether a colder planet is such a welcome prospect. I can imagine a time within ten years when we are struggling to feed our population and someone will suggest increasing CO2 emissions to enhance crop yields and maybe warm the place up a bit.

10 comments:

JR said...

Say, that blue line looks like it could even exceed the 79-00 average this year. Not that that is necessarily a good thing, as you point out:

"I can imagine a time within ten years when we are struggling to feed our population and someone will suggest increasing CO2 emissions to enhance crop yields and maybe warm the place up a bit."

Of course the ones that will suggest increasing CO2 are the ones that now think CO2 is the answer to all climate questions.

Ie, when the only tool in your box is a hammer, everything looks like a nail.

Halfwise said...

I have more faith in CO2 as a growth enhancer than as an agent of climate change. So in a perfect world ten years from now everyone will know that CO2 is good for plants and irrelevant to weather. And those companies that used CO2 in enhanced oil recovery will be paid to bring that CO2 back to the surface and vent it, yielding a smidgen of a return, finally, to those misguided fools who believed the market would reward them for building carbon sequestration infrastructure.

We have all the carbon sequestration capability we will ever need. It is called, generically, flora.

PKD said...

Heh. Don't tell me you still haven't learnt to distinguish one months weather from climate Half? Dear oh dear. I suppose I could mention that Marchs ice level NSIDC reported as the 4th lowest on record.

Don't you think one months slow start to Winter should be treated as such. One months weather?

Halfwise said...

Welcome back PKD. I thought this posting might get a response out of you.

Weather is just weather, of course, especially when it is inconveniently cold. A new record high temperature or low ice extent gets headlines.

Enjoy the skiing in Australia. I hear it is 5 weeks early this year. But that is, of course, just weather.

PKD said...

The snows all melted now I'm afraid while Vic enjoys one of its warmest Mays ever..

http://www.mthotham.com.au/today/snowcams/basin.htm

And it looks like the same is happening up in the Arctic with the ice level now closer to the record low than the climatic average...

http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

But I'll try not to confuse May weather with the climate and leave it at that hey? :)

Halfwise said...

PKD,
As you wish. Spring is late here and we broke a 50 year old weather record for cold temperatures. But it is just weather.

Where we differ, perhaps, is that I would not be so quick to declare anything about ice extent based on NSIDC's charts.

You can see that NSIDC has once again admitted to data problems and has removed its faulty chart from the public domain. http://www.nsidc.org/arcticseaicenews/index.html

I posted concerns about NSIDC's data quality last year; turns out my concerns were well-founded.

As a group NSIDC seems mightily self-assured with their conclusions, which (one would think) must occasionally trouble them when their data proves to be rubbish.

But I am old-fashioned that way.

PKD said...

Where we differ, perhaps, is that I would not be so quick to declare anything about ice extent based on NSIDC's charts. Ummm, wern't YOU the one flashing up the NSIDC graph in this very post when it was sohwing near average ice extent????

I think, when you choose to be, you can be very quick Half!

As a group NSIDC seems mightily self-assured with their conclusions, which (one would think) must occasionally trouble them when their data proves to be rubbish.Hmmm, I still think I'd gve them th ebenefit of the doubt than your gospel of denialism somehow!

Halfwise said...

Clever fellow, PKD.

NSIDC equipment and data problems as admitted so far don't fabricate ice, they ignore existing ice. All the errors are in the direction of understating reality.

Wouldn't you be just a teensy bit uneasy about the veracity of their "all-time record low" measurement in 2007?

Perhaps not. Just file it with all the other selective information you use.

By the way, speaking of gospels, which of the prophecies of the AGW congregation have come true so far?

PKD said...

Wouldn't you be just a teensy bit uneasy about the veracity of their "all-time record low" measurement in 2007? NOpe not at all.

I'm quite satisfied by NSIDC's explanation of the original problem with Satellite 15. And given the number of other denialists (Watts up with that to name one) who like to go over NSIDC data with a one-way comb, I'm
pretty certain they would have found something compelling by now about the 2007 record low data - if it really was in error.

Perhaps not. Just file it with all the other selective information you use.I'm sure you've forgotten more than I'll ever know about that particular technique Half!

By the way, speaking of gospels, which of the prophecies of the AGW congregation have come true so far?How about the 18000 year-old Chacaltaya glacier Half?

http://news.bbc.co.uk/1/hi/world/americas/8046540.stm

Being 18000 years old it obviously survived the medieval warm period, but not the warm period we now have. Predicted by AGW - and happened.

But heck,I'm sure you'll fall back to your old denialist meme of 'But you can't *prove* that it was AGW, therefore it MUST be something else!!!'.

Despite the fact that with the current evidence available, the best theory that fits the facts (accoriding to the principles of Ockram's razor) is AGW. Don't try and tell me that theres a , simpler, better supported, natural cycle explanation. Because there simply isn't!

PKD said...

Oooooh, don't look now Half,the ice extent is almost as low as the record low year of 2007!

http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

Gosh, that must be conclusive proof of AGW!!!!!