A half-century worth of data on glacial advance and retreat released by the Interior Department clearly illustrates how climate change is affecting these rivers of ice in Alaska and Washington state.
Formally released Thursday by Interior Secretary Ken Salazar, the USGS study shows that glaciers are dramatically changing in mass, length and thickness as a result of climate change. The specific glaciers monitored by the USGS were Alaska’s Gulkana and Wolverine glaciers and Washington’s South Cascade Glacier. The study is the longest compiled on glaciers in North America, according to Interior officials.
“This report we are releasing today is great example of the science and data our department has gathered over the past 50 years,” said Secretary Salazar. “This information is helpful in tackling the effects of climate change and it is exactly the kind of science we need to invest in to measure and mitigate the dangerous impacts of climate change.”
Glacier shrinkage has global impacts, including sea level rise that threatens low-lying and coastal communities. Smaller glaciers will also result in a decrease of water runoff, and impacts are especially important during the dry late summer when other water sources are limited.
“There is no doubt that most mountain glaciers are shrinking worldwide in response to a warming climate. Measuring changes in glacier mass provides direct insight to the link between glaciers and climate, ultimately helping predict glacier response to anticipated climate conditions,” said USGS scientist Edward Josberger.
The three glaciers monitored for the study are known as benchmark glaciers. They are widely spaced, represent different climate regimes, and can be used to understand the thousands of other glaciers in nearby regions.
USGS scientists study glacier behavior during different seasons, including summer melt and winter snow accumulation, as well as their response to both short and long term climate variations. This allows for more detailed insight regarding how and when the climate is changing.
“In addition to these three glaciers, more than 99 percent of America’s thousands of large glaciers have long documented records of an overall shrinkage as climate warms,” said USGS scientist Bruce Molnia. “Many people are surprised to learn that a few glaciers are thickening and advancing. These glaciers are responding to unusual and unique local conditions, including having large, high elevation areas where snow accumulates. Except for these anomalous few , most of America’s glaciers are shrinking and these exceptions emphasize how natural variability is an inherent part of a complex Earth system.”
For a look at how the South Cascade Glacier has receded down through the years, check out the video at this site: http://wa.water.usgs.gov/projects/glacier/video.html
Comments
Thanks for those links, Kurt. Decreased runoff and warmer rivers will also further stress salmon and
steelhead runs.
It's fascinating to me that one of the few advancing glaciers is in the recent crater of Mount St. Helens.
Here's a link to the best photo I could find:
http://geology.rockbandit.net/2008/04/23/mount-st-helens-glacier-growing/
also a locally produced video, that I believe shows the glacier surrounding the lava dome:
http://www.opb.org/programs/ofg/videos/view/287-Return-to-Mt-St-Helens
I believe glaciers on Mount Shasta in northern California are growing as well. I seem to recall that the warming Pacific of recent winters is responsible, as it produced some prodigious snowstorms on Shasta and other coastal ranges.
Wow! The video is pretty grim. Kurt, thank you for the links. They reinforce what we already know, that glaciers are retreating all over the world. I attach a link of a NASA article which goes into detail about the retreat of the Greenland ice sheets. This article includes photos illustrating the retreat over time: http://www.nasa.gov/vision/earth/lookingatearth/jakobshavn.html
To my mind the evidence is overwhelming, but from comments made on similar articles on this site I know there are those who choose to discount any mention of global warming. Their "skepticism" reeks of energy interest profiteering, and certainly makes the case for "fundamentalism". I suppose those same people would also deny the existence of the laws of physics.
As a scientist, I must say that the pictures and video are quite disturbing and certainly demonstrate that our climate is changing - the laws of physics are most assuredly in play. As a scientist, I must also say that evidence is quite strong that change in climate is not caused by what we do here but rather by solar activity - and that is not a ploy or plot against Al Gore, just trying to ALL of the facts:
http://www.junkscience.com/Greenhouse/
Jimi, I do not question your title as a scientist. However, I am surprised that you use the junkscience site as a credible source of scientific data. I suggest that USGS, NASA, and meteorological research divisions associated with major universities might be more appropriate sources of climate related information and opinion. I believe human forcing plays a significant role in modern climate change.
Ray - you are right, I had just read that and it was a quick fresh reference. I agree, as I did before, that there is massive change - but, I still have not seen ANY evidence that it is caused by man. The near surface Earth temperature is actually going down, has over the last ten years? Is that more likely to be due to less activity by man or less solar activity?
Beamis - I tend to agree with you that most of what is happening is due to solar activity, that is what I have read from most scientsts that ARE NOT FUNDED BY THE GOVERNMENT. Several years ago, television channels that were delivered by satelite were constantly bothered by solar flares - not so much any more? That, of course, is anecdotal as is most of what we read about 'global warming.' I do see a pattern in results depending on where the funding for the research comes from - not saying that either side has convinced me, but it is disturbing to know that the answer depends on the funding organization. I know I am repeating but I have seen evidence that solar activity is cyclic and that we are approaching a cool spell and I have seen NO evidence that man has any affect on the near surface temperature of the Earth, hence no effect on the temperature of the 'globe.'.
With all due respect to Jimi I would rather put my faith in the facts as presented by scientific entities like NASA and USGS. The junkscience site just doesn't inspire my confidence. There's so many disclaimers in it, it's no wonder that whoever wrote it wasn't even confident enough to put his name on it. I think there's plenty of documented proof out there of how human activity degrades Earth's biosphere. No amount of smoke and mirrors will make it go away. As for predictions, there's so much we DON'T know that our best guess may as well come from a fortune cookie.