I sent some notes via Twitter yesterday and today to veterinarian turned NASA science writer Maria-Jose Vinas (who wrote yesterday’s self contradicting piece from NASA on Greenland) and AP’s Seth Borenstein about his article proclaiming the “sudden massive melt” in Greenland, citing Keegan et al. (2011):
From NEEM (a station with lower elevation than the Summit station)”
“A core from the CO2 firn-air sampling site at NEEM was retrieved in July 2009, and the physical properties of the firn have been analyzed. In the 81m of analyzed firn core, two regions containing ice layers were identified at depths of 29m and 46m. Isotopic analysis provides a depth-age scale that dates these layers to be from 1935 and 1879, respectively. These years were in the two warmest decades of the instrumental temperature record for Greenland.”
Viewing that image of “massive melt”, it looks like a Clara Peller moment for Seth. Hey Seth, where’s the beef?
The real meat is in the data, as Dr. Pielke writes:
source of image: Greenland Summit Station – the plot is of temperatures at the top of the Greenland icecap for the last 30 days.
The news headline, in particular, is an example of media hype. There was no “massive melt“. The term “massive” implies that the melt involved large masses of the Greenland icecap. They could have written “Sudden Extensive, Short-Term Surface Melting On the Greenland Icecap“, but instead chose to overstate what is a short-term weather event. Melting of surface ice occurs in Greenland whenever there are relatively warm surface air temperatures, as shown in the plot from Summit Station at the top of this post, and sunny skies, as reported by Thomas Mote in Seth’s article. Almost anytime, sublimation (direct transfer from ice to water vapor) occurs.
I noted a similar graph in my story yesterday. There may have been a brief few days of melt, but it appears to be over:
As Keegan et al. (2011) tells us, just because we have a shiny new satellite camera, doesn’t mean we are photographing “unprecedented events”. It is mind blowing that NASA would allow this self contradictory piece in the first place, and then let it go uncorrected after being notified that there’s no unprecedented event at all, and their own article citing Keegan et al says so!
The issue is with ascribing short term observations in nature to a long term problem. Our satellite record is very short, 30 years or less, yet when you go back and look at ice core data as NASA did, and at the anecdotal evidence of history, you find these events have happened before. It’s somewhat like the rush to blame severe weather and drought on global warming, yet when you look into the past, you find precedence for what is being described today as “unprecedented”. The belief that almost any aberration in weather and climate today can be attributed to global warming is pure folly, and tends to be rooted in our newly acquired ability to monitor the planet with millions of cameras in the hands of the public, and new instruments in the hands of the scientists.
(Note: I’ve covered the reporting bias related to the rise of technology in detail here: Why it seems that severe weather is “getting worse” when the data shows otherwise – a historical perspective )
Without looking to the past, which is much harder work than looking at the glitzy insta-photos from satellites, you really can’t say that events on the planet today are “unprecedented”.
A good example of historical precedence of melting in the Arctic is this article from 1922 in the WaPo:
Here is the text of the Washington Post (Associated Press) article:
The Arctic ocean is warming up, icebergs are growing scarcer and in some places the seals are finding the water too hot, according to a report to the Commerce Department yesterday from Consul Ifft, at Bergen, Norway.
Reports from fishermen, seal hunters and explorers, he declared, all point to a radical change in climate conditions and hitherto unheard-of temperatures in the Arctic zone. Exploration expeditions report that scarcely any ice has been met with as far north as 81 degrees 29 minutes. Soundings to a depth of 3,100 meters showed the gulf stream still very warm.
Great masses of ice have been replaced by moraines of earth and stones, the report continued, while at many points well known glaciers have entirely disappeared. Very few seals and no white fish are found in the eastern Arctic, while vast shoals of herring and smelts, which have never before ventured so far north, are being encountered in the old seal fishing grounds.
Another good example is the excitement over the “derecho” thunderstorm that flattened parts of Washington DC and knocked out power recently. Many have tried to link that event to global warming, but when you do the slightest cursory review of history, you discover that it is a climatologically common event, first described in the American Meteorological Journal in 1888 and by the records kept by the NOAA storm prediction center, a 1 every 4 years event for Washington DC:
Indeed, where’s the beef?
UPDATE: Andrew Revkin at NYT’s Dot Earth got a response from NASA and agrees this is a mess, writing in “Unprecedented’ Greenland Surface Melt – Every 150 Years?”
The flow of news releases and background science content from NASA is generally excellent, but the space agency badly blew it earlier this week with this headline, which has now reverberated around the Web: “Satellites See Unprecedented Greenland Ice Sheet Surface Melt.”
He adds this note from NASA, also citing Keegan et al. (2011):
Updated | Lora Koenig of NASA just sent this note providing the reference underlying her comment about past summer melting episodes at the summit (the spot on the giant ice sheet least vulnerable to melting):
The study I am citing is Alley and Anandakrishnan, 1995, “Variations in melt-layer frequency in the GISP2 ice core: implications for Holocene summer temperatures in central Greenland” published in the Annals of Glaciology for establishing the long-term frequency of melt events at Summit , Greenland. And Clausen et al., 1988 Glaciological Investigations in the Crete area, Central Greenland: A search for a new deep-drilling site also published in Annals of Glaciology for an early reference to the 1889 melt event though as mentioned in the press release Kaitlin Keegan and her advisor Mary Albert at Dartmouth University have more recent research on this event and please contact them for additional specific information.
My comment shows that melt events have occurred at Summit in the past and I have quoted the longest-term average frequency of ~150 years (exactly 153 from the paper) over the past 10,000. Since this is an ice core record that frequency is for the location of Summit only. The frequency ranges from ~80 to 250 years over different sections of the GISP2 ice core, please see the paper for specifics.
UPDATE2: I loved Revkin’s skewering of Joe Romm on his Tumblr blog. Revkin writes:
Joe Romm in full thought-police mode, labeling NASA glaciologist’s statement of scientific fact and uncertainty on Greenland surface melt episode “scientific reticence.” This even though Romm excerpts a line explaining that such events are etched in Greenland’s ice-core record roughly every 150 years:
“Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time,” says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data. “But if we continue to observe melting events like this in upcoming years, it will be worrisome.”
That statement is a classic example of what James Hansen called “scientific reticence.”