More Antarctic melting threats
Richard Treadgold | September 1, 2012
A five-year study just published says methane hydrates buried under kilometres of Antarctic ice and sediment could accelerate global warming if released into the atmosphere. This has given the warmists much grist for their mills of alarm.
The paper, Potential methane reservoirs beneath Antarctica, published on 30 August as a letter in Nature, is behind a paywall, so I’ve only seen the abstract and Supplementary Information (pdf).
The paper contains some interesting information. The sediments are in surprisingly deep basins – down to 10 km or even 14 km in rifts (measured from the earth surface, not the top of the ice), although most are between 0.3 km and 3 km deep. That’s a lot of silt. The amount of overlying ice is similar, from 1 km to 3.5 km. That must all melt before the sediment has any hope of warming enough to release the methane clathrates. Chance would be a fine thing.
The NZ Herald quotes the scientific team: “Scientists have found the Antarctic ice sheet could be a major hidden source of methane…” Notice the moderate tone and complete absence of certainty. But then the reporter wrongly adds:
… with vast amounts of the potent greenhouse gas being released into the atmosphere as chunks of the sheet collapse into the ocean.
What? The present tense? Do reporters learn the differences between tenses any more? It’s not only misleading, it’s unscientific; not only alarmist, but exaggerated; it’s not only wrong, but it’s fabricated.
What’s the truth? The study concludes the possible existence of a very large quantity of methane in relatively shallow sediments overlain by several kilometres of ice which stands an extraordinarily small chance of melting within several thousand years and releasing the methane into the atmosphere, where it would almost definitely cause warming. But after that the story gets twisted beyond recognition.
Because no methane is “being released” into the atmosphere from deep under the Antarctic ice sheets. Neither are “chunks of the sheet [collapsing] into the ocean.” Since the ice sheet ranges well over 1500 km from the coast, the chance of chunks of it falling into the sea runs from remote to nil. Shame on the Herald; this is alarmist twaddle at its worst from the singularly uninformed Jamie Morton.
The Herald gets Dr James Renwick, Kiwi high priest of global warming, (no longer at NIWA, but now at Victoria University) to first intone the obvious to please the converted:
“If a lot of methane did suddenly get released into the atmosphere, it would have a large effect.”
He omits to mention that estimates of the “disintegration” of the WAIS range from 1000 to 10,000 years. That would affect sea levels immediately as it occurred, but entail a possibly tedious wait for we insignificant humans anxiously waiting to know if methane clathrates exist under the ice and sediment and their effect on the climate. Then, how much is there and how long will it take to melt after it’s exposed?
While we’re worrying about the sudden methane, the Herald provides a smooth misdirection by bringing up the Arctic. No doubt the audience supposes the Arctic conditions are the same in the Antarctic, though they are not. Also, see how James the consummate magician magically extracts two separate occurrences out of a single event. The Herald continues:
Separate findings at the opposite end of the globe have signalled warming is happening at an alarmingly fast rate.
New analysis found Arctic sea ice had melted to the lowest extent seen in records that began more than 30 years ago, breaking the previous record low observed five years ago.
So the first event is the minimum summer extent of Arctic sea ice, reported last week as exceeding the record low of 2007. But whether a record was set depends on which data source you consult, as WUWT explains.
The Herald reminds us that accurate satellite ice records only began 30 years ago – this is a very short observation of polar ice that first emerged about 5 million years1 ago and it’s too early to conclude that we’re causing any problems for it. The ice was broken up by an unseasonal storm in early August, making it more vulnerable to melting in the summer temperatures.
Back to the Herald:
Dr Renwick described a rapid melt rate at the start of the month, where an area nearly the size of New Zealand disappeared each day, as “just jaw-dropping”.
“This event unfolding in the Arctic Ocean right now should be a wake-up call to governments worldwide that climate change is a serious threat, and it is not [a] distant menace, it is on our doorstep today.”
This is James’s second event. I couldn’t remember hearing about this “warming” at the time and it puzzled me. After some searching, I wondered if Dr Renwick might be talking about the early August storm that dispersed the sea ice?
But that would mean he was describing a basically wind-driven dispersion as warming. Would he do that? I think he must have. I’d hate to think he just made it up, but I’d be very interested to see a reference to the unusual early August “warming.” Like, say, a temperature record.
But that’s how he gets two events from one, two stories from a single narrative, a spontaneous set of twins. First the record summer minimum sea ice extent, second the rapid melt rate at the start of the month – “jaw-dropping” it was. But they were the same thing. I await his reference.
Now back to reality. So we’re in no doubt about it, NASA published a feature on 9 August titled Summer Storm Spins Over Arctic, which describes what happened.
Arctic storms such as this one can have a large impact on the sea ice, causing it to melt rapidly through many mechanisms, such as tearing off large swaths [sic] of ice and pushing them to warmer sites, churning the ice and making it slushier, or lifting warmer waters from the depths of the Arctic Ocean.
It’s clear that atmospheric temperature alone was not responsible for the large reduction in the ice cover and the apparent record minimum – if it was a record.
Renwick got the last word with a piece of naked activism:
“This event unfolding in the Arctic Ocean right now should be a wake-up call to governments worldwide that climate change is a serious threat, and it is not [a] distant menace, it is on our doorstep today.”
One might have imagined that moving to academia might have moderated any urge to zealotry, but not in this case.
He says global warming is on our doorstep so there must have been substantial changes recorded in New Zealand’s recent weather. Perhaps he would describe them. He claims that global warming is a serious threat, so maybe he can explain why our temperature, according to NIWA’s 7 Station Series, shows no significant rise for 60 years?
Pish-tush. No global warming for 15 years and still they claim that warming is a serious threat.
I suppose it must be a threat, because it’s certainly not real.
1 The history of the earth’s surface temperature during the past 100 million years. Savin, S. M. Annual review of earth and planetary sciences. Volume 5. (A77-38469 17-46) Palo Alto, Calif., Annual Reviews, Inc., 1977, p. 319-355. DOI: 10.1146/annurev.ea.05.050177.001535
Retrieved from http://adsabs.harvard.edu/full/1977AREPS…5..319S 1 Sep 2012.
