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East Antarctic glaciers could be much more vulnerable to climate change than previously thought.

The views expressed are those of the author and are not necessarily those of Scientific American.


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Glacier retreat (red) and advance (blue) in the East Antarctic from 1974-2010 (Image from Miles et al. Nature, 2013).

The warming, melting and potential contributions to sea level rise from glaciers in Greenland and West Antarctica in the face of climate change has long since been a serious concern. The behavior of the much larger East Antarctic ice sheet has been much more uncertain and until now has been thought to be relatively insensitive to climate change.

Now an important paper in Nature from Durham University and the University of Zurich has examined a large number of satellite observations of the East Antarctic ice sheet over the last forty years. The authors find that although there is considerable variability in individual glacier advance and retreat, there is a clear overall trend of advance and retreat that tracks well with warming and cooling periods between 1974 and 2010. Glacier movement is thus much more sensitive to climate trends than previously thought. The work casts serious doubt on reassurances about the stability of the East Antarctic ice sheet.

Three epochal patterns emerged from the analysis: 63 per cent of glaciers retreated from 1974 to 1990, 72 per cent advanced from 1990 to 2000, and 58 per cent advanced from 2000 to 2010. These results were consistent with warming and cooling. The effect was most significant along the western South Pacific Coast and was least along the Ross Sea Coast.

The study looked at a large data set of approximately 300 satellite images of glaciers from 1963-2010 to map the positions of 175 glaciers along 5400 km. The data set was thus quite comprehensive. The images showed variation in individual glacier movement that was linked to their width; large glaciers undergoing much more change than smaller ones. However the overall switch from advance to retreat was very highly significant and swamped this individual variability; for instance, between 1974-1990 the glaciers retreated at a median rate of -12.5 m/yr while they advanced at a median rate of 19.7 m/yr during 1990-2000, a change of about 375%.

These changes were consistent with a relatively warm period in the 70s and 80s and cooling in the 90s. The advance and retreat also seem to track well with more subtle changes; for instance while the planet warmed until 2005, there has been a cooling trend since 2005 which is reflected in the slowing down of the retreat. However the paper is careful not to directly connect the glacier change to air temperature, instead recognizing air temperatures as part of a more complex system – the Southern Annular Mode (SAM) which comprises not just the air but also other factors like wind-speed, the interplay between the ocean and the atmosphere and sea-ice concentration. It’s worth noting though that positive trends in the SAM have been linked to ozone depletion and increasing greenhouse gas concentrations over the last two decades, so the correlation with air temperatures might possibly be a good proxy.

In spite of this complexity, the three trends in glacier advance and retreat since the 70s explicitly stand out and are consistent with measures of warming and cooling since then. The study does make it clear that the East Antarctic glaciers, which were thought to be relatively impervious to climate change, are likely as or more sensitive to global warming and other climate change effects as the better understood West Antarctic and Greenland ice sheets. In one sense this finding is very significant since the East Antarctic ice sheet is much larger than its western counterpart; thus, whatever humans are doing to the climate is likely to have potentially huge impacts on the melting of this ice sheet and a corresponding change in sea levels. We are mucking around with these massive wonders of ice at our own peril.

Reference:Rapid, climate-driven changes in outlet glaciers on the Pacific coast of East Antarctica”, Miles, Stokes, Vieli and Cox, Nature, 2013, 500, p. 563-567

Ashutosh Jogalekar About the Author: Ashutosh (Ash) Jogalekar is a chemist interested in the history and philosophy of science. He considers science to be a seamless and all-encompassing part of the human experience. Follow on Twitter @curiouswavefn.

The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. M Tucker 5:57 pm 08/28/2013

    We have put at risk of terrible suffering not only the children alive today but future generations to come. The longer we delay serious action the more severe the suffering will be. As long as we depend on market forces or even the economic planning of state managed economies we will not see any change from the relentless acceleration of atmospheric greenhouse gasses.

    I cannot think of a better example than China. China does not have the regulatory requirements that the US does for building nuclear power plants. China is in the best position to invest only in nuclear and renewables but, because they do not see that an emergency exists, they continue to build what amounts to 3 coal plants per month.

    “According to a new WRI [World Resources Institute] analysis, more than half of China’s proposed coal-fired power plants are slated to be built in areas of high or extremely high water stress. If these plants are built, they could further strain already-scarce resources, threatening water security for China’s farms, other industries, and communities.

    As of July 2012, China’s government planned 363 coal-fired power plants for construction across China, with a combined generating capacity exceeding 557 gigawatts (for reference, installed capacity at the end of 2012 was 758 GW. This amounts to an almost 75 percent increase in coal-fired generating capacity. China already ranks as world’s largest coal consumer, accounting for almost 50 percent of global coal use. Using WRI’s Aqueduct Water Risk Atlas, we overlaid the locations of these proposed coal plants on our water stress maps for China. We found that 51 percent of China’s new coal-fired power plants would be built in areas of high or extremely high water stress.

    This finding is especially troubling because coal-related industries—mining production, coal-to-chemical, and power generation—are extremely water-intensive. Coal mines depend on water to extract, wash, and process the coal, while coal-burning power plants need water to create steam and cool generating systems. If all of the proposed plants are built, the coal industry – including mining, chemical production, and power generation – could withdraw as much as 10 billion cubic meters of water annually by 2015. That’s more than one-quarter of the water available for withdrawal every year from the Yellow River.”
    [from Bloomberg today "Fire and Water: China's Looming Coal Problem"]

    China is ignoring their water problem. China is playing games with its air pollution problem. China is ignoring the world GHG problem. Even if the US and the rest of the developed nations began to address climate change how in the world will we avoid severe suffering from a climate out of balance if China continues on this path?

    Where did I get the 3 coal plants per month reference? At Quartz, by Gwynn Guilford on 8/27/13 under China’s Transition in the menu bar.

    Link to this
  2. 2. sault 9:55 am 08/29/2013

    Ash,

    Thanks for highlighting this issue. However, I would caution against saying that “…while the planet warmed until 2005,there has been a cooling trend since 2005…”. 2010 is also tied for 2005 as the hottest year globally and it is impossible to state with any certainty that the Earth is cooling or warming given the data. In addition, 8 years is way too short a time to make any determination about warming or cooling trends since climate inertia, ENSO and other natural variability will tend to drown out the man-made climate warming signal over such short timescales.

    Regardless, over the latest period of supposed “cooling” , Antarctica still experienced accelerating ice mass loss:

    ” We use monthly measurements of time-variable gravity from the GRACE (Gravity Recovery and Climate Experiment) satellite gravity mission to determine the ice mass-loss for the Greenland and Antarctic Ice Sheets during the period between April 2002 and February 2009. We find that during this time period the mass loss of the ice sheets is not a constant, but accelerating with time, i.e., that the GRACE observations are better represented by a quadratic trend than by a linear one, implying that the ice sheets contribution to sea level becomes larger with time. In Greenland, the mass loss increased from 137 Gt/yr in 2002–2003 to 286 Gt/yr in 2007–2009, i.e., an acceleration of −30 ± 11 Gt/yr2 in 2002–2009. In Antarctica the mass loss increased from 104 Gt/yr in 2002–2006 to 246 Gt/yr in 2006–2009, i.e., an acceleration of −26 ± 14 Gt/yr2 in 2002–2009.”

    http://onlinelibrary.wiley.com/doi/10.1029/2009GL040222/abstract?systemMessage=Wiley+Online+Library+will+be+disrupted+on+31+August+from+10%3A00-12%3A00+BST+%2805%3A00-07%3A00+EDT%29+for+essential+maintenance&userIsAuthenticated=false&deniedAccessCustomisedMessage=

    Link to this
  3. 3. bgrnathan 10:38 am 08/29/2013

    GLOBAL WARMING MAY NOT BE MAN MADE

    Dr. Larry Vardiman (scientist and physicist) of the Institue for Creation Research says:

    “One possible scenario may be found in a recent series of articles by Henrik Svensmark and Nigel Marsh, cosmic ray specialists from Denmark, who have shown an indirect connection between galactic cosmic ray (GCR) intensity and global temperature.7,8,9 They are studying the influence of the Sun on the flow of GCR to Earth. The Sun’s changing sunspot activity influences the magnetosphere surrounding the Earth permitting more GCR to strike the Earth during high periods of activity.

    When the Sun is active, the intensity of GCR striking the Earth is increased, causing more ionization in the atmosphere, creating more carbon-14, and possibly creating more cloud condensation nuclei (CCN). This increase in CCN, in turn, appears to create more low-level clouds which cool the Earth. When the Sun is quiet the GCR intensity striking the Earth is reduced, allowing the Earth to warm. Svensmark and Marsh have shown a striking statistical correlation between sunspot activity and global cooling and warming over the past 1000 years.

    The recent rise in global temperature may partially be due to current low solar activity supplemented by a recent increase in carbon dioxide concentration measured at Mauna Loa. The connection which still needs further study is the production of CCN and clouds by GCR.”

    There is a good deal of science showing that global warming is not mad made. Yes, we still should have pollution controls, as we already do, but not to the extreme because it will unnecessarily hurt business.

    Visit my newest Internet site: THE SCIENCE SUPPORTING CREATION

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    Link to this
  4. 4. ReduceGHGs 10:51 am 08/29/2013

    Some of the comments overlook the fact that human-caused climate change is well established science. All the world’s respected scientific institutions that considered the issue concur.

    It is too late to stop significant melting and the inundation of low coastal areas around the world. We have changed the atmosphere’s composition and our societies’ foundations rest on burning fossil fuels for energy. It will take time to change. But we must change. Business as usual is not sustainable. It is dangerous, self-destructive, irrational, and immoral.

    Contact your representatives in Congress. Insist they work harder to reduce global emissions. If they drag their feet, confront them, then help elect more progressive candidates in the next election cycle. The health and safety of future generations is worth the effort.

    Link to this
  5. 5. Carlyle 10:01 pm 08/29/2013

    There are many mysteries yet to be uncovered in the field. One thing is clear. Antarctic sea ice continues to advance well into the fourth decade. Arctic sea loss this year is only a third as large as last year. Neither can be linked to CO2 emissions which continue to increase.

    Link to this
  6. 6. José 6:33 am 09/1/2013

    “East Antarctic glaciers could be much more vulnerable to climate change than previously thought.”

    I’d be interested to learn how vulnerable Antarctic glaciers were “previously thought” to be?

    Link to this
  7. 7. Dr. Strangelove 2:18 am 09/4/2013

    “whatever humans are doing to the climate is likely to have potentially huge impacts on the melting of this ice sheet and a corresponding change in sea levels. We are mucking around with these massive wonders of ice at our own peril.”

    Ash, this is contradictory to the rest of the article. East Antarctic glaciers have been advancing since 1990 so whatever humans are doing to the climate is not melting the ice and not contributing to rise in sea level. What is the peril in that?

    Link to this
  8. 8. ABlack 7:37 am 01/29/2014

    sadly the majority of people don’t seem to care about this issue.

    Logged in as : https://www.facebook.com/buysteroids

    Link to this

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