Global warming = rising water level?

In summary: The ice that is over land, Greenland and the Antartic would take a very long time to melt-Ice shelves that float in the ocean would not affect sea levels if they melted
  • #1
daniel_i_l
Gold Member
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If you have ice cubes in a glass of water and they melt the level of the water goes down. Why are glaciers in the ocean different?
 
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  • #2
The ice that might melt and cause a rise in sea levels is sitting on land, in Antarctica and Greenland.
 
  • #3
Farsight said:
The ice that might melt and cause a rise in sea levels is sitting on land, in Antarctica and Greenland.

in fact, there is enough ice on Greenland to raise ocean levels 7 meters if it all melted and on Antarctica to raise the oceans 60 meters (if i recall correctly) if it all melted. (that would change the coastal map worldwide quite considerably.)

the scary thing is that this is a positive-feedback mechanism. since polar ice reflects sunlight better than brown dirt or gray rock, the warmer the Earth gets, the more of this ice covering ground is melted, the more of this ground is exposed, the more sunlight is absorbed instead of reflected, and the more conditions are changed to enable warming at an even faster rate. if this becomes a "runaway train" that gets away from us (out of control), we could start an avalanche mechanism that our descendants just cannot stop and there is enough stored water "in the bank" that the oceans could rise seemingly indefinitely.

the oceans did rise 1/5 meter in the 20th century and is expected to rise 1 meter in the 21st century. since all of the change agents (human population, carbon consumption, and CO2 levels over the post-ice-age baseline of 275 ppm) are increasing exponentially, if this sea level rise continues exponentially, it could go up 5 meters in the 22nd, perhaps 25 meters in the 23rd century. it's a long way off, but we might be sowing seeds for such a calamity now that our descendants will have a b1tch of a time reversing. it's all because of a life-style of consumption and that fossil fuels were priced so cheaply at the expense of our descendants. in economics, this is called "externalities": when some group of people gets to have a party while another group of people, neither consenting to it nor benefitting from it, get to pay for the party. I'm sure our descendants will be thankful.

we (the human race) better watch out. we could be starting a very slow, but unstoppable, avalanche of global warming.
 
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  • #4
Farsight said:
The ice that might melt and cause a rise in sea levels is sitting on land, in Antarctica and Greenland.
Actually a lot of the ice is not over land. The ice that is over land, Greenland and the Antartic would take a very long time to melt.

To answer the OP's question, Ice shelves that float in the ocean would not affect sea levels if they melted.

"Glaciers and ice caps

Each year about 8 mm (0.3 inches) of water from the entire surface of the oceans goes into the Antarctica and Greenland ice sheets as snowfall. If no ice returned to the oceans, sea level would drop 8 mm every year. Although approximately the same amount of water returns to the ocean in icebergs and from ice melting at the edges, scientists do not know which is greater — the ice going in or the ice coming out. The difference between the ice input and output is called the mass balance and is important because it causes changes in global sea level.

Ice Shelves float on the surface of the sea and, if they melt, to first order they do not change sea level. Likewise, the melting of the northern polar ice cap which is composed of floating pack ice would not significantly contribute to rising sea levels. Because they are fresh, however, their melting would cause a very small increase in sea levels, so small that it is generally neglected. It can however be argued that if ice shelves melt it is a precursor to the melting of ice sheets on Greenland and Antarctica.

Scientists lack knowledge of changes in terrestrial storage of water. Between 1910 and 1990, such changes may have contributed from –1.1 to +0.4 mm/yr.

If all glaciers and ice caps melt, the projected rise in sea level will be around 0.5 m. If the melting includes the Greenland and Antarctic ice sheets (both of which contain ice above sea level), then the rise is a more drastic 68.8 m. [3]

The snowline altitude is the altitude of the lowest elevation interval in which minimum annual snow cover exceeds 50%. This ranges from about 5,500 metres above sea-level at the equator down to sea-level at about 70 degrees N&S latitude, depending on regional temperature amelioration effects. Permafrost then appears at sea-level and extends deeper below sea-level pole-wards.

As most of the Greenland and Antarctic ice sheets lie above the snowline and/or base of the permafrost zone, they cannot melt in a timeframe much less than several millennia; therefore it is likely that they will not contribute significantly to sea-level rise in the coming century. They can however do so through acceleration in flow and enhanced iceberg calving.

Climate changes during the 20th century are estimated from modelling studies to have led to contributions of between –0.2 and 0.0 mm/yr from Antarctica (the results of increasing precipitation) and 0.0 to 0.1 mm/yr from Greenland (from changes in both precipitation and runoff).

Estimates suggest that Greenland and Antarctica have contributed 0.0 to 0.5 mm/yr over the 20th century as a result of long-term adjustment to the end of the last ice age.

I use the wiki reference below because it captures a lot of data on one page.

http://en.wikipedia.org/wiki/Sea_level_rise#Glaciers_and_ice_caps
 
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  • #5
daniel_i_l said:
If you have ice cubes in a glass of water and they melt the level of the water goes down. Why are glaciers in the ocean different?
The level does not go down, it remains constant. The reason being that the floating ice has already displaced its weight in unfrozen water. If the level goes down in a glass it is because the ice is being held under water by friction against the sides of the glass.
 
  • #6
Farsight said:
The ice that might melt and cause a rise in sea levels is sitting on land, in Antarctica and Greenland.
There is no doubt anymore that the ice is melting in Antartica and Greenland.

http://news.bbc.co.uk/1/hi/world/europe/3922579.stm

In 2001 NASA scientists published a major study based on observations by satellite and aircraft.

It concluded that the margins of the Greenland ice-sheet were dropping in height at a rate of roughly one metre a year.

Now, amid some of the most hostile conditions anywhere on the planet, Carl Boggild and his team have recorded falls as dramatic as 10 metres a year - in places the ice is dropping at a rate of one metre a month.

http://www.washingtonpost.com/wp-dyn/content/article/2006/03/02/AR2006030201712.html

The new Antarctic measurements, using data from two NASA satellites called the Gravity Recovery and Climate Experiment (GRACE), found that the amount of water pouring annually from the ice sheet into the ocean -- equivalent to the amount of water the United States uses in three months -- is causing global sea level to rise by 0.4 millimeters a year. The continent holds 90 percent of the world's ice, and the disappearance of even its smaller West Antarctic ice sheet could raise worldwide sea levels by an estimated 20 feet.
 
  • #7
What's the plausibility of just pumping and storing water onto a portion of Antarctica that never gets to be above freezing? That has to be cheaper and more feasible than relocating all of the cities near the ocean. Has anyone seen a proposal to do anything like this?
 
  • #8
Skyhunter said:
…There is no doubt anymore that the ice is melting in Antartica and Greenland…
…not a recent phenomenon caused by global warming…

“Greenland's glaciers have been shrinking for the past century, according to a Danish study, suggesting that the ice melt is not a recent phenomenon caused by global warming

http://www.breitbart.com/news/2006/08/21/060821191826.o0mynclv.html [Broken]
 
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  • #9
mhalavo said:
What's the plausibility of just pumping and storing water onto a portion of Antarctica that never gets to be above freezing? That has to be cheaper and more feasible than relocating all of the cities near the ocean. Has anyone seen a proposal to do anything like this?

I'm afraid that it's not feasible. Ice sheets are dynamic and do flow. Increasing the height of the ice sheet will cause increased outflow sideways and the ice gets back into the sea eventually.

Anyway, the observations of Grace are consistent with Antarctic cooling. The amount of precipitation on the summit of Antarctica is shown to be rather strongly correlated with temperature according to the work of Michel Helsen including his PhD thesis on his site. Consequently, when it's colder, the snow accumulation decreases but the outflow sideways does not react immediately due to inertia.

So we have to wait until Antarctica warms too, then the accumulation will pick up again, lowering the sea levels.
 
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  • #10
I posted this a few months ago somewhere here.
Mk said:
As the news media often does, highly complicated matters are over-simplified to give viewers and readers easy-to-digest meals that do not require much thinking—this is where the problem inlies in understanding of sea level.
Mean sea level (MSL) is the average (mean) height of the sea, with reference to a suitable reference surface. Defining the reference level (Permanent Service for Mean Sea Level), however, involves complex measurement, and accurately determining MSL can prove difficult. Finding the MSL change involves comparing the local height of the mean sea surface with a "level" reference surface or datum, called the geoid. In a state of rest with absence of external forces (totally stagnant water), the mean sea level would be the same at every point on the Earth. The geoid would only deviate from the perfect sphere in this theoretical model with local differences in MSL from local deviations in the Earth's gravitational field. In reality, due to currents, air pressure variations, temperature variations, salinity variations, etc., this does not occur, and prevents certain verifiable long term averages from being calculated. The location-dependent, but persistent in time, separation between mean sea level and the geoid is referred to as "stationary sea surface topography," which varies globally by ±2 meters, further offsetting the MSL.

Traditionally, one must have had to process sea-level measurements to take into account the effect of the 228-month Metonic cycle and the 223-month eclipse cycle on the tides (both having to do with the moon's effect on sea level). MSL never remains constant over the surface of the entire earth. For instance, MSL at the Pacific end of the Panama Canal stands approximately 20 centimeters (0.6 ft) higher than at the Atlantic end.

Despite the difficulties, aviators flying under instrument flight rules (IFR) must have accurate and reliable measurements of their altitudes above (or below, for airports such as in the Netherlands) local MSL, and the altitude of the airports where they intend to land.

Several terms are used to describe the changing relationships between sea level and dry land. When the term "relative" is used, it connotes change that is not attributed to any specific cause. The term "eustatic" refers to changes in the amount of water in the oceans, usually due to climatic changes. The melting of glaciers at the end of ice ages is an example of eustatic sea level rise. The term "isostatic" refers to changes in the land level, of land masses due to thermal buoyancy or tectonic effects and implies no real change in the amount of water in the oceans, although isostatic changes change the MSL because it is relative to the land. The subsidence of land due to the withdrawal of groundwater is an isostatic cause of relative sea level rise. Paleoclimatologists can track sea level by examining the rocks deposited along coasts that are very tectonically stable, like the east coast of North America. Areas like volcanic islands often experience relative sea level rise as a result of isostatic cooling of the rock which causes the land to sink.
 
  • #11
Andre said:
I'm afraid that it's not feasible. Ice sheets are dynamic and do flow. Increasing the height of the ice sheet will cause increased outflow sideways and the ice gets back into the sea eventually.

Isn't that what would happen naturally anyway if precipitation begins to accelerate on Antarctica? Couldn't it buy us as much time as if nature deposited the snow there... until "whatever" occurs that will send us into the next ice age.
 
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  • #12
mhalavo said:
Isn't that what would happen naturally anyway if precipitation begins to accelerate on Antarctica? Buying us as much time as if nature deposited the snow there... until "whatever" occurs that will send us into the next ice age.

"Would happen naturally?" Does happen naturally --- ice flows. It's part of the hydrologic cycle.
 
  • #13
Bystander said:
"Would happen naturally?" Does happen naturally --- ice flows. It's part of the hydrologic cycle.

I understand it happens naturally. I was just questioning why ice/snow placed there by man would suffer a fate different than if it was placed there naturally.

i.e. it could buy us many, many years...
 
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  • #14
Anyway, even if the sea level rise would persist, it still may be not feasible. Any idea what 1 mm eustatic sea level rise would require for energy to be spend to transport it to central Antarctica from sea level to three kilometers elevation over a distance of a few thousand kilometers. And expect it to be ice after a few hours at -60C.
 
  • #15
Regional warming and regional cooling

Snow in South Africa. Last time this happened was 25 years ago only an inch or so. This time its more like a few feet.

http://theworldnow.wordpress.com/2006/08/07/flooding-and-snow-take-south-africa/

Is it possible that North Americans are egocentric enough to view "global climate" as pertaining only to those areas that influence North American markets, citizens and industry? Meanwhile the "globe" that is our planet maintains a balance of temperature and weather through microclimates and regional shifts in weather patterns.
 
  • #16
mhalavo said:
I understand it happens naturally. I was just questioning why ice/snow placed there by man would suffer a fate different than if it was placed there naturally.

i.e. it could buy us many, many years...

You wanta pump 10,000 tons of sea water per second a km in the air at a minimum energy expenditure rate of 100 GW (total power for U. S.) to prove that ice flows off continental margins at a rate proportional to its deposition rate, go for it --- it's an expensive experiment given that no one knows what the "natural" rate of sea level rise is at the moment (we're only 12-15 ka out of the last ice age, and sea level is still recovering from that), and given the Corps of Engineers experience with controlling beach erosion, and given that it ain't all that likely to work as far as stabilizing sea level at some arbitrarily decided point.
 
  • #17
Andre said:
Anyway, even if the sea level rise would persist, it still may be not feasible. Any idea what 1 mm eustatic sea level rise would require for energy to be spend to transport it to central Antarctica from sea level to three kilometers elevation over a distance of a few thousand kilometers. And expect it to be ice after a few hours at -60C.


It would take much less energy and money than would be required to relocate everyone endangered by the encroaching sea level...
 
  • #18
Bystander said:
You wanta pump 10,000 tons of sea water per second a km in the air at a minimum energy expenditure rate of 100 GW (total power for U. S.) to prove that ice flows off continental margins at a rate proportional to its deposition rate, go for it --- it's an expensive experiment given that no one knows what the "natural" rate of sea level rise is at the moment (we're only 12-15 ka out of the last ice age, and sea level is still recovering from that), and given the Corps of Engineers experience with controlling beach erosion, and given that it ain't all that likely to work as far as stabilizing sea level at some arbitrarily decided point.

If we had a pump that could keep up with the sarcasm you're putting out we could use that... I just posed a question about a possible engineering solution to a possible future problem.
 
  • #19
mhalavo said:
If we had a pump that could keep up with the sarcasm you're putting out we could use that... I just posed a question about a possible engineering solution to a possible future problem.

Do the math --- "why can't we put purple alligators in the sewers" type proposals are wastes of time --- think before asking questions, and you won't be getting answers you deem "sarcastic."
 
  • #20
nannoh said:
Snow in South Africa. Last time this happened was 25 years ago only an inch or so. This time its more like a few feet.

http://theworldnow.wordpress.com/2006/08/07/flooding-and-snow-take-south-africa/

Is it possible that North Americans are egocentric enough to view "global climate" as pertaining only to those areas that influence North American markets, citizens and industry? Meanwhile the "globe" that is our planet maintains a balance of temperature and weather through microclimates and regional shifts in weather patterns.
Last year in June I saw snow in Somalia. I don't think there are any mountains high enough for that to even happen. The hole pace is desert or arid/semiarid.
 
  • #21
mhalavo said:
It would take much less energy and money than would be required to relocate everyone endangered by the encroaching sea level...
Unless it happened too slow to really notice anything.
 
  • #22
mhalavo said:
If we had a pump that could keep up with the sarcasm you're putting out we could use that... I just posed a question about a possible engineering solution to a possible future problem.
It would be far cheaper, as well as more feasible, to build levees like the ones in Holland, than to relocate cities or to try pumping sea water to the center of Antarctica.
 
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  • #23
GENIERE said:
…not a recent phenomenon caused by global warming…
Or is it?

The shrinking of the glaciers since the 19th century is "the result of the atmosphere's natural warming, following volcanic eruptions for example and greenhouse gases, created by human activities, which have aggravated the situation further," he said.
http://www.breitbart.com/news/2006/08/21/060821191826.o0mynclv.html [Broken]

I guess we will have to see the whole study before we jump to conclusions based on the press release.
 
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  • #24
Mk said:
Last year in June I saw snow in Somalia. I don't think there are any mountains high enough for that to even happen. The hole pace is desert or arid/semiarid.

If you take a look at the world map you can see what we think of as the normal distribution of cool vs warm areas and where they transit into one another. There appears to be a trend where Antartica is warming while just on the other side of the south pole, S Africa and related regions are cooling. It is similar if you look at the locations of the coolest temperatures near the artic circle and the locations of unusual warming in neighboring regions.

Here's an excellent overview of global temperatures (however I didn't find an explanation of method of data compilation)

http://members.chello.nl/~a.horlings/nat-wea.html
 
  • #25
Andre said:
Anyway, the observations of Grace are consistent with Antarctic cooling. The amount of precipitation on the summit of Antarctica is shown to be rather strongly correlated with temperature according to the work of Michel Helsen including his PhD thesis on his site. Consequently, when it's colder, the snow accumulation decreases but the outflow sideways does not react immediately due to inertia.

So we have to wait until Antarctica warms too, then the accumulation will pick up again, lowering the sea levels.
Except Antartica is already warming. At least according to the http://www.antarctica.ac.uk/Key_Topics/IceSheet_SeaLevel/index.html.

Over the past 50 years, the west coast of the Peninsula has been one of the most rapidly-warming parts of the planet, with annual mean temperatures rising by nearly 3°C and the largest warming occurring in the winter season. This is approximately 10 times the mean rate of global warming, as reported by the Intergovernmental Panel on Climate Change (IPCC). Upper ocean temperatures to the west of the Peninsula have also increased by over 1°C since 19554. The east coast of the Peninsula has warmed more slowly and here the largest warming has taken place in summer and autumn.

Analysis of weather balloon data collected over the past 30 years has shown that the Antarctic atmosphere has warmed below 8 km and cooled above this height. This pattern of warming in the troposphere and cooling in the stratosphere is seen globally and is the expected signature of increases in greenhouse gasses, such as carbon dioxide. However, the 30-year warming at 5 km over the Antarctic during winter (0.75°C) is over three times the average rate of warming at this level for the globe as a whole.

East Antarctica
Despite very low rates of snowfall and low ice-flow rates, the huge area of the East Antarctic ice sheet means that even tiny changes in the thickness in this region could have a substantial effect on sea level rise. Recent evidence from satellite altimeters suggests that over the last decade there has been a thickening of a couple of centimetres per year and a little more in some limited regions. Debate concerning the exact distribution and magnitude of this change continue. It is possible that this observation represents the emergence of a long-predicted consequence of anthropogenic climate change, that the rate of snow-fall over Antarctica will increase, and act to slow the rate of sea level rise. However, even if this is the case, and if climate change continues in future, current climate models predict that the increase in snowfall over East Antarctica could only marginally reduce the rate of global sea level rise
 
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  • #26
Here is a collection of weather reports from around our planet specifically reporting record breaking cold snaps and downpours in places that rarely, in recorded history, have experienced these sorts of conditions. Also included are some reports about surging (expanding) glaciers and how Antartica continues to experience accumulating snowfall and thickening glaciation in its eastern region.

_________________________________________________


16 Aug 06 In the northern part of Eastern Cape, cars and lorries were left stranded as the heavy snow set in, forcing authorities to launch a rescue mission for the stranded drivers. There are now fears that the roofs of houses and buildings would collapse under the weight of the snow in several towns across the province.

This wintry blast is not uncommon in South Africa at this time of year, but it is the second significant storm to hit this region in a month. Two weeks ago an intense area of low pressure caused a lot of destruction in Lesotho and Eastern Cape.

Meanwhile south-eastern parts of Australia have also been battered by severe weather in the past few days. A powerful storm packed with thunder, hail and strong winds passed through Sydney during the early hours of Wednesday morning.

The storm intensified as it approached Sydney and generated an intense amount of hail. The hail was not particularly large, just pea sized, therefore it did not cause too much damage, but it was the amount of hail which was of surprise. The streets were left blanketed by the hail, and looked as though a snow storm had passed through. Entire areas were left white during a very small space of time and the hail was ankle deep in some places.

http://www.bbc.co.uk/weather/world/news/16082006news.shtml[/URL]

One month’s rain in 12 hours - [b]14 Aug 06[/b]
Much of Europe has experienced heavy rain over the last few days,
from Romania and Bulgaria to the UK.

Split, Croatia, received 48mm (1.89 inches) of rain in 12 hours, more
than its average for the entire month of August of 43mm (1.69 inches).
Herceg Novi in Montenegro received 60mm (2.36 inches) in the same
12-hour period, while Pescara, Italy received 32mm (1.26 inches), well
over half the monthly average.

In the UK, Lowestoft in Suffolk received 35.9mm (1.41 inches) of rain
in 24 hours, close to the monthly average for August of 37.1mm (1.46 inches).
[PLAIN]http://www.bbc.co.uk/weather/world/news/14082006news.shtml[/URL]



Record cold in South Africa - [b]3 Aug 06[/b] - Temperatures dropped to record lows
for August as snow fell in Johannesburg, and deep snow forced mountain passes to
close. Local residents say that it is an unusually severe winter.

The city saw a high of 7 degrees Celsius (44 Fahrenheit) on Wednesday -- the lowest
daily high recorded in August -- while overnight temperatures dropped well below freezing
in some partsof the country. Colder temperatures are expected this weekend.
[PLAIN]http://news.yahoo.com/s/nm/20060803/sc_nm/weather_safrica_dc_1[/URL]



Record low temperatures in New Zealand - [b]8 Jul 06[/b] - New Zealand has endured record-low
temperatures, unusual amounts of snow, and heavy rain over the last few months.

Storms battered the lower part of North Island last week. Days of torrential rain caused widespread
flooding, the worst hit being Southern Wairarapa and South Taranaki. A bridge fell into the swollen
Mangawhero River in the wake of the storm, virtually isolating a small, rural community that relies
heavily on the bridge.

Meanwhile, the South Island has been hit by heavy snow storms over the last month or so. The very
cold weather has been causing major problems for the June crops. Some vegetables are more than
four times their normal price as a result.
[PLAIN]http://www.bbc.co.uk/weather/world/news/09072006news.shtml[/URL]





(What is an "Ice Age Rain"?)

Ice-Age Rains Continue in China - [b]4 Jul 06[/b] - Torrential rains continues in central and eastern

China. Millions of people’s homes have been destroyed by heavy rain. At least 349 people died

in weather-related disasters in June, while 99 others are still missing, Xinhua news agency quoted

the China Meteorological Administration (CMA) as saying. Economic losses are estimated at

$2.53 billion from the disasters.

[PLAIN]http://www.sabcnews.com/world/asia1pacific/0,2172,130538,00.html[/URL]



Harshest frosts in 20 years in Australia- [b]26 Jun 06[/b] - Orange prices are set to rise as
the harshest frosts in 20 years in two of Australia's main orange-growing regions cause havoc
for the citrus industry.

Navel orange exports to the lucrative US and China markets would drop by between 10 and 40
percent, Australian Citrus Growers' president Mark Chown said today. Some orange growers could
be forced from the industry, he said.
[PLAIN]http://www.news.com.au/story/0,10117,19591169-421,00.html[/URL]



New Zealanders have never seen snow like this - [b]23 Jun 06[/b] - Napier police are advising
motorists not to expect the Napier-Taupo Highway to open on Friday, with snow continuing
to fall on the road. A spokesperson says a large number of vehicles are lining up at Eskdale
in the hope the road may open. Police and the army are currently trying to clear the road so
stranded vehicles can be returned to their owners.

Although freight and passenger trains are still operating through the central North Island snow,
Toll Holdings' group general manager, Gary Taylor, says their engineers report never seeing
snow like it in the region.
[url]http://tvnz.co.nz/view/page/411319/763217[/url]



Record cold in Australia - [b]18 Jun 06[/b] - The city of Perth recorded its coldest night on
record Friday night, as temperatures dropped below zero.

The average daily low in June in Perth is 10.1C (50.2F), and the average high is
18.3C (64.9F). Not since records began has the mercury dropped below zero during
any month of the year. But it dipped to minus 0.6C (30.9F) Friday night, giving Perth
its first official freeze.

A record low was also recorded at Jandakot of minus three degrees.

The cold snap also saw several records broken in towns in the southwest. Collie reported
minus 5.8 degrees, its all time lowest minimum. In Bridgetown, the temperature fell to
minus five degrees which is also a record low.
(Thanks to A.C. Frost in Australia for this info.)
[PLAIN]http://www.bbc.co.uk/weather/world/news/18062006news.shtml[/URL]



Heaviest snowfall in New Zealand in 50 years
[b]12 June 06[/b] - Hundreds of thousands of New Zealanders were without
power today as chaotic winter weather whipped up destructive gales and
dumped snow across the country.

The Canterbury region was worst hit with roads, schools and businesses
closed and farmland and towns blanketed in up to a three feet of snow. It
was described in some areas as the heaviest fall in 50 years. Even the
Mt. Hutt ski field was off limits to skiers.

Christchurch airport was shut down in the morning before snow was
cleared from the runway.
Sydney Morning Herald
http://www.smh.com.au/news/world/gales-snow-tornado-chaotic-weather-in-nz/2006/0 6/12/1149964463334.html



Recently surging glaciers and snow accumulation

http://www.gi.alaska.edu/~truffer/McGinnisSurge/ (pics)

The existing Halley base - the fifth to occupy the spot since 1956 - has been a tremendous success.

It, too, has been jacked up on extendable legs to keep it above an accumulated snowfall of 1.5m (5ft) a year (the previous four bases were all buried).

[url]http://news.bbc.co.uk/2/hi/science/nature/4693409.stm[/url]



East Antartica Puts On Weight

[url]http://www.nature.com/news/2005/050516/full/050516-10.html[/url]



(Warming Is Blamed for) Antarctica's Weight Gain

By KENNETH CHANG
Published: May 20, 2005
The eastern half of Antarctica is gaining weight, more than 45 billion tons a year, according to a new scientific study.

Data from satellites bouncing radar signals off the ground show that the surface of eastern Antarctica appears to be slowly growing higher, by about 1.8 centimeters a year, as snow and ice pile up.



[url]http://www.nytimes.com/2005/05/20/science/20ICE.html[/url]



Satellites show overall increases in Antarctic Sea Ice Cover Around Antarctica. Claire Parkinson of NASA's Goddard Space Flight Center found that sea ice seasons have lengthened by at least one day per year over an area of 2.16 million square miles (about 3/4 of the size of the continental United States). This is roughly twice as large as the area where sea ice seasons have shortened by at least one day per year.

Sea ice now covers the area for three weeks longer per year than it did 21 years ago. Annals of Glaciology, Aug 22, 2002 See also [PLAIN]www.gsfc.nasa.gov/topstory/20020820southseaice.html[/URL]



GREENLAND
Greenland glacier advancing 7.2 miles per year! The BBC recently ran a documentary, The Big Chill, saying that we could be on the verge of an ice age. Britain could be heading towards an Alaskan-type climate within a decade, say scientists, because the Gulf Stream is being gradually cut off. The Gulf Stream keeps temperatures unusually high for such a northerly latitude.
One of Greenland’s largest glaciers has already doubled its rate of advance, moving forward at the rate of 12 kilometers (7.2 miles) per year. To see a transcript of the documentary, go to



[url]http://www.bbc.co.uk/science/horizon/2003/bigchilltrans.shtml[/url]
 
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What is global warming?

Global warming is the long-term increase in Earth's average surface temperature caused by human activities, such as burning fossil fuels and deforestation. These activities release greenhouse gases into the atmosphere, trapping heat and causing the Earth's temperature to rise.

How does global warming lead to rising water levels?

Global warming causes the Earth's polar ice caps and glaciers to melt, which adds more water to the oceans. Additionally, as the Earth's temperature rises, the water in the oceans expands, contributing to rising sea levels.

What are the consequences of rising water levels?

Rising water levels can lead to coastal flooding, erosion, and saltwater intrusion into freshwater sources. This can have devastating effects on coastal communities, wildlife, and ecosystems. It also increases the risk of extreme weather events, such as hurricanes and storms, which can cause further damage.

How do we know that global warming is causing rising water levels?

Scientists use a variety of methods to monitor and measure global warming and its effects on the environment. This includes satellite data, temperature records, and sea level measurements. The data consistently shows that the Earth's temperature is rising and that sea levels are also increasing.

What can be done to address rising water levels caused by global warming?

To address rising water levels, we need to reduce our greenhouse gas emissions by transitioning to clean and renewable energy sources. We also need to protect and restore natural habitats such as wetlands and mangrove forests, which act as natural buffers against rising sea levels. Additionally, adapting to the effects of rising water levels, such as building sea walls and implementing flood management strategies, is crucial for the protection of communities and infrastructure.

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