Where Did All the Ice Go? A Closer Look at the 2012 Melting Season

By Malte Humpert The 2012 melting season is in full swing and as of August 14 ice extent continues to track below the level for same date during the record melt year of 2007. This year's ice extent may be on track to reach a new record low in September. The graph below shows ice extent on August 14 for the 1980s, 1990s, 2000s, and 2002-2012.

According to Mark Serreze, director of the National Snow and Ice Data Center (NSIDC), ice loss is on pace to set a new record this year. Data sets by the NSIDC and the Japan Aerospace Exploration Agency (JAXA) show ice extent at 4.9 million square kilometers (August 13) and 5.02 million square kilometer (August 15), about 450,000 square kilometers below the 2007 record low for this date. The University of Bremen, whose data do not take into account ice along a 30km coastal zone, already sees ice extent below the all-time record low of 2007.

The interactive graph below place ice loss into a historical context and displays ice extent (at least 15% ice coverage) for the 1980s, 1990s, 2000s and 2007-2012. The graph is based on data by JAXA which can be found here.

A closer look at ice extent over the past month/14 days reveals how decline has accelerated since August 5 when a low pressure system entered the Arctic Ocean. The most rapid melt was observed on August 5-8 when ice extent dropped by more than 500,000 square kilometers.

The rate of decline between July 15 and August 14 reached 34.59%. In comparison during the 1980s and 90s ice extent decreased by only 20% in that 30 day period. During the record year of 2007 ice extent shrank by 30% between those two dates.

In addition to ice extent, ice volume is an important indicator. Volume relates to both ice thickness and extent and is therefore more directly tied to the long-term trends of climate change and less susceptible to particular weather patterns, i.e. storms or shift in winds that can affect ice extent. Ice volume on July 31, 2012, the last day for which PIOMAS data by the Polar Science Center at the University of Washington is available, stood at 5,770 cubic kilometers, compared to 12,433 cubic kilometers during the 2000s and 6,494 cubic kilometers in 2011.

The interactive graph below depicts ice volume for the 1980s, 1990s, 200s and 2007-2012. The graph is based on data by PIOMAS. Ice volume has declined dramatically over the past decade. The 2011 minimum ice volume was more than 50 percent below the minimum ice volume of 2005. Even in comparison to the record low ice extent year of 2007, ice volume decreased by almost 40 percent. The ice extent in 2007 and 2011 was roughly the same with 4.3 and 4.61 million square km, while ice volume decreased from 6.53 to 4.2 thousand cubic km showing how ice volume is decreasing at a much more rapid pace than ice extent. The ice volume for July 31, 2012 was roughly 10% below the value for the same day in 2011. A new study by UK scientists confirms that ice volume is declining at a remarkable rate of up to 900 cubic kilometers per year since 2004.

The rate of ice volume decline for the month of July reached a new record at 47%. This compares to 33% during the 2000s.

The final graph displays ice volume and ice extent for July 31 for the 1980s, 1990s, 2000s and 2002-2012 and shows how much faster ice volume is declining in comparison to ice extent. Whatever ice remained at the end of the summer 2011 was on average ~60% thinner than the ice during the 2000s.

* no data available for 2002 ice exent

[1] Chart based on data from Japan Aerospace Exploration Agency (JAXA) Sea Ice extent Data through the IARC-JAXA Information System (IJIS). Data accessed on 07/30/2012 at http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

[2] Charts based on data from PIOMAS Daily Ice Volume Data. Schweiger, A. 2011. Arctic Sea Ice Volume Anomaly, Version 2. Seattle, WA: Polar Science Center, Applied Physics Laboratory, University of Washington. Data set accessed on 12/20/2011 at http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/.

Where Did All the Ice Go? The Media's Coverage of the Greenland Melt Event

By Malte Humpert Earlier this week the National Aeronautics and Space Administration (NASA) released a press statement describing an unusual melt event in Greenland, where, within a 4-day span, 97 percent of the island's surface ice thawed. NASA’s press release, titled "Satellites see Unprecedented Greenland Ice Sheet Melt", quickly sent national and international media outlets into overdrive covering this "unprecedented" melt event. Except, NASA botched the title of its press release and inaccurately described the melt event as “unprecedented”. According to the release similar melt events can be expected to occur every 150 years and the last recorded event happened in 1889. This would make the recent event unusual but far from unprecedented. 

At that point, however, there was no stopping the media avalanche of inaccurate headlines and coverage, which largely failed to provide a nuanced and reasoned account of the important event in Greenland. Instead one could read sensationalist headlines describing how Greenland's ice cover is melting away (The Independent),  Greenland Goes Green: Ice Sheet Melted in Four Days (PBS), Greenland's Ice Sheet Melts At Abnormal Blazing Speed (NPR), Greenland loses 97% of surface ice layer (The Examiner), The big thaw: Greenland ice cover is melting away  (The Independent), Greenland's Ice Sheet Melts at Fast and Furious Pace (VoA), Greenland's ice sheet melted at unprecedented rate during July (The Guardian), Greenland's ice sheet is melting fast (The Guardian). 

Incorrect. The Greenland ice sheet, which is up to 3000+ meters thick, is not "melting away", did not "melt in four days", it is not "melting fast", and Greenland did not "lose 97% of its surface ice layer". Instead Greenland surface ice experienced thawing or melting across 97% of its area, most of which quickly refroze, especially at higher elevations. Only near the coast did some melt water drain into the ocean.

Most articles also exaggerated the importance of the melt event on global sea levels by explaining how sea levels would rise by up to 7.2 meters if the ice sheet were to melt. Here one example from The Independent: "The vast ice sheet of Greenland, which holds enough water to raise global sea levels by 7.2 metres, underwent a remarkable transformation for a few days this month when scientists observed an unprecedented melting of its frozen surface."

Yes, the Greenland ice sheet is experiencing a significant amount of melting and up to 1/5th of global sea level rise can be attributed to it, but creating a connection between short term thawing of surface ice, which is related to a meteorological anomaly known as a heat dome, and the much larger ongoing climate change-related melting of the ice sheet is a misrepresentation of the events. 

Unfortunately, as result of the kind of reporting Andrew Revkin described as “hyperventilating coverage”, the potential significance of the melt event was lost in most accounts. Accurate and nuanced reporting was far and few between. Here a few that got it right. 

In his article for Climate Central Andrew Freeman asks "But what does this event mean in the bigger picture of ice melt and sea level rise, and what led to it in the first place?"

Ker Than, writing for National Geographic News, also provides an accurate analysis writing that "It may be tempting to link the event to global warming, but scientists say such melts might occur every 150 years." 

PBS's Margaret Warner conducted an interview with Thomas Wagner, NASA Program Scientist for the cryosphere, which provides more insight into the matter as well. Still, PBS managed to botch its headline, writing Greenland Goes Green: Ice Sheet Melted in Four Days. 

Here an excerpt of the interview:

MARGARET WARNER: Now, what explains [the melt]? 

THOMAS WAGNER: [...] Well, the simplest explanation is this, is we had some pockets of warm air really form around Greenland that literally washed up over the entire ice sheet. And a lot of that is related. If you look at -- there are some indices people use to describe the state of the atmosphere. One of them is the North Atlantic oscillation. And this year, that happened to have a really strong high-pressure system formed over Iceland that allowed this warm air sit around and move over Greenland. 

MARGARET WARNER: So, you're basically talking about the weather? 

THOMAS WAGNER: Yes, and that is one way to think about it. Climate is sort of long-term weather. But short term, you can get extreme variations. And we're seeing an extreme variation in Greenland.

MARGARET WARNER: So, you're saying you can't really attribute this to climate change? 

THOMAS WAGNER: No. And that's one of the things. We spent a long time trying to word the document that we put out describing it. And we said, look, there is evidence that this has happened before. Now, that doesn't mean -- we really don't know the explanation for this one. If it happens again, if it starts to happen repeatedly, then we have an indication that there might be a real shift going on in the Arctic system there. 

A lot of media accounts also referenced the calving of Greenland's Peterman Glacier as another example of the unusual events that occur in the region. Most articles, however, failed to explain that the two are separate events and are not related.

The sheer number of headlinesexaggerating the importance of the event and the misinterpretation of its meaning is staggering. Such reporting provides a welcome opportunity for climate change skeptics and those questioning the soundness of climate science to plant the seed of doubt in the minds of the public. Part of the effort to implement lasting change capable of addressing the climate challenge needs to be the realization that exaggerations and the magnification of "dramatic" and "unprecedented" climate events may sell newspapers, but it also reduces the public’s ability to discern truly important climate events from mere meteorological events and thus diminishes the public’s willingness to be part of the solution to climate change.