World’s glaciers melting at fastest rate since record-keeping began – ‘Globally, we lose about three times the ice volume stored in the entirety of the European Alps every year’Posted by Jim at Tuesday, August 04, 2015
3 August 2015 (University of Zurich) – The World Glacier Monitoring Service, domiciled at the University of Zurich, has compiled worldwide data on glacier changes for more than 120 years. Together with its National Correspondents in more than 30 countries, the international service just published a new comprehensive analysis of global glacier changes in the Journal of Glaciology. In this study, observations of the first decade of the 21st century (2001-2010) were compared to all available earlier data from in-situ, air-borne, and satellite-borne observations as well as to reconstructions from pictorial and written sources.
“The observed glaciers currently lose between half a metre and one metre of its ice thickness every year - this is two to three times more than the corresponding average of the 20th century”, explains Michael Zemp, Director of the World Glacier Monitoring Service and lead author of the study. “Exact measurements of this ice loss are reported from a few hundred glaciers only. However, these results are qualitatively confirmed from field and satellite-based observations for tens of thousands of glaciers around the world.”
According to the international author team, the current rate of glacier melt is without precedence at global scale, at least for the time period observed and probably also for recorded history, as indicated also in reconstructions from written and illustrated documents. In addition, the study shows that the long-term retreat of glacier tongues is a global phenomenon. Intermittent re?advance periods at regional and decadal scales are normally restricted to a subsample of glaciers and have not come close to achieving the Little Ice Age maximum positions reached between the 16th and 19th century. As such, glacier tongues in Norway have retreated by some kilometres from its maximum extents in the 19th century. The intermittent re-advances of the 1990s were restricted to glaciers in the coastal area and to a few hundred metres.
In addition, the study indicates that the intense ice loss of the past two decades has resulted in a strong imbalance of glaciers in many regions of the world. “These glaciers will suffer further ice loss, even if climate remains stable”, explains Michael Zemp.
ABSTRACT: Observations show that glaciers around the world are in retreat and losing mass. Internationally coordinated for over a century, glacier monitoring activities provide an unprecedented dataset of glacier observations from ground, air and space. Glacier studies generally select specific parts of these datasets to obtain optimal assessments of the mass-balance data relating to the impact that glaciers exercise on global sea-level fluctuations or on regional runoff. In this study we provide an overview and analysis of the main observational datasets compiled by the World Glacier Monitoring Service (WGMS). The dataset on glacier front variations (~42 000 since 1600) delivers clear evidence that centennial glacier retreat is a global phenomenon. Intermittent readvance periods at regional and decadal scale are normally restricted to a subsample of glaciers and have not come close to achieving the maximum positions of the Little Ice Age (or Holocene). Glaciological and geodetic observations (~5200 since 1850) show that the rates of early 21st-century mass loss are without precedent on a global scale, at least for the time period observed and probably also for recorded history, as indicated also in reconstructions from written and illustrated documents. This strong imbalance implies that glaciers in many regions will very likely suffer further ice loss, even if climate remains stable.
By Nick Visser
3 August 2015
(Huffington Post) – The world's glaciers have melted to the lowest levels since record-keeping began more than 120 years ago, according to a study conducted by the World Glacier Monitoring Service that was released on Monday.
The research, published in the Journal of Glaciology, provides new evidence that climate change has spurred the rapid decline of thousands of the world's ice shelves over the past century. The first decade of the 21st century saw the fastest loss of ice since scientists began tracking it in 1894 -- and perhaps in recorded history, WGMS reported.
"Globally, we lose about three times the ice volume stored in the entirety of the European Alps every year," Michael Zemp, director of the WGMS and lead author of the study, told The Huffington Post.
On average, the world's glaciers will lose 30 inches of ice thickness this year, Zemp said. That's twice the rate lost in the 1990s, and three times the rate lost in the 1980s.
The news comes just a few months before many of the world's leaders gather in Paris for the United Nations Conference on Climate Change. The planet's leading scientists have emphasized the importance of reaching a deal, saying there is "no plan B" if the talks fail.
The latest news on ice melt continues a trend of worrying statistics. The planet saw the warmest year on record in 2014, and researchers observed the lowest maximum ice extent ever seen earlier this year. All of that lost ice will very likely contribute to catastrophic sea level rise, which some scientists predict could approach 10 feet in the next 50 years.
Preliminary data for the past five years suggest that the melting has continued at an alarming rate, and the "bad news is getting worse," according to Zemp. Up to 90 percent of the glaciers in the European Alps could disappear by the end of the century. […]
"I always say to people, 'Go take your children and sit in front of the glacier and take a picture, then go back every year,'" he said. "It reminds you of what you could lose." [more]