Are sea levels rising?

[gib65]

One of the predictions of GW is that the polar ice caps will melt and cause sea levels to rise. Have they been rising?

[insane_alien]

http://en.wikipedia.org/wiki/Current_sea_level_rise

 

yep, at about 2mm/year

 

i know its wikipedia and lots of people are likely to go 'its only wikipedia, half the stuffs wrong anyway' but this article is quite well referenced if you care to look.

[melanie tan]

If you watched the episode on the National Geographic Channel, they tackled about the melting of the polar caps of the earth. And the result of this, rising of water and many places would be drowned

[Pangloss]

Melanie, I think your post was placed in moderated status because of the mention of Nat Geo channel, but it's visible to everyone now. Sorry about that.

[jackson33]

Melanie, I think your post was placed in moderated status because of the mention of Nat Geo channel, but it's visible to everyone now. Sorry about that. [/Quote]

 

Pangloss; Interesting, who is authorized to place post on "moderated status" and how would she know it was???

 

However it may be for another reason...First post...and probably just not aware of the rules.

 

hi everyone, Melanie is on board. Glad to join this forum, hope to learn from you guys and learn from me too. In case you are looking for a an effective skin tanning medicine, there is a online retailer of it., Try to visit GM2labs..^^[/Quote]

 

 

If you watched the episode on the National Geographic Channel, they tackled about the melting of the polar caps of the earth. And the result of this, rising of water and many places would be drowned [/Quote]

 

Think, at a later date it was determined 'Polar Bears' can actually swim up to 75 miles, those images were from little ice bergs (not polar ice) and that PB have been increasing in numbers. Also we're now being told, Ice has been reforming, this year.

 

Second, as an occasional poster, welcome to the forum. If your interested in "learning", think you might be, they do have a rule against promoting products, even not your own.

 

One of the predictions of GW is that the polar ice caps will melt and cause sea levels to rise. Have they been rising?[/Quote]

 

Gib, as I_A has said, they may be rising, but if so, very slightly. There are figures, if all the ice melted on the North Pole, rises would be minimal, since those glaciers are for the most part already in the water. The South Pole, is however, for the most part on land and could add to ocean levels. With average temperatures at the SP, well below -0-, we're a long way from seeing any major melting. AGW or GW are talking in terms of a degree or so per decade.

[Sisyphus]

Interesting, who is authorized to place post on "moderated status" and how would she know it was???

 

We have software that automatically takes posts that it deems probable spam and keeps them invisible until a moderator either lets them through or deletes them. It actually works quite well, catching probably 95%, with only the occasional false positive like this one.

[jackson33]

Gib, had to go for awhile and didn't have time to look up a reference. This pretty well fits your question and my, from memory reply.....

 

One unmentioned item, at this site, is the natural run off from rivers into the oceans, shoreline erosion and volcano activity, adding to non water matter (fill) in the oceans and can be substantial.

 

You may have heard about global warming. It seems that in the last 100 years the earth's temperature has increased about half a degree Celsius. This may not sound like much, but even half a degree can have an effect on our planet. According to the U.S. Environmental Protection Agency (EPA) the sea level has risen 6 to 8 inches (15 to 20 cm) in the last 100 years (see How do they measure sea level?).

The main ice covered landmass is Antarctica at the South Pole, with about 90 percent of the world's ice (and 70 percent of its fresh water). Antarctica is covered with ice an average of 2,133 meters (7,000 feet) thick. If all of the Antarctic ice melted, sea levels around the world would rise about 61 meters (200 feet). But the average temperature in Antarctica is -37°C, so the ice there is in no danger of melting. In fact in most parts of the continent it never gets above freezing.

 

At the other end of the world, the North Pole, the ice is not nearly as thick as at the South Pole. The ice floats on the Arctic Ocean. If it melted sea levels would not be affecter*d.[/Quote]

 

http://www.howstuffworks.com/question473.htm

 

 

 

We have software that automatically takes posts that it deems probable spam and keeps them invisible until a moderator either lets them through or deletes them. It actually works quite well, catching probably 95%, with only the occasional false positive like this one.[/Quote]

 

 

Sisyphus; Makes sense to me, seems Pangloss was just not aware of the first post. In my mind I could see every post I've ever made going on "moderated status", accounting for so many moderator replies, the very reason I am here this moment, not having referenced an opinion...

[Tau Meson]

Think, at a later date it was determined 'Polar Bears' can actually swim up to 75 miles, those images were from little ice bergs (not polar ice) and that PB have been increasing in numbers. Also we're now being told, Ice has been reforming, this year.

 

Do you have a source for this? The data does not seem to agree with you, as is shown here:

 

 

It has been decreasing steadily since 1979 per year. The fact that it reforms in the winter doesn't matter, we are looking at the possibility of no summer ice in the next few years.

 

As for the polar bears, it doesn't really matter if they can swim long distances, the warmer waters make it harder for them to live and find food. If all the ice melts, they are as good as extinct.

 

 

Gib, as I_A has said, they may be rising, but if so, very slightly. There are figures, if all the ice melted on the North Pole, rises would be minimal, since those glaciers are for the most part already in the water.

 

The North Pole is a problem too. It is not necessarily the melting of the Arctic Ocean that we are worried about, but the glaciers and ice in Greenland. If that melts, we would see dramatic increases in sea levels. Here is a basic overview of how much they change per year:

 

 

The South Pole, is however, for the most part on land and could add to ocean levels. With average temperatures at the SP, well below -0-, we're a long way from seeing any major melting. AGW or GW are talking in terms of a degree or so per decade.

 

The whole South Pole doesn't have to melt for it to be a major problems. In fact, the average temperature of the South Pole doesn't have to rise by that much. Even if only the edges melt, that alone would cause quite a bit of coastal flooding problems. One of the major concerns is the Ross Ice Shelf, if that melts, you are looking at up to an increase of sea levels by 5 meters.

[jackson33]

The whole South Pole doesn't have to melt for it to be a major problems. In fact, the average temperature of the South Pole doesn't have to rise by that much. Even if only the edges melt, that alone would cause quite a bit of coastal flooding problems. One of the major concerns is the Ross Ice Shelf, if that melts, you are looking at up to an increase of sea levels by 5 meters.[/Quote]

 

Tau; You show on line, so want to get off a quick reply. I'll come back at you tomorrow on the rest, you made some valid comments, but on the above, the article I offered (not me) said a total SP melt down would raise ocean levels, think 60m or so, so obviously any extensive melt down would raise sea levels.

[scalbers]

GRACE and IceSats satellites are documenting accelerating melting of Greenland and Iceland ice sheet this past decade. This may be contributing to an increase of the sea level rise rate to 3mm/yr (up from the 2mm/yr average in the 20th century).

[jackson33]

Tau Meson quotes;

It has been decreasing steadily since 1979 per year. The fact that it reforms in the winter doesn't matter, we are looking at the possibility of no summer ice in the next few years. [/Quote]

 

Arctic is not much cooler, than many land areas near or above the arctic circle. Whether you want to blame 'Ocean Oscillation', 'trade winds', 'Carbon Deposits' or when high barometric pressures exist (current problem, driving coldest weather south), higher temperatures are going to melt ice, further back during some periods, than others, during the summer. I seriously doubt, there will be "no sumer ice" for a good many years, if for, or the foreseeable future. In the winter, never IMO.

 

In January and February, the average temperature up there hovers around a numbing -29°F / -34°C.

The temperature averages below freezing year-round, with an average annual temperature of only -14°C / 7°F.

If you think you could bask in the summer sunshine, forget it. Summer highs average only -1.5°C / 29°F! [/Quote]

 

http://www.athropolis.com/arctic-facts/fact-arctic-cold.htm

 

Where I live or anywhere on the planet, a 10-20 degree temperature deviation from the recorded normal are a common fact, sometimes for weeks on end. Guessing an average of 29F, would indicate at least 35/40F, during the Arctic's 24 Hour sunshine 2/3 month summer.

 

As for the polar bears, it doesn't really matter if they can swim long distances, the warmer waters make it harder for them to live and find food. If all the ice melts, they are as good as extinct. [/Quote]

 

The apparent consensus is, Polar Bears cannot adapt to change, which I disagree with. They have been around at least 100,000 years, no doubt adjusting to many changes in that time. Nothing will happen to them if and it often does in many places, if the "ice melts". They MAY be less comfortable...but could adapt as they no doubt have before....

 

The polar bear is found throughout the Arctic Circle and adjacent land masses . Due to the absence of human development in its remote habitat, it retains more of its original range than any other extant carnivore.[21] While they are rare north of 88°, there is evidence that they range all the way across the Arctic, and as far south as James Bay in Canada. [/Quote]

 

http://en.wikipedia.org/wiki/Polar_bear

 

They don't need to swim that far, 75-100 miles is a pretty long distance. They primary pray are seals and most PB, will follow or migrate with their food supply.

 

Annual ice contains areas of water that appear and disappear throughout the year as the weather changes. Seals migrate in response to these changes, and polar bears must follow their prey.[28] In Hudson Bay, James Bay, and some other areas, the ice melts completely each summer (an event often referred to as "ice-floe breakup"), forcing polar bears to go onto land and wait through the months until the next freeze-up.[28] In the Chukchi and Beaufort seas, polar bears retreat each summer to the ice further north that remains frozen year-round.[/Quote] Same site as above.

 

You didn't question PB population increasing, but if you link their extinction to AGW, opposed to over hunting, how could it be there are currently 25,000 compared to an estimated 5,000 in 1950?

 

"In the 1950s the polar bear population up north was estimated at 5,000. Today it's 20- to 25,000, a number that has either held steady over the last 20 years or has risen slightly. In Canada, the manager of wildlife resources for the Nunavut territory of Canada has found that the population there has increased by 25 percent." [/Quote]

 

http://www.polarbearsinternational.org/ask-the-experts/population/

 

The North Pole is a problem too. It is not necessarily the melting of the Arctic Ocean that we are worried about, but the glaciers and ice in Greenland. If that melts, we would see dramatic increases in sea levels. [/Quote]

 

Sure, as temperatures rise, ice/snow packs at higher elevations are going to melt. Tibet, is not exactly near one of the poles....But again, has this ever happened before?

 

Throughout India, China, and Nepal, some 15,000 glaciers speckle the Tibetan Plateau, some of the highest land in the world. There, perched in thin, frigid air up to 7,200 meters (23,622 feet) above sea level, the ice might seem secluded from the effects of global warming.[/Quote]

 

http://dsc.discovery.com/news/2008/11/24/tibet-glaciers-warming.html