New paper finds Western Himalayan glaciers stable to increasing in size

A paper published today in The Cryosphere surveys all glaciers in the Karakoram region of the Western Himalayas and finds overall glacier ice mass is stable to increasing over the past 3 to 4 decades. The finding is in stark contrast to the IPCC's infamous & embarrassing false prediction [using fake data] that all Himalayan glaciers would disappear by 2035. The paper corroborates another recent paper finding most of the 2000 Himalayan glaciers are stable and in a steady state. 

According to the authors, "we conclude on a balanced/positive mass balance in the Karakoram since the 1980s or 1990s, or even earlier, induced by changing climatic conditions since the 1960s.", "Out of 1219 glaciers in the inventory, the vast majority [79%] showed stable terminus positions (969)" and "Glacier recession is found for only 8% of the glaciers in the inventory, indicating decreasing numbers since the beginning of the 21st century, whereas the number of advancing glaciers has increased since then."

Excerpt:

Conclusions and outlook 

The present study utilizes different remote sensing-based methods to generate an updated glacier inventory for the entire Karakoram region. It provides a new comprehensive dataset on the state of advancing, stable, and retreating glaciers, including the temporal and spatial variations of frontal positions between 1976 and 2012. Out of 1219 glaciers in the inventory, the vast majority [79%] showed stable terminus positions (969). These findings support the assumption of the anomalous behavior of glaciers in the Karakoram in comparison to adjacent mountain ranges, which indicate glacier recession and thinning (Bolch et al., 2012; Hewitt, 2005; Gardelle et al., 2013; Kääb et al., 2012; Scherler et al., 2011). Glacier recession is found for only 8% of the glaciers in the inventory, indicating decreasing numbers since the beginning of the 21st century, whereas the number of advancing glaciers has increased since then. Considering the advance of small glaciers with assumed short response times of about 10–20 years, we conclude on a balanced/positive mass balance in the Karakoram since the 1980s or 1990s, or even earlier, induced by changing climatic conditions since the 1960s (Archer and Fowler, 2004; Bocchiola and Diolaiuti, 2013; Williams and Ferrigno, 2010; Yao et al., 2012).

The Cryosphere, 8, 977-989, 2014 www.the-cryosphere.net/8/977/2014/ doi:10.5194/tc-8-977-2014 Glacier changes in the Karakoram region mapped by multimission satellite imagery

M. Rankl¹, C. Kienholz², and M. Braun^1
1Institute of Geography, University of Erlangen-Nuremberg, Wetterkreuz 15, 91058 Erlangen, Germany
²Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775-7320, USA
Positive glacier-mass balances in the Karakoram region during the last decade have fostered stable and advancing glacier termini positions, while glaciers in the adjacent mountain ranges have been affected by glacier recession and thinning. In addition to fluctuations induced solely by climate, the Karakoram is known for a large number of surge-type glaciers. The present study provides an updated and extended inventory on advancing, stable, retreating, and surge-type glaciers using Landsat imagery from 1976 to 2012. Out of 1219 glaciers the vast majority showed a stable terminus (969) during the observation period. Sixty-five glaciers advanced, 93 glaciers retreated, and 101 surge-type glaciers were identified, of which 10 are new observations. The dimensional and topographic characteristics of each glacier class were calculated and analyzed. Ninety percent of nonsurge-type glaciers are shorter than 10 km, whereas surge-type glaciers are, in general, longer. We report short response times of glaciers in the Karakoram and suggest a shift from negative to balanced/positive mass budgets in the 1980s or 1990s. Additionally, we present glacier surface velocities derived from different SAR (synthetic aperture radar) sensors and different years for a Karakoram-wide coverage. High-resolution SAR data enables the investigation of small and relatively fast-flowing glaciers (e.g., up to 1.8 m day⁻¹ during an active phase of a surge). The combination of multitemporal optical imagery and SAR-based surface velocities enables an improved, Karakoram-wide glacier inventory and hence, provides relevant new observational information on the current state of glaciers in the Karakoram.

New paper finds the majority of East Antarctic glaciers have advanced in size since 1990

A new paper published in Nature finds that a majority of the outlet glaciers along the East Antarctic ice sheet have advanced in size over the past 20 years from 1990 to 2010. According to the paper, "Despite large fluctuations between glaciers—linked to their size—three [significant] patterns emerged: 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." According to the authors, "In the 1970s and 80s, temperatures were rising and most glaciers retreated. During the 1990s, temperatures decreased and most glaciers advanced. And the 2000s saw temperatures increase and then decrease, leading to a more even mix of retreat and advance." "When it was warm and the sea-ice decreased, most glaciers retreated, but when it was cooler and the sea ice increased, the glaciers advanced." [Note: Antarctic sea ice is currently near record-high levels]

Excerpt from the paper:

Here we present multidecadal trends in the terminus position of 175 ocean-terminating outlet glaciers along 5,400 kilometres of the margin of the East Antarctic ice sheet, and reveal widespread and synchronous changes. Despite large fluctuations between glaciers—linked to their size—three epochal patterns emerged: 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.

East Antarctic Ice Sheet Could Be More Vulnerable to Climate Change Than Previously Thought

Aug. 28, 2013 — The world's largest ice sheet could be more vulnerable to the effects of climate change than previously thought, according to new research from Durham University.

A team from the Department of Geography used declassified spy satellite imagery to create the first long-term record of changes in the terminus of outlet glaciers -- where they meet the sea -- along 5,400km of the East Antarctic Ice Sheet's coastline. The imagery covered almost half a century from 1963 to 2012.

Using measurements from 175 glaciers, the researchers were able to show that the glaciers underwent rapid and synchronised periods of advance and retreat which coincided with cooling and warming.

The researchers said this suggested that large parts of the ice sheet, which reaches thicknesses of more than 4km, could be more susceptible to changes in air temperatures and sea-ice than was originally believed.

Current scientific opinion suggests that glaciers in East Antarctica are at less risk from climate change than areas such as Greenland or West Antarctica due to its extremely cold temperatures which can fall below minus 30°C at the coast, and much colder further inland.

But the Durham team said there was now an urgent need to understand the vulnerability of the East Antarctic Ice Sheet, which holds the vast majority of the world's ice and enough to raise global sea levels by over 50m.

Dr Chris Stokes, in Durham's Department of Geography, said: "We know that these large glaciers undergo cycles of advance and retreat that are triggered by large icebergs breaking off at the terminus, but this can happen independently from climate change.

"It was a big surprise therefore to see rapid and synchronous changes in advance and retreat, but it made perfect sense when we looked at the climate and sea-ice data.

"When it was warm and the sea-ice decreased, most glaciers retreated, but when it was cooler and the sea ice increased, the glaciers advanced. [Note: Antarctic sea ice is currently near record high levels]

"In many ways, these measurements of terminus change are like canaries in a mine -- they don't give us all the information we would like, but they are worth taking notice of."

The researchers found that despite large fluctuations in terminus positions between glaciers -- linked to their size -- three significant patterns emerged:

• In the 1970s and 80s, temperatures were rising and most glaciers retreated;
• During the 1990s, temperatures decreased and most glaciers advanced;
• And the 2000s saw temperatures increase and then decrease, leading to a more even mix of retreat and advance.

Trends in temperature and glacier change were statistically significant along the East Antarctic Ice Sheet's warmer Pacific Coast, but no significant changes were found along the much cooler Ross Sea Coast, which might be expected if climate is driving the changes, the Durham researchers said.

Dr Stokes said that the cause of the recent trends in air temperature and sea ice were difficult to unravel but were likely to reflect a combination of both natural variability and human impacts.

However, he added that the changes observed in glaciers in East Antarctica needed further investigation against the backdrop of likely increases in both atmospheric and ocean temperatures caused by climate change.

Dr Stokes said: "If the climate is going to warm in the future, our study shows that large parts of the margins of the East Antarctic Ice Sheet are vulnerable to the kinds of changes that are worrying us in Greenland and West Antarctica -- acceleration, thinning and retreat.

"When temperatures warm in the air or ocean, glaciers respond by retreating and this can have knock-on effects further inland, where more and more ice is drawn-down towards the coast.

"We need to monitor their behaviour more closely and maybe reassess our rather conservative predictions of future ice sheet dynamics in East Antarctica."

Journal Reference:
B. W. J. Miles, C. R. Stokes, A. Vieli, N. J. Cox. Rapid, climate-driven changes in outlet glaciers on the Pacific coast of East Antarctica. Nature, 2013; 500 (7464): 563 DOI:10.1038/nature12382

Himalayan glaciers not melting because of climate change, report finds

Himalayan glaciers are actually advancing rather than retreating, claims the first major study since a controversial UN report said they would be melted within quarter of a century.

The Telegraph 1/27/11


By Dean Nelson and Richard Alleyne

Researchers have discovered that contrary to popular belief half of the ice flows in the Karakoram range of the mountains are actually growing rather than shrinking.

The discovery adds a new twist to the row over whether global warming is causing the world's highest mountain range to lose its ice cover.

It further challenges claims made in a 2007 report by the UN's Intergovernmental Panel on Climate Change that the glaciers would be gone by 2035.

Although the head of the panel Dr Rajendra Pachauri later admitted the claim was an error gleaned from unchecked research, he maintained that global warming was melting the glaciers at "a rapid rate", threatening floods throughout north India.

The new study by scientists at the Universities of California and Potsdam has found that half of the glaciers in the Karakoram range, in the northwestern Himlaya, are in fact advancing and that global warming is not the deciding factor in whether a glacier survives or melts.

Dr Bodo Bookhagen, Dirk Scherler and Manfred Strecker studied 286 glaciers between the Hindu Kush on the Afghan-Pakistan border to Bhutan, taking in six areas.

Their report, published in the journal Nature Geoscience, found the key factor affecting their advance or retreat is the amount of debris – rocks and mud – strewn on their surface, not the general nature of climate change.

Glaciers surrounded by high mountains and covered with more than two centimetres of debris are protected from melting.

Debris-covered glaciers are common in the rugged central Himalaya, but they are almost absent in subdued landscapes on the Tibetan Plateau, where retreat rates are higher.

In contrast, more than 50 per cent of observed glaciers in the Karakoram region in the northwestern Himalaya are advancing or stable.

"Our study shows that there is no uniform response of Himalayan glaciers to climate change and highlights the importance of debris cover for understanding glacier retreat, an effect that has so far been neglected in predictions of future water availability or global sea level," the authors concluded.

Dr Bookhagen said their report had shown "there is no stereotypical Himalayan glacier" in contrast to the UN's climate change report which, he said, "lumps all Himalayan glaciers together."

Dr Pachauri, head of the Nobel prize-winning UN Intergovernmental Panel on Climate Change, has remained silent on the matter since he was forced to admit his report's claim that the Himalayan glaciers would melt by 2035 was an error and had not been sourced from a peer-reviewed scientific journal. It came from a World Wildlife Fund report.

He angered India's environment minister and the country's leading glaciologist when he attacked those who questioned his claim as purveyors of "voodoo science".

The environment Minister Jairam Ramesh had cited research indicating some Himalayan glaciers were advancing in the face of the UN's claim.


Abstract located here:
Spatially variable response of Himalayan glaciers to climate change affected by debris cover
Authors: Dirk Scherler, Bodo Bookhagen, Manfred R. Strecker

Nature Geoscience

Controversy about the current state and future evolution of Himalayan glaciers has been stirred up by erroneous statements in the fourth report by the Intergovernmental Panel on Climate Change1, 2. Variable retreat rates3, 4, 5, 6 and a paucity of glacial mass-balance data7, 8 make it difficult to develop a coherent picture of regional climate-change impacts in the region. Here, we report remotely-sensed frontal changes and surface velocities from glaciers in the greater Himalaya between 2000 and 2008 that provide evidence for strong spatial variations in glacier behaviour which are linked to topography and climate. More than 65% of the monsoon-influenced glaciers that we observed are retreating, but heavily debris-covered glaciers with stagnant low-gradient terminus regions typically have stable fronts. Debris-covered glaciers are common in the rugged central Himalaya, but they are almost absent in subdued landscapes on the Tibetan Plateau, where retreat rates are higher. In contrast, more than 50% of observed glaciers in the westerlies-influenced Karakoram region in the northwestern Himalaya are advancing or stable. Our study shows that there is no uniform response of Himalayan glaciers to climate change and highlights the importance of debris cover for understanding glacier retreat, an effect that has so far been neglected in predictions of future water availability9, 10 or global sea level11.

New paper finds glaciers have been melting naturally at the same rate since 1850, no acceleration predicted

A paper published today in The Cryosphere finds global glaciers melted at the same rate in the first half of the 20th century as in the second half. This implies no man-made influence on glacier melt, since the melting began naturally at the end of the Little Ice Age in 1850 with "safe" CO2 levels, and continued at the same rate throughout the 20th century with no acceleration. The authors predict glacier mass loss will continue at the same rate in the 21st century and have "relatively weak dependence" on future greenhouse gas emissions. 

Since glacier mass loss is the largest single cause of sea level rise, this explains why there has been no acceleration of sea level rise over the past 100-200 years and why sea level rise is also unlikely to accelerate in the 21st century. 

The lack of any acceleration in glacier mass loss and sea level rise in the 20th century despite an exponential rise in greenhouse gases proves that both of these processes are primarily natural and unrelated to CO2. During prior interglacials, most glaciers disappeared, as well as the entire ice sheet of Greenland and West Antarctica, all entirely natural and with "safe" levels of CO2. There is no evidence the current interglacial is any different. 

Excerpts:

Glaciers have lost a substantial fraction of their mass during
the past century (Cogley, 2009; Marzeion et al., 2012), with
the globally averaged mass balance turning negative probably
around 1850 (Leclercq et al., 2011).Within the 20th century,
mass loss of glaciers was likely the largest single cause
of sea level rise, followed by thermal expansion of the ocean,
mass loss of the Greenland and Antarctic ice sheets, and
changes in terrestrial water storage (Gregory et al., 2013).
Even though the rise of global mean air temperature accelerated
in the 20th century, the mass loss rate of glaciers during
the second half of the 20th century was not higher than
during the first half of the century (Leclercq et al., 2011;
Marzeion et al., 2012).

Observed sea level rise during the 20th century can only be
explained if the glaciers’ contribution did not develop in parallel
to global mean temperature, but was high already in the
first half of the 20th century (Gregory et al., 2013). Our result
that changes in glacier hypsometry play a significant role in
shaping the glaciers’ response to climate change, in particular
that loss of low-lying surface area (i.e., terminus retreat to
higher elevations) decreases the sensitivity is critical for explaining
the strong glacier-mass losses during the first half of
the 20th century.

Conclusions

We have used a model of glacier response to climate change
to quantify the equilibrium sensitivity of glaciers, and to distinguish
the respective contributions of temperature and precipitation
anomalies. Because of the geographic distribution
of glaciers, the temperature and precipitation change experienced
by glaciers is far greater than the global mean. Precipitation
anomalies projected for the future dampen the mass
loss of glaciers, but their effect is strongly limited by the increasing
temperatures, which increases the liquid fraction of
precipitation on the glaciers.

We find that glacier-mass loss during the 21st century is
to a significant degree a response to 20th century climate
change. This partly explains the relatively weak dependence
of 21st century mass loss on future greenhouse gas emissions.
A second reason is that the complete loss of individual
glaciers imposes a strong restriction to the rates of mass loss
in a warming climate. Results from methods not accounting
for finiteness of ice mass available for melting, for example,
by extrapolating current rates of mass loss, or even increases
of rates of mass loss (Meier et al., 2007), will therefore yield
substantial overestimates.

Thirdly, changes of glacier hypsometry reduce the response
of glaciers to warming, and need to be considered
in explaining the observed rates of mass loss during the 20th
century and the projected rates for the 21st century. Figure 9
summarizes our quantification of this effect. We find that the
retreat of glacier termini to higher altitudes is a strong negative
feedback, which is becoming weaker as more glaciers
disappear completely.

The Cryosphere, 8, 59-71, 2014 www.the-cryosphere.net/8/59/2014/ doi:10.5194/tc-8-59-2014

Feedbacks and mechanisms affecting the global sensitivity of glaciers to climate change
B. Marzeion¹, A. H. Jarosch², and J. M. Gregory^3
1Center of Climate and Cryopshere, Institute of Meteorology and Geophysics, University of Innsbruck, Austria
²Institute of Earth Sciences, University of Iceland, Reykjavík, Iceland
³NCAS-Climate, University of Reading, Reading, and Met Office Hadley Centre, Exeter, UK
Abstract. Mass loss by glaciers has been an important contributor to sea level rise in the past, and is projected to contribute a substantial fraction of total sea level rise during the 21st century. Here, we use a model of the world's glaciers to quantify equilibrium sensitivities of global glacier mass to climate change, and to investigate the role of changes in glacier hypsometry for long-term mass changes. We find that 21st century glacier-mass loss is largely governed by the glacier's response to 20th century climate change. This limits the influence of 21st century climate change on glacier-mass loss, and explains why there are relatively small differences in glacier-mass loss under greatly different scenarios of climate change. The projected future changes in both temperature and precipitation experienced by glaciers are amplified relative to the global average. The projected increase in precipitation partly compensates for the mass loss caused by warming, but this compensation is negligible at higher temperature anomalies since an increasing fraction of precipitation at the glacier sites is liquid. Loss of low-lying glacier area, and more importantly, eventual complete disappearance of glaciers, strongly limit the projected sea level contribution from glaciers in coming centuries. The adjustment of glacier hypsometry to changes in the forcing strongly reduces the rates of global glacier-mass loss caused by changes in global mean temperature compared to rates of mass loss when hypsometric changes are neglected. This result is a second reason for the relatively weak dependence of glacier-mass loss on future climate scenario, and helps explain why glacier-mass loss in the first half of the 20th century was of the same order of magnitude as in the second half of the 20th century, even though the rate of warming was considerably smaller.

Never mind: Scary videos of Glaciers Calving 'from AGW' just due to naturally soggy bottoms

One of the icons of global warming propaganda is the shots of glaciers calving into the sea, an entirely natural process which has been occurring for eons. Both Greenland and Antarctica are huge bowl shaped basins which buildup snow in the interior which turns into ice. The tremendous pressure of the increased ice in the basins causes the glaciers to slide toward the edges and squeeze out like toothpaste which we witness as glacier calving. This is explained in a geoscientist journal article here and by geologist Ian Plimer here. A new paper published in nature explains how these glaciers continuously slide from the interior to exterior of these basins without any influence from mankind.

Glaciers May Have Soggier Bottoms Than Thought
By Charles Q. Choi posted: 29 September 2010 01:08 pm ET



Drilling boreholes with a hot-water drill on Bench Glacier, Alaska.

Glaciers may seem to be all ice, but it turns out they can be soggy with water, a finding that should help researchers understand how glaciers slide toward the sea, and improve their predictions about rising sea levels in the face of climate change.

"Adding water to the base of glaciers and ice sheets can make them speed up," said glacialogist Joel Harper of the University of Montana at Missoula, who with his colleagues discovered an unexpected amount of water near the bottom of a glacier in Alaska.

Scientists had long known that water will pool in the crevasses at the bottom of a glacier, the huge cracks that extend upward into the ice from the bedrock. However, precisely how much water is in these "basal crevasses" was uncertain because it was hard to peer into these giant mounds of ice.

Now, after using radar and seismic imaging of Bench Glacier in southeastern Alaska, as well as by directly drilling into it, researchers learned that glaciers can possess extensive networks of interconnected, water-loaded basal crevasses.

Harper and his colleagues focused on the temperate valley glacier, about 4 miles (7 kilometers) long and up to 650 feet (200 meters) thick, located in the Chugach Mountains east of Anchorage. Their experiments discovered numerous water-filled basal crevasses that regularly extended as much as 260 feet (80 meters) up from the bedrock into the ice.

Based on their data, the researchers estimated that the basal crevasses in Bench Glacier hold enough water to cover the glacier's bed with water 4 inches deep (10 cm). Although that may not sound like much, even a roughly 1.5-inch (4-cm) increase in the amount of water caused by spring melting can trigger a fivefold increase in the sliding speed of the glacier, Harper explained.

Boring surprise

Harper and his colleagues actually discovered these crevasses by accident. They were originally investigating the pressure that water experiences under glaciers — this pressure and the sliding speed of glaciers can sometimes be closely tied. To observe the effects of the pressure, they aimed to melt holes in the glacier 590 feet (180 meters) deep, all the way down to the base , using jets of hot water to bore into the ice. When all the water from this drilling hit the water pooled under the glacier, they predicted, a big pressure spike would result and they could detect it at other boreholes, giving clues as to how water pressure under glaciers changes over time and space.

"Much to our surprise, the instruments showed a huge draining event long before the drill hole hit bottom," Harper recalled. "We lowered a video camera down the boreholes and found we had intersected a basal crevasse."

The researchers then began drilling to look for other water-filled crevasses and started imaging them with radar and seismic tools to learn more about them.

Glacier speed and sea level change

Given the discovery of numerous water-loaded crevasses in Bench Glacier, "there is reason to believe that they can sometimes exist in other glaciers, but now we need to figure out how common they are in other places," Harper said. "We are now drilling in Greenland."

A better understanding of how water flows under glaciers and influences their speed is key to improving our projections of sea level change, Harper said.

"One of the major barriers to generating reasonable projections of sea level rise is our limited understanding of how meltwater influences the sliding speed of glaciers and ice sheets," Harper explained. "Glacier speed influences sea level through calving of icebergs. Faster speeds result in more icebergs generated at the calving front."

The scientists detail their findings online today (Sept. 29) in the journal Nature.

Nature: New satellite study sparks fresh debate about the melting of Himalayan glaciers

Himalayan Glacier Data Shift To The Middle Ground

23 Aug 2012

Nature: New satellite study sparks fresh debate about the melting of Himalayan glaciers.

Satellites can be powerful tools to map complex changes across large, inaccessible areas — but only if researchers are able to interpret correctly what their measurements mean.

A 2010 study using measurements taken by the Gravity Recovery and Climate Experiment (GRACE) satellite reported that glaciers in the Himalayas and the Tibetan plateau were shedding roughly 50 gigatonnes of ice a year1. But these results were refuted two years later by another group that used the same data set but interpreted it to show that ice loss was only one tenth of that amount2.

Now a third study of Himalayan glaciers, using a different satellite called ICESat, indicates that these glaciers lost an average of 12 gigatonnes ice a year between 2003 and 20083. The work is published today in Nature.

The new estimate raises further questions about satellite and field measurements of alpine glaciers, and “will set the cat among the pigeons,” says Graham Cogley, a remote-sensing expert at Trent University in Peterborough, Ontario, in an accompanying News and Views article4. Although the ICESat results show twice as much ice loss as the re-interpreted GRACE data, this figure is still three times lower than regional losses estimated on the basis of field studies5.

Data correction

ICESat was launched by NASA in 2003 to track changes in polar ice sheets by measuring their surface elevations with a laser altimeter. “It was designed for smooth topography of the polar regions and cannot be readily used to map rough terrains such as the Himalayas,” says Andreas Kääb, a remote-sensing expert in the University of Oslo in Norway, who led the latest study.

To get around this problem, the team systematically corrected the ICESat data using elevation measurements from the Shuttle Radar Topography Mission, an international research effort to generate a high-resolution digital topographic database of Earth.

Kääb and his colleagues also checked the altitude of the adjacent terrain, which should not change over a short period of time, to make sure that any changes in elevation detected by ICESat in the glacier surface are genuine.

Once these corrections and checks were in place, the researchers used the ICESat data to map the region at a resolution of up to 70 metres. Their study shows that, between 2003 and 2008, Himalayan glaciers thinned at a rate of about 21 centimetres a year on average, significantly less than the estimated global average for glaciers and ice caps.

Glacier fate

Kääb warns, however, that the average ice change can be misleading because it conceals large glacier losses in some parts of the Himalayas that are balanced out by smaller changes, or even gains, in others. In northwestern India, for example, glaciers thinned by about 66 centimetres a year, whereas those in the Karakoram on the whole changed little.

Such regional variations “matter a lot for the millions of people living in river basins that are fed by those glaciers”, says Kääb.

“The study is the first regionally complete measurement [of Himalayan glaciers] that is in general agreement with individual field studies,” says Cogley. He points out, however, that discrepancies with other satellite studies and regional-scale field assessments remain. “We need to keep an open mind” about different satellite methods and the fate of Himalayan glaciers, he adds.

Kääb stresses that the study, like the GRACE observations, does not indicate the climate trend or the fate of the Himalayan glaciers, which would require data collected across several decades. “We are merely pointing to a new way to use ICESat, and the results can be used as a baseline for future studies,” he says.

To Lonnie Thompson, a glaciologist at Ohio State University in Columbus, there is an urgent need to understand why these satellite studies differ from each other and from some field measurements, what their sources of errors are, and how they can be better calibrated. “This is the only way to track changes in the 46,000 or so glaciers in the Himalayas and the Tibetan plateau,” he says.

References

1. Matsuo, K. & Heki, K. Earth Planet. Sci. Lett. 290, 30–16 (2010).
2. Jacob, T., Wahr, J., Pfeffer, W. T. & Swenson, S. Nature 482, 514–518 (2012).
3. Kääb, A., Berthier, E., Nuth, C., Gardelle, J. & Arnaud, Y. Nature 488, 495–498 (2012).
4. Cogley, G. Nature 488, 468–469 (2012).
5. Bolch, T. et al. Science 336, 310–314 (2012).

New paper finds glaciers may be advancing in size in Asia

A paper published today in The Cryosphere studies 136 glaciers in the Karakoram, a large mountain range in Asia, and finds an overall [statistically-insignificant] increase in glacier area since 1989. 

According to the authors, "The area of the investigated glaciers, including the 18 surge-type glaciers identified, showed no significant changes during all studied periods. However, the analysis provides a hint that the overall glacier area slightly decreased until about 1989 (area 1973: 1613.6 ± 43.6 km2; area 1989: 1602.0 ± 33.6 km2) followed by an increase (area 2002: 1609.7 ± 51.5; area 2011: 1615.8 ± 35.5 km2). Although the overall change in area is insignificant, advances in glacier tongues since the end of the 1980s are clearly visible. Detailed estimations of length changes for individual glaciers since the 1970s and for Central Rimo Glacier since the 1930s confirm the irregular retreat and advance."

The Cryosphere, 7, 1385-1398, 2013 www.the-cryosphere.net/7/1385/2013/ doi:10.5194/tc-7-1385-2013

Heterogeneity in glacier response in the upper Shyok valley, northeast Karakoram
R. Bhambri¹, T. Bolch^2,3, P. Kawishwar⁴, D. P. Dobhal¹, D. Srivastava¹, and B. Pratap^1
1Centre for Glaciology, Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun-248001, India
²Geographisches Institut, Universität Zürich, Winterthurer Str. 190, 8057 Zurich, Switzerland
³Institut für Kartographie, Technische Universität Dresden, 01069 Dresden, Germany
⁴Chhattisgarh Council of Science and Technology, MIG-25, Indrawati Colony, Raipur-492001, India
Abstract. Glaciers in the Karakoram show long-term irregular behaviour with comparatively frequent and sudden advances. A glacier inventory of the upper Shyok valley situated in northeast Karakoram has been generated for the year 2002 using Landsat ETM+ and SRTM3 DEM as baseline data for the investigations and subsequent change analysis. The upper Shyok valley contained 2123 glaciers (larger than 0.02 km² in size) with an area of 2977.9 ± 95.3 km² in 2002. Out of these, 18 glaciers with an area of 1004.1 ± 32.1 km²showed surge-type behaviour. Change analysis based on Hexagon KH-9 (years 1973 and 1974) and Landsat TM/ETM+ (years 1989, 2002 and 2011) images had to be restricted to a subset of 136 glaciers (covering an area of 1609.7 ± 51.5 km² in 2002) due to adverse snow conditions. The area of the investigated glaciers, including the 18 surge-type glaciers identified, showed no significant changes during all studied periods. However, the analysis provides a hint that the overall glacier area slightly decreased until about 1989 (area 1973: 1613.6 ± 43.6 km²; area 1989: 1602.0 ± 33.6 km²) followed by an increase (area 2002: 1609.7 ± 51.5; area 2011: 1615.8 ± 35.5 km²). Although the overall change in area is insignificant, advances in glacier tongues since the end of the 1980s are clearly visible. Detailed estimations of length changes for individual glaciers since the 1970s and for Central Rimo Glacier since the 1930s confirm the irregular retreat and advance.

New paper finds potential sea level rise from Greenland is about 66% less than previously estimated

A new paper published in Nature finds the upper limit to sea level rise by 2100 from the Greenland ice sheet is about 66% less than previously predicted. The paper follows another from last week demonstrating the upper limit of sea level rise by 2100 from the Antarctic ice sheet is about 70% less than IPCC predictions. These new papers demonstrate IPCC predictions of sea level rise from both Greenland and Antarctica have been greatly exaggerated. Furthermore, the new estimates of these upper limits may themselves be exaggerated, since they are based upon models with high sensitivity to CO2, which has also been debunked by several recent papers. 

Ice loss from Greenland's glaciers may level off

Simulation suggests long-term effect on sea level not as dire as some predictions

By Erin Wayman

Science News Web edition: May 8, 2013

A+ A- Text Size

ENLARGE

ICE ON THE MOVE

The acceleration of iceberg calving from Greenland’s glaciers could level off by midcentury, researchers predict. Shown is the edge of Kangiata Nunata Sermia where the glacier meets the ocean.

Dirk van As

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The increasing pace of ice breaking off Greenland’s glaciers and dumping into the ocean may not actually be a warning sign of runaway ice loss and catastrophic sea level rise, researchers report in the May 9 Nature.

Greenland’s ice sheet raises sea level when the surface melts or when glaciers flow into the sea and discharge icebergs. Scientists have been concerned that the last decade’s acceleration in iceberg calving would continue unchecked. Simulations have been unable to verify or refute those fears because it’s difficult to account for all of the processes, such as warm seawater’s melting of a glacier’s base, that influence how the streams of ice move and shed icebergs.

Now, Faezeh Nick of the Université Libre de Bruxelles in Belgium and colleagues have incorporated all of these variables into a simulation that predicts the activity of four of Greenland’s main glaciers. In a scenario where global temperatures warm 2.8 degrees Celsius by 2100, the glaciers’ rate of ice loss eventually levels off, the simulation suggests. In total, the four glaciers could raise sea level by about 1 centimeter by 2100.

Applying the findings to the rest of the island’s glaciers, the researchers predict Greenland could add as much as 18.3 centimeters to sea level by the end of the century. That amount is about 35 centimeters less than a previous estimate that extrapolated Greenland’s current ice loss acceleration into the future. 

CITATIONS

F.M. Nick et al. Future sea-level rise from Greenland’s main outlet glaciers in a warming climate. Nature. Vol. 497, May 9, 2013, p. 235. doi:10.1038/nature12068.[Go to]

SUGGESTED READING

E. Wayman. Shrinking polar ice caused one-fifth of sea level rise. Science News. Vol. 182, December 29, 2012, p. 10. [Go to]

D. Powell. Study keeps pace with Greenland glaciers. Science News. Vol. 181, June 2, 2012, p. 10. [Go to]

A. Witze. Ice in motion. Science News. Vol. 179, March 26, 2011, p. 22. [Go to]

New paper finds 4 Alaskan glaciers are about the same size as during the Medieval Warm Period

A paper published today in Quaternary Science Reviews reconstructs the size of four glaciers in Alaska over the past 1500-2000 years. For each of the four glaciers, the authors find the termination point at the end of the record in the late 20th century was approximately the same as during the Medieval Warm Period ~1,000 years ago. According to the paper, the data "supports solar irradiance as the primary pacemaker for centennial-scale fluctuations of mid-latitude valley glaciers prior to the 20th century." The authors find all four glaciers advanced during the Little Ice Age, which was the coldest period of the past 10,000 years, and have regressed during the recovery from the LIA to termination points similar to those during the Medieval Warm Period.

Glacier regression from the Holocene maximum shown for 4 Alaskan glaciers. Total Solar Irradiance shown in orange graph, volcanic activity by black graph.

Late Holocene glacial history of the Copper River Delta, coastal south-central Alaska, and controls on valley glacier fluctuations

• David J. Barclay^a, , , 
• Elowyn M. Yager^b, 
• Jason Graves^a, 
• Michael Kloczko^a, 
• Parker E. Calkin^c

• ^a Geology Department, SUNY Cortland, Cortland, NY 13045, USA
• ^b Center for Ecohydraulics Research, Department of Civil Engineering, University of Idaho, Boise, ID 83702, USA
• ^c INSTAAR, University of Colorado at Boulder, Boulder, CO 80309, USA

Highlights

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Late Holocene histories were reconstructed for four valley glaciers in Alaska.

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Tree-ring based dating methods provide high temporal and spatial resolution.

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Glacier termini have made four major advances in the past 2000 years.

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Solar output paced mid-latitude valley glacier fluctuations in late Holocene.

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Abstract

Fluctuations of four valley glaciers in coastal south-central Alaska are reconstructed for the past two millennia. Tree-ring crossdates on 216 glacially killed stumps and logs provide the primary age control, and are integrated with glacial stratigraphy, ages of living trees on extant landforms, and historic forefield photographs to constrain former ice margin positions. Sheridan Glacier shows four distinct phases of advance: in the 530s to c.640s in the First Millennium A.D., and the 1240s to 1280s, 1510s to 1700s, and c.1810s to 1860s during the Little Ice Age (LIA). The latter two LIA advances are also recorded on the forefields of nearby Scott, Sherman and Saddlebag glaciers. Comparison of the Sheridan record with other two-millennia long tree-ring constrained valley glacier histories from south-central Alaska and Switzerland shows the same four intervals of advance. These expansions were coeval with decreases in insolation, supporting solar irradiance as the primary pacemaker for centennial-scale fluctuations of mid-latitude valley glaciers prior to the 20th century. Volcanic aerosols, coupled atmospheric-oceanic systems, and local glacier-specific effects may be important to glacier fluctuations as supplemental forcing factors, for causing decadal-scale differences between regions, and as a climatic filter affecting the magnitude of advances.

New paper finds worldwide glacier retreat has decelerated since 1950

A paper published today in The Cryosphere studies glacier length data available worldwide since 1800 and finds that glaciers retreated faster during the first half of the 20th century than the second half from 1950-2000. This is the opposite pattern that would be expected if man-made greenhouse gases were the cause, and suggests a natural origin. Most warmists and the IPCC claim man-made greenhouse gases did not begin to affect climate until after 1950, and thus can't be blamed for the fastest rate of glacier retreat from ~1850-1950 and subsequent deceleration. 

The authors find glaciers showed little change in length during the latter part of the Little Ice Age 1800-1850, but following the end of the Little Ice Age in ~1850 most began a relatively rapid retreat that began to decelerate after ~1950. The data shows that calving glaciers [red lines in fig 10a below] reversed to a net advancing trend after ~2001, and that the number of calving glaciers [fig 10b below] has sharply decreased from ~99% to 50% since the year 2000. 

The Cryosphere, 8, 659-672, 2014 www.the-cryosphere.net/8/659/2014/ doi:10.5194/tc-8-659-2014 A data set of worldwide glacier length fluctuations

P. W. Leclercq^1,*, J. Oerlemans¹, H. J. Basagic², I. Bushueva³, A. J. Cook⁴, and R. Le Bris^5
1Institute for Marine and Atmospheric research Utrecht, Utrecht University, Princetonplein 5, Utrecht, the Netherlands
²Department of Geology, Portland State University, Portland, OR 97207, USA
³Institute of Geography Russian Academy of Sciences, Moscow, Russia
⁴Department of Geography, Swansea University, Swansea, SA2 8PP, UK
⁵Department of Geography, University of Zürich, Zurich, Switzerland
^*now at: Department of Geosciences, University of Oslo, P.O. Box 1047, Blindern, 0316 Oslo, Norway
Abstract. Glacier fluctuations contribute to variations in sea level and historical glacier length fluctuations are natural indicators of past climate change. To study these subjects, long-term information of glacier change is needed. In this paper we present a data set of global long-term glacier length fluctuations. The data set is a compilation of available information on changes in glacier length worldwide, including both measured and reconstructed glacier length fluctuations. All 471 length series start before 1950 and cover at least four decades. The longest record starts in 1535, but the majority of time series start after 1850. The number of available records decreases again after 1962. The data set has global coverage including records from all continents. However, the Canadian Arctic is not represented in the data set. The available glacier length series show relatively small fluctuations until the mid-19th century, followed by a global retreat. The retreat was strongest in the first half of the 20th century, although large variability in the length change of the different glaciers is observed. During the 20th century, calving glaciers retreated more than land-terminating glaciers, but their relative length change was approximately equal. Besides calving, the glacier slope is the most important glacier property determining length change: steep glaciers have retreated less than glaciers with a gentle slope.

Why changing sea ice and glaciers do not indicate man-made global warming

Glacial chill ebbs and flows

• BY:IAN PLIMER 
• From:The Australian 
• December 17, 2011 12:00AM

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Ice conditions at the end of the Arctic melt season in 2007, captured 
by NASA's Advanced Microwave Scanning Radiometer and overlaid
on the NASA Blue Marble. Source: AFP

ICE sheets grow and shrink. At times, they disappear. At other times, ice starts to cover polar areas and high mountains. That's what ice has done over the history of our planet. The Greenland and Antarctic basins are more than 1km deep, and deeper in the centres than around the edges, so that ice is squeezed uphill like toothpaste out of a tube by the weight of overlying ice. The alarmist media stresses that changing sea ice and continental glaciers indicate rapid global warming. Is this really so?

Since the last interglacial started some 10,500 years ago, summer sea ice in the Arctic has been far from constant. Sea ice comes and goes without leaving a clear record. For this reason, our knowledge about its variations and extent was limited before we had satellite surveillance or observations from aeroplanes and ships. A huge amount of the earth's surface water moves alternately between the ice sheets and the oceans.

Svend Funder, commenting on his recent Science paper, stated: "Our studies show that there have been large fluctuations in the amount of summer sea ice during the last 10,000 years. During the so-called Holocene Climate Optimum, from approximately 8000 to 5000 years ago, when the temperatures were somewhat warmer than today, there was significantly less sea ice in the Arctic Ocean, probably less than 50 per cent of the summer 2007 coverage, which is absolutely the lowest on record.

"Our studies also show that when the ice disappears in one area, it may accumulate in another. We have discovered this by comparing our results with observations from northern Canada. While the amount of sea ice decreased in northern Greenland, it increased in Canada. This is probably due to changes in the prevailing wind systems. This factor has not been sufficiently taken into account when forecasting the imminent disappearance of sea ice in the Arctic Ocean."

In order to reach their unsurprising conclusions, Funder and the rest of the team organised several expeditions to Peary Land in northern Greenland. Funder said: "Our key to the mystery of the extent of sea ice during earlier epochs lies in the driftwood we found along the coast. One might think that it had floated across (the) sea, but such a journey takes several years, and driftwood would not be able to stay afloat for that long. The driftwood is from the outset embedded in sea ice and reaches the north Greenland coast along with it. The amount of driftwood therefore indicates how much multi-year sea ice there was in the ocean back then. And this is precisely the type of ice that is in danger of disappearing today."

What is interesting about this study is that the new understanding came from getting away from computer modelling and doing fieldwork in pretty inhospitable areas. Back in the laboratory and again away from computer models, the wood type was determined and dated using carbon-14. This wood came from near the great rivers of present-day North America and Siberia. This shows that wind and current directions have changed. The field study of coastal beach ridges shows that at times there were waves breaking unhindered by ice over at least 500km of coastline. At other times, due to sea ice cover, there were no beaches. This is the present situation.

Even if there is a great reduction in sea ice, all is not lost. Funder stated: "Our studies show that there are great natural variations in the amount of Arctic sea ice. The bad news is that there is a clear connection between temperature and the amount of sea ice. And there is no doubt that continued global warming will lead to a reduction in the amount of summer sea ice in the Arctic Ocean. The good news is that even with a reduction to less than 50 per cent of the current amount of sea ice, the ice will not reach a point of no return: a level where the ice no longer can regenerate itself even if the climate was to return to cooler temperatures.

"Finally, our studies show that the changes to a large degree are caused by the effect that temperature has on the prevailing wind systems. This has not been sufficiently taken into account when forecasting the imminent disappearance of the ice, as often portrayed in the media."

Those playing with computer climate models need to get outside, collect new data and take into account far more factors than they feed into computer models.

Studies of the behaviour of tropical glaciers over the last 11,000 years show irregular shrinkage, with slower rates in the Little Ice Age and faster rates in the 20th century. Glaciers such as the Bolivian Telata glacier reflect long-term warming during the current 10,500-year-long interglacial and that glacial retreat was in progress thousands of years before industrialisation.

Scientists urged on by the media state that ice calving off glaciers indicates global warming. Ice always falls off the front of a glacier. If ice did not melt, then the planet would now be covered in ice. Ice drops off the toe of both advancing and retreating glaciers and the melting snout of a glacier is at a point determined by the balance between the forward movement of the ice by gravity and the rate at which it melts. Ice falling off the front of a glacier means absolutely nothing when the air temperature is less than zero. Ice sheets grow and contract. At times, ice sheets disappear. The story of glacial retreat is far more complex than a television image.

Many glaciers that are now in retreat did not exist until the Little Ice Age (which climaxed in the middle to late 17th century). During the medieval warming (which peaked around AD1000), alpine glaciers in the northern hemisphere were smaller or did not exist. Over much of the Canadian Cordillera, there may have been no glaciers at all during the Holocene Maximum (8000 to 6500 years ago), when temperatures were considerably higher than now.

Records from New Zealand and Norway show glacier retreat started in the 18th and 19th centuries. Most of the modern ice retreat is due to post-Little Ice Age warming, changes in humidity and a decrease in ice flow rates.

The idea that a glacier slides downhill on a base lubricated by melt water was a good idea when first presented by Horace-Benedict de Saussure in 1779. We now know a lot more, yet this treasured idea remains. Ice moves by creep, a process of constant recrystallisation of ice crystals. Ice at the snout of a glacier has crystals 1000 times larger than those in snow as a result of growth during recrystallisation.

Ice sheets in Antarctica and Greenland first flow uphill before flowing down glaciers. The upward flow of ice cannot be due to human-induced global warming producing melting. There are some places in the world today where glaciers are expanding.

Ice sheets and glaciers grow and retreat for a great diversity of reasons. For scientists to argue that ice retreat is due to human activity is simplifying a very complex process. Furthermore, it is too cold in Antarctica and Greenland for ice to melt.

Since the discovery of the Hubbard Glacier (in Alaska) in 1895, it has been advancing 25m a year during periods of cooling and warming. The ice front is 10km long and 27m high. What does the ice do at the snout of the glacier? It falls off, because it is getting pushed from behind. This has nothing to do with temperature; it shows ice behaves as a plastic and brittle material and that ice sheets are always changing.

As with all areas of science, there are regular surprises. It was always thought that ice formed from frozen snow. The science was settled and there was a consensus. Recent work in East Antarctica shows that the deepest part of the ice sheet contains ice that did not originate as snow. It was melt water that seeped to the base of the ice sheet and then froze. The amount of ice formed by this method is probably greater in volume than all the glaciers on earth outside Antarctica and Greenland. The computer models predicted this melt-water escaped to the oceans and contributed to sea level rise. Wrong. The volume of water in this ice is larger than Antarctica's sub-glacial lakes. The addition of hundreds of metres of ice at the base of an ice sheet bends the overlying ice and causes uplift of the surface of the glacier. This changes the slope and flow of the ice. The thickest sub-glacial ice was 1100m and this pushed the top of glaciers up 410m to reflect the shape of the added basal ice.

Antarctica has another little surprise. Underneath the ice sheets are volcanoes. The last big eruption was in Roman times and Mount Erebus is continually restless. Addition of heat from below could cause massive melting and detachment of a large block of ice.

As snow falls, it traps air. This air is preserved as the snow becomes an ice sheet. This air remains trapped and uncontaminated in ice, otherwise it cannot be used to measure past atmospheres. Antarctic ice core (Siple) shows that there were 330 parts per million of carbon dioxide in the air in 1900; Mauna Loa Hawaiian measurements in 1960 show that the air then had 260ppm carbon dioxide.

Either the ice core data is wrong, the Hawaiian carbon dioxide measurements are wrong, or the atmospheric carbon dioxide content was decreasing during a period of industrialisation.

As in all other areas of science, uncertainty rules.

This is an extract from Ian Plimer's book How to Get Expelled from School: A Guide to Climate Change for Pupils, Parents & Punters.