Background
As background material for their enlightening study, the authors write that "the Karakoram mountains of Pakistan, India, Afghanistan, and China contain some of the largest non-polar glaciers in the world," noting that they "exist at high altitude (~2500-8600 meters above sea level), and provide a crucial source of water for nearby communities." But are they growing or shrinking, in this supposedly rapidly warming world of ours? That is the question that is on the minds of the inhabitants of those "nearby communities" that depend upon them for their water.

What was done
Copland et al. attempt to answer this burning question "by using a combination of previously published literature and repeat satellite imagery to catalogue surge-type glaciers and monitor their distribution, surge history, and physical characteristics across the entire mountain range."

What was learned
The eight researchers report that "there has been a marked increase in the recent occurrence of glacier surging in the Karakoram," which they say is associated with "a significant increase in winter, summer, and annual precipitation in the Karakoram over the period 1961-1999." More specifically, they say there has been "a doubling in the number of new surges in the 14 years after 1990 (26 surges) than in the 14 years before 1990 (13 surges)," and they state that the recent increase in glacier surging "appears to be a response to positive mass balances over the Karakoram over the past few decades, and is in line with the many other glaciological indicators of recent changes in this area," among which they include "the recent stability and expansion of many non-surge glaciers in this region," citing Hewitt (2005), Pecci and Smiraglia (2000) and Mayer et al. (2006), as well as "increases in surface velocity (Quincey et al., 2009)," which they attribute to "increases in snowfall."

What it means
In concluding, Copland et al. reiterate that contrary to what is often claimed about many of earth's mountain glaciers by the world's climate alarmists, "it is evident that glacier surging is more extensive than previously reported in the Karakoram and that the number of glacier surges has increased recently," driven, as noted above, by positive mass balances.

References
Hewitt, K. 2005. The Karakoram anomaly? Glacier expansion and the 'elevation effect," Karakoram Himalaya. Mountain Research and Development 25: 332-340.

Mayer, C., Lambrecht, A., Belo, M., Smiraglia, C. and Diolaiuti, G. 2006. Glaciological characteristics of the ablation zone of Baltoro glacier, Karakoram, Pakistan. Annals of Glaciology 43: 123-131.

Pecci, M. and Smiraglia, C. 2000. Advance and retreat phases of the Karakorum glaciers during the 20th century: case studies in Braldo Valley (Pakistan). Geografia Fisica e Dinamica Quaternaria 23: 73-85.

Quincey, D.J., Copland, L., Mayer, C., Bishop, M., Luckman, A. and Belo, M. 2009. Ice velocity and climate variations for the Baltoro Glacier, Pakistan. Journal of Glaciology 55: 1061-1071.