Sludge Watch ==> US Scientists warn - Arctic may have ice free summers by 2040

[Maureen Reilly]

Sludgewatch Admin:

This is a shocking and far reaching study.  We need to look at how sewage 
sludge treatment and land application release gases that contribute to 
global warming.
For instance composting sludge can release as much as 34 lbs / ton of 
methane...a potent green house gas.  While sludge industry moguls seem oddly 
fixated on animal manure ("look over there...bad cow, bad bad cow") they are 
avoiding examination of how human excrement and industrial waste management 
contributes to global demise.

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Arctic sea ice 'faces rapid melt'
By Jonathan Amos
Science reporter, BBC News, San Francisco



A new model forecasts largely ice-free summers by 2040


Enlarge Image

The Arctic may be close to a tipping point that sees all-year-round ice 
disappear very rapidly in the next few decades, US scientists have warned.
The latest data presented at the American Geophysical Union Fall Meeting 
suggests the ice is no longer showing a robust recovery from the summer 
melt.
Last month, the sea that was frozen covered an area that was two million sq 
km less than the historical average.
"That's an area the size of Alaska," said leading ice expert Mark Serreze.
"We're no longer recovering well in autumn anymore. The ice pack may now be 
starting to get preconditioned, perhaps to show very rapid losses in the 
near future," the University of Colorado researcher added.
The sea ice reached its minimum extent this year on 14 September, making 
2006 the fourth lowest on record in 29 years of satellite record-keeping and 
just shy of the all time minimum of 2005.
'Feedback loop'
Dr Serreze's concern was underlined by new computer modelling which 
concludes that the Arctic may be free of all summer ice by as early as 2040.
 This is a positive feedback loop with dramatic implications for the entire 
Arctic region

Marika Holland


Life in the changing Arctic
The new study, by a team of scientists from the National Center for 
Atmospheric Research (NCAR), the University of Washington, and McGill 
University, found that the ice system could be being weakened to such a 
degree by global warming that it soon accelerates its own decline.
"As the ice retreats, the ocean transports more heat to the Arctic and the 
open water absorbs more sunlight, further accelerating the rate of warming 
and leading to the loss of more ice," explained Dr Marika Holland.
"This is a positive feedback loop with dramatic implications for the entire 
Arctic region."
Eventually, she said, the system would be "kicked over the edge", probably 
not even by a dramatic event but by one year slighter warmer than normal. 
Very rapid retreat would then follow.
Locally, this would have major consequences for wildlife in the region, not 
least polar bears which traverse ice-floes in search of food.
Loss of summer ice would seriously compromise the lifestyles of the region's 
indigenous peoples, though it could also bring new trading opportunities as 
sea routes opened up.
On a global scale, the Earth would lose a major reflective surface and so 
absorb more solar energy, potentially accelerating climatic change across 
the world.
Sooner or later
In one of the model's simulations, the September ice was seen to shrink from 
about 5.9 million sq km (2.3 million sq miles) to 1.9 million sq km (770,000 
square miles) in just a 10-year period.
By 2040, only a small amount of perennial sea ice remained along the north 
coasts of Greenland and Canada, while most of the Arctic basin was ice-free 
in September.

"We don't think that state has existed for hundreds of thousands of years; 
this is a dramatic change to the Arctic climate system," Dr Holland told the 
BBC.
Dr Serreze, who is not a modeller and deals with observational data, feels 
the tipping point could be very close.
"My gut feeling is that it might be around the year 2030 that we really see 
a rapid decline of that ice. Now could it occur sooner? It might well. Could 
it occur later? It might well.
"It depends on the aspects of natural variability in the system. We have to 
remember under greenhouse warming, natural variability has always been part 
of the picture and it always will be part of the picture."
The average sea ice extent for the entire month of September this year was 
5.9 million sq km (2.3 million sq miles). Including 2006, the September rate 
of sea ice decline is now approximately -8.59% per decade, or 60,421 sq km 
(23,328 sq miles) per year.
At that rate, without the acceleration seen in the new modelling, the Arctic 
Ocean would have no ice in September by the year 2060.
Jonathan.Amos-INTERNET at bbc.co.uk

http://news.bbc.co.uk/2/hi/science/nature/6171053.stm




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ice could melt clean away during summer by 2040, say scientists
12.12.06




Scientists warn that by 2040 the Arctic Ocean could be left virtually empty 
of ice during the summer months
Almost all the ice in the Arctic could disappear during the summer within 35 
years because of global warming, alarming new research reveals.
Scientists have warned that sea ice may start to retreat four times faster 
than in the past in around 20 years time.
By 2040, this could mean the Arctic Ocean being left virtually empty of ice 
during the summer months.
That would have a devastating impact on creatures such as polar bears whose 
future survival could be put in jeopardy by being forced onto land for too 
long.
The US experts that made the worrying predictions said the loss of ice is 
'far more dramatic than anything that has happened so far.'
But they also said that cutting greenhouse gases could slow down the 
problem.
"Our research indicates that society can still minimise the impacts on 
Arctic ice," said lead scientist Marika Holland of America's National Center 
for Atmospheric Research (NCAR).
The study, which also involved scientists from the University of Washington 
and McGill University, used computers to analyse ice effects in the past, 
and make future predictions.
The Arctic does not have a continental land mass like Antarctica but there 
is a permanent mass of sea ice that forms a jagged circle around the North 
Pole, covering about 70 percent of the Arctic.
However each summer it retreats and by September, it reaches its thinnest 
and smallest point.
The study, published in the journal Geophysical Research Letters, used their 
computer programs to predict what would happen if greenhouse gases continue 
to build up at their current rate.
They found that the Arctic ice will go through periods of relative 
stability, but then will rapidly retreat.
One scenario suggests that September ice could shrink from 2.3 million 
square miles to 770,000 square miles within a 10-year-period.
This would mean by 2040, only a small amount of sea ice remains along the 
north coasts of Greenland and Canada.
Most of the Arctic basin would be ice-free during this month and even in 
winter, the ice would thin from 12 to 3 feet in thickness.
Dr Holland, said: "We have already witnessed major losses in sea ice, but 
our research suggests that the decrease over the next few decades could be 
far more dramatic than anything that has happened so far.
"These changes are surprisingly rapid."
Sea ice reflects the sun's heat back into space, and so if more is lost, 
more rays will be absorbed by the water, helping to accelerate the warming 
trend.
In addition changing ocean circulations could drive warmer currents into the 
region.
"This is a positive feedback loop with dramatic implications for the entire 
Arctic region," warned Dr Holland.
But the study team also found that if emissions of carbon dioxide and other 
greenhouse gases were to slow down, then the risk of rapid ice loss would 
also decrease.
Experts have repeatedly warned that if sea ice melts it could have alarming 
impacts on species such as polar bears.
The bears rely on ice to hunt seals and when the ice reduces during their 
summer they head for land and rely on their stored fat to see them through.
If they are forced to move to the land too early, they may struggle to 
survive and reproduce and this could have a devastating impact on their 
future survival.
http://www.thisislondon.co.uk/news/article-23377891-details/Arctic%20ice%20could%20melt%20clean%20away%20during%20summer%20by%202040,%20say%20scientists/article.do