quote:

ORIGINAL: Vendaval

"Scientists: Antarctic ice sheet thinning"
 
POSTED: 4:49 p.m. EDT, March 29, 2007

"HOUSTON, Texas (Reuters) -- A Texas-sized piece of the Antarctic ice sheet is thinning, possibly due to global warming, and could cause the world's oceans to rise significantly, polar ice experts said on Wednesday.

They said "surprisingly rapid changes" were occurring in Antarctica's Amundsen Sea Embayment, which faces the southern Pacific Ocean, but that more study was needed to know how fast it was melting and how much it could cause the sea level to rise.

The warning came in a joint statement issued at the end of a conference of U.S. and European polar ice experts at the University of Texas in Austin."

http://www.cnn.com/2007/TECH/science/03/29/antarctic.ice.reut/index.html

Global sea levels are predicted to rise as a result of global warming, but many contributions to this sea level rise are poorly understood. The contribution of the Antarctic ice sheet is particularly uncertain. In his Perspective, Vaughan highlights the report by Davis et al., who have used satellite data to compile an 11-year record of surface elevation change in Antarctica. The resulting maps show that the ice sheet is thickening in some areas and thinning in others.

In a recent issue of Science, Andrew Monaghan of Ohio State University’s Byrd Polar Research Center collaborated with fifteen colleagues from around the world on a piece describing their assemblage of a fifty-year time series of snowfall accumulation over Antarctica. To produce the time series the scientists combined climate model simulations, snowfall observations derived from a multitude of new ice core records, and snow pit and snow stake data. Antarctic ice sheets are of interest to climate change scientists because recent studies suggest a strong winter warming signal in the lower atmosphere over Antarctica since the early 1970s. An interesting twist to this is that future scenarios from global climate change models suggest that Antarctic snowfall should actually increase in a warming climate, as the warmer atmosphere comes with a greater capacity for moisture. Intuitively, increased snow accumulation supports ice sheet thickening.

However, Monaghan et al. note that there is evidence of conflicting trends in ice sheet thickness across Antarctica: the West Antarctic Ice Sheet has been thinning over the past decade, while the East Antarctic Ice Sheet became thicker over the period 1992 through 2003 (Davis et al. 2005). Previous work attributed the thickening of the East Ice Sheet to an increase in snowfall accumulation across that portion of the continent, following the logic of a warmer atmosphere and therefore greater moisture capacity. The thinning of the West Ice Sheet, however, is not well explained. As it turns out, Monaghan and his colleagues do not think that the thickening of the East Ice Sheet is well explained either!

The group of researchers reports that across both the East and West Ice Sheets “there are no statistically significant trends in snowfall accumulation over the past 5 decades, including recent years for which global mean temperatures have been warmest.” Clearly stated by Monaghan et al. in the article is that they do not dispute a clear thickening signal in the East Ice Sheet.

...


To further thicken the plot, not to mention the mass of Antarctica, a recent article by Van de Berg et al. in the Journal of Geophysical Research describes a reassessment of the surface mass balance of Antarctica. The group compared results of the model-simulated surface mass balance for the continent to all available mass balance observations in a recalibration process that allowed them to construct a “best estimate” of contemporary Antarctic mass balance. What was found by the work is striking: the newly estimated surface mass balance “exceeds previous estimates by as much as 15%.”

...

The group of Dutch researchers contends that the new estimate of the mass balance of Antarctica is as reliable as the reliability given to current atmospheric models. The only improvement that could be offered would have to come from new surface mass balance observations from poorly covered high accumulation regions in coastal Antarctica. Until then, there is little evidence to disprove their conclusion that the mass of Antarctica’s grounded ice sheet steadily grew from 1980 to 2004.

quote:

ORIGINAL: Sinergy


Thank you for pointing out that the general thickness has increased from 1984 to 2004.

Dazzle us with your scientific knowledge, FirmKY.

How much has antarctica shrunk in the last 200 years? 

From a statistical standpoint, is the general trend over 200 years one of growth or one of shrinking?


Sinergy

quote:

ORIGINAL: Sinergy


Thank you for pointing out that the general thickness has increased from 1984 to 2004.

Dazzle us with your scientific knowledge, FirmKY.

How much has antarctica shrunk in the last 200 years? 

From a statistical standpoint, is the general trend over 200 years one of growth or one of shrinking?

From 1992 to 2003, Curt Davis, MU professor of electrical and computer engineering, and his team of researchers observed 7.1 million kilometers of the ice sheet, using satellites to measure changes in elevation. They discovered that the ice sheet's interior was gaining mass by about 45 billion tons per year, which was enough to slow sea level rise by .12 millimeters per year.

...

"Many recent studies have focused on coastal ice sheet losses and their contributions to sea level rise," Davis said. "This study suggests that the interior areas of the ice sheet also can play an important role. In particular, the East Antarctic ice sheet is the largest in the world and contains enough mass to raise sea level by more than 50 meters. Thus, only small changes in its interior can have a significant affect on sea level."

...

"Ice sheet response to climate change is a complex process that is difficult to measure and even more difficult to predict," Davis said. "The overall contribution of the Antarctic ice sheet to global sea-level change will depend on how mass changes in the ice sheet's interior balance mass changes from the coastal areas."

quote:

ORIGINAL: juliaoceania

Now I for one do not think that playing games with our atmosphere is good idea.
I think that we should err on the side of caution and those who want to continue pumping greenhouse gases into the atmosphere without trying to find alternatives should have to prove global warming will not harm planet earth.. we should not have to prove it will. The cost is just too damn high to humanity to continue on this course if those who believe we have almost reached or surpassed the point of no return are right.

quote:

The "majority" of scientists DO NOT attribute global warming exclusively or predominantly to human activity. 

quote:

ORIGINAL: lockedaway

What about the warming that is taking place on other planets in our galaxy?
Do those other planets in our galaxy have an atmosphere that affects  the suns radiation on that planet?

Is THAT going to blamed on cars also?  The "majority" of scientists DO NOT attribute global warming exclusively or predominantly to human activity.
Could you please give us a cite for this position?

You wanna drive a hybrid?  Drive one, knock yourself out. You want to put solar panels on the roof of your house?  Great...the is a grant available from the Federal Government that will absorb 70% of the costs you incur.  You want to point fingers at other people who drive pick ups or cadillacs or SUV's and cop a santimonious attitude?  That would make you a jerk. 
So the person on a life boat who would take exception to the rich and powerful taking more of the water and food  on that life boat  also be jerks?


While there is no doubt that the earth is in a warming trend, there is considerable doubt at to its source.
I have only noticed that doubt in the minds of those who have a vested interest in preserving their economic position and the academics on their payroll.

(You may find it terribly Orwellian when your hybrid has to communicate with the pump to determine how many miles you have driven since your last fill up and you, essentially, get charged by the mile for your gas.  That Black Box technology is on its way.  Hybrids use less gas thus fewer gasoline taxes collected, less money available for highway maintenance from gasoline sales, etc.
Not to mention less gasoline sold so it would be in the interest of the oil companies to do this no?  Since economy vehicles are typically smaller and cause less wear on the highway might this also be a good way to insure that those who cause the most wear on the roadway pay porportionaly appropriate rates for their use there of?


Figure it out.  With every advancement in technology comes a further encroachment of the govt. into your life.)
Is there any minimum level of government encroachment into your life that you would feel comfortable with?  Should we not have public highways? Public schools?  Police protection? Fire Department.  Public sewer system?  Are you saying that all government social programs are unnecessary or just the ones you don't want to pay for?
thompson

quote:

ORIGINAL: juliaoceania

It never ceases to amaze me that certain people would play with Earth's atmosphere as though it were some huge science experiment that if it went bad we could just start over from scratch... we can't. There is only one Earth type planet that we know of, this planet is where we all live, and if we screw it up through our actions we cannot go and find another. So for those who think it is wise to play with the atmosphere as though we have somewhere else to go once we fuck this one up, I say you are either stupid, ignorant, crazy or a combination of all three... or you are just fucking greedy and you do not give a damn what planet you leave behind.

quote:

ORIGINAL: juliaoceania

Now seeing that many many people just do not see the larger picture, are in denial, and basically do not even want to try to comprehend the nature of what is going on with global warming, I see a very bleak future ahead. Even the most cynical of climatologists admit that CO2 is a greenhouse gas, insurance and other industries are planning for the outcome of our globe warming, this is pretty mainstream science we are talking about. Very few scientists remain in the camp of large auto manufacturers and the petro industry.

quote:

ORIGINAL: juliaoceania

Now I for one do not think that playing games with our atmosphere is good idea. I think that we should err on the side of caution and those who want to continue pumping greenhouse gases into the atmosphere without trying to find alternatives should have to prove global warming will not harm planet earth.. we should not have to prove it will. The cost is just too damn high to humanity to continue on this course if those who believe we have almost reached or surpassed the point of no return are right.

we should not have to prove it will.

quote:

ORIGINAL: Vendaval

"Scientists: Antarctic ice sheet thinning"
 
POSTED: 4:49 p.m. EDT, March 29, 2007

"HOUSTON, Texas (Reuters) -- A Texas-sized piece of the Antarctic ice sheet is thinning, possibly due to global warming, and could cause the world's oceans to rise significantly, polar ice experts said on Wednesday.

They said "surprisingly rapid changes" were occurring in Antarctica's Amundsen Sea Embayment, which faces the southern Pacific Ocean, but that more study was needed to know how fast it was melting and how much it could cause the sea level to rise.

The warning came in a joint statement issued at the end of a conference of U.S. and European polar ice experts at the University of Texas in Austin."

quote:

ORIGINAL: juliaoceania

quote:

Exactly.  We have one planet to live on and it is in our own
best interests to follow the recommendations of the scientific
majority.  The long term consequences of our actions and
inactions will effect our children and their children and their
children's children.

 
Unfortunately many people choose not to study the hard science and believe in the oil industry spokespeople.

quote:

ORIGINAL: popeye1250

quote:

ORIGINAL: juliaoceania

quote:

Exactly.  We have one planet to live on and it is in our own
best interests to follow the recommendations of the scientific
majority.  The long term consequences of our actions and
inactions will effect our children and their children and their
children's children.

 
Unfortunately many people choose not to study the hard science and believe in the oil industry spokespeople.

Firmhand, I'll let you handle that one.