The Vanishing of the Arctic Ice Cap
By Eric McLamb
Not only is the Arctic ice cap shrinking, it is shrinking at a pace that places its disappearance two to three decades ahead of the gloomiest previous forecasts. It is now generally predicted that the Arctic ice cap will totally disappear in 20 - 25 years, leaving the Arctic Ocean totally free of summer ice as early as the summer of 2030. Some scientists even predict that Arctic summer sea ice will totally disappear as early as 2015. The previous most dismal prediction of the Intergovernmental Panel on Climate Change had the Arctic ice cap vanishing by the year 2050.
The Arctic ice cap reached its smallest extent ever in 2007 (above, top), about 50 percent of its size in the 1950s. The image beneath it shows the ice cap’s average area in 1979-1981. (NASA images)
Scientists have long known that Earth’s northern (Arctic) and southern (Antarctic) ice caps would be the first harbingers of global warming, and now we are seeing it. Even though the Arctic ice cap has not yet shrunken quite as much this summer as it did in the summer of 2007 when it reached its smallest size ever, it has lost about 50 percent of its volume and coverage since the 1950s when ship and aircraft records were used to gather Arctic ice data instead of satellites. Since 1979, according to the National Oceanic and Atmospheric Administration (NOAA), the rate of sea ice decline has been more than 10 percent per decade. The most dramatic losses in sea ice cover have taken place since 2003.
The smallest extent ever recorded of the Arctic ice cap was in the summer of 2007 at 1.6 million square miles. This is down from three million square miles in 1980, a 47.1 percent loss of sea ice. The previous record low was set in the summer of 2005 when the ice extent dropped to 2.05 million square miles.
The Arctic Ice Cap Is Also Thinning
The Arctic ice cap’s area of coverage is not only shrinking. It is also getting thinner. It occurs all across the Arctic Ocean. Each year, as the cycle goes, Arctic ice freezes in the winter and reaches its maximum size, or extent, in early March and is at its smallest point in September. In 1991, the summer Arctic ice was about 10.2 feet thick (ice pack thickness is measured from sea level to the bottom of the ice pack). Since 2001, the thickest areas of Arctic ice have thinned to three feet, less than a third of the 1991 ice cap and half of its 2001 thickness. In some areas, the thickness is six inches or less. Yet, the ice above the sea level (called “freeboard”) in the spring of 2008 is about two to four inches less than it was in spring 2007.
The old ice, ice that did not melt each year, would reach 13-14 feet in thickness over large areas. Ice that forms in one winter season will reach only about three feet. Almost all of the old ice is gone.
Global Warming and Arctic Ice
Sea ice decline is aiding rising temperatures in the Arctic region because as the ice melts, more of the sun’s heat energy is absorbed by the dark ocean water rather than being reflected back into space by the ice cover. The fraction of energy reflected and absorbed by the Earth is called albedo. Click on the image to review animation of this effect. (NASA animation)
It is too simple to blame global warming for this occurrence. Earth has been going through dramatic climate changes since it formed over 4.5 billion years ago. But climate records since the 1920s tell us that the greatest cause of global warming today is the introduction of greenhouse gases to the atmosphere by human activity. Combine this with the loss of sea ice, warming Arctic land masses, and the flow of warmer ocean currents into the Arctic region and you have an area where the temperatures are rising at twice the pace it is anywhere else in the world. Just consider this: The heat energy that had been reflected back into space by the Arctic ice cap is now being absorbed by the ocean and land masses beneath where the ice previously existed.
Birth of the Arctic Ice Cap
The Arctic Ice Cap formed over the Arctic Ocean about 50 million years ago, virtually covering the entire sea with a sheet of ice. As the continents continued to move, climatic changes brought about by shifts in water and air currents caused the Earth to gradually cool down. It was formed from the fresh water run-offs of the Cenozoic Ice Age glaciers and had been stable until now. Witness the breakdown of the largest single block of ice in the Arctic, the 3,000 year-old Ward Hunt Ice Shelf. It began to break up in the year 2000 and is now totally breaking apart.
Environmental Unity
So what of it? This is where the dynamics of environmental unity come into focus. What happens with one element of our environment will impact other elements. But let’s first deal with anticipated rising sea levels as a result of the melting Arctic ice. Since most of the ice pack is already submerged in the Arctic Ocean (about 90% of the total volume) and is already displacing that volume of ocean water, there would be very little impact. The only Arctic ice that is not submerged is the very thin freeboard ice (above sea level). Even a complete melting of the Arctic ice cap would only result in a small increase in sea water level.
As the Arctic ice breaks up and recedes, a new era of commerce will open for commercial and personal shipping. But the major concern will the increase of fresh, cold water into the marine environment and into the oceanic currents carrying water into the warmer southern oceans. (NASA photo)
The major concern, however, would be the increase of fresh, cold water into the marine environment. This would alter ecosystems and the food chain dependent on the saline waters and would funnel more cold water into the oceanic conveyer belt. As a result, you would see a global climate change due to the introduction of the additional cold water into the southern oceans, and you would see a displacement of plant and animals species dependent on the more saline ecosystems. Some animal species will, of course, retreat to the land-based ecosystems. New and migrating marine species would flourish in the nutrient rich waters of the Arctic.
Consider shipping… as the ice cap recedes, shipping lanes between the Atlantic and Pacific Oceans will become available to commerce and passenger transportation, opening up substantial economic advantages. But then again, at what cost? Can we reverse the global warming patterns that would help restore and maintain the Arctic ice for another 50 million years? Do we want to? Can we let it revert back to an ice-less ocean (if we have a choice), as it was before it formed 50 million years ago? Although most scientists predict the Arctic ice cap will be totally gone in the 21st century, there are still some who say it does not have to be that way. Adaptations are part of the continuing circles of life, and life will adapt.
But on the other end of the planet…. that’s different story. Coming soon… The Antarctic Ice Deluge.
August 5, 2008
--------------------------------------------------------------------------------
Did you know....?
There is no land anywhere underneath the Arctic Ice Cap… never has been. It’s all ocean.
The warmest month in the Arctic is July when the mean temperature is 32 degrees Fahrenheit. Its coldest month is February when the average temperature drops to a super frigid minus 31 degrees Fahrenheit.
Greenland, which is technically part of the continent of North America, is a Danish province that lies between the Arctic and Atlantic Oceans. It is not part of the Arctic ice cap, but it is the second largest ice body in the world just after Antarctica. It is 80 percent covered by an ice sheet covering roughly 660,000 square miles and six to about 10 feet thick. This does not include the 30-39,000 square miles of glaciers and small ice caps on its perimeter. If all of the Greenland ice were to melt, it is predicted that it would result in a global sea level rise of 23.6 feet (Wikipedia).
Global sea-level has risen about 400 feet since the peak of the last ice age about 18,000 years ago. Most of the rise occurred before 6,000 years ago. (Wikipedia)
In the summer of 2007, Russia planted its national flag on the ocean floor at the North Pole claiming roughly 460,000 square miles of Arctic waters.
By Eric McLamb
Not only is the Arctic ice cap shrinking, it is shrinking at a pace that places its disappearance two to three decades ahead of the gloomiest previous forecasts. It is now generally predicted that the Arctic ice cap will totally disappear in 20 - 25 years, leaving the Arctic Ocean totally free of summer ice as early as the summer of 2030. Some scientists even predict that Arctic summer sea ice will totally disappear as early as 2015. The previous most dismal prediction of the Intergovernmental Panel on Climate Change had the Arctic ice cap vanishing by the year 2050.
The Arctic ice cap reached its smallest extent ever in 2007 (above, top), about 50 percent of its size in the 1950s. The image beneath it shows the ice cap’s average area in 1979-1981. (NASA images)
Scientists have long known that Earth’s northern (Arctic) and southern (Antarctic) ice caps would be the first harbingers of global warming, and now we are seeing it. Even though the Arctic ice cap has not yet shrunken quite as much this summer as it did in the summer of 2007 when it reached its smallest size ever, it has lost about 50 percent of its volume and coverage since the 1950s when ship and aircraft records were used to gather Arctic ice data instead of satellites. Since 1979, according to the National Oceanic and Atmospheric Administration (NOAA), the rate of sea ice decline has been more than 10 percent per decade. The most dramatic losses in sea ice cover have taken place since 2003.
The smallest extent ever recorded of the Arctic ice cap was in the summer of 2007 at 1.6 million square miles. This is down from three million square miles in 1980, a 47.1 percent loss of sea ice. The previous record low was set in the summer of 2005 when the ice extent dropped to 2.05 million square miles.
The Arctic Ice Cap Is Also Thinning
The Arctic ice cap’s area of coverage is not only shrinking. It is also getting thinner. It occurs all across the Arctic Ocean. Each year, as the cycle goes, Arctic ice freezes in the winter and reaches its maximum size, or extent, in early March and is at its smallest point in September. In 1991, the summer Arctic ice was about 10.2 feet thick (ice pack thickness is measured from sea level to the bottom of the ice pack). Since 2001, the thickest areas of Arctic ice have thinned to three feet, less than a third of the 1991 ice cap and half of its 2001 thickness. In some areas, the thickness is six inches or less. Yet, the ice above the sea level (called “freeboard”) in the spring of 2008 is about two to four inches less than it was in spring 2007.
The old ice, ice that did not melt each year, would reach 13-14 feet in thickness over large areas. Ice that forms in one winter season will reach only about three feet. Almost all of the old ice is gone.
Global Warming and Arctic Ice
Sea ice decline is aiding rising temperatures in the Arctic region because as the ice melts, more of the sun’s heat energy is absorbed by the dark ocean water rather than being reflected back into space by the ice cover. The fraction of energy reflected and absorbed by the Earth is called albedo. Click on the image to review animation of this effect. (NASA animation)
It is too simple to blame global warming for this occurrence. Earth has been going through dramatic climate changes since it formed over 4.5 billion years ago. But climate records since the 1920s tell us that the greatest cause of global warming today is the introduction of greenhouse gases to the atmosphere by human activity. Combine this with the loss of sea ice, warming Arctic land masses, and the flow of warmer ocean currents into the Arctic region and you have an area where the temperatures are rising at twice the pace it is anywhere else in the world. Just consider this: The heat energy that had been reflected back into space by the Arctic ice cap is now being absorbed by the ocean and land masses beneath where the ice previously existed.
Birth of the Arctic Ice Cap
The Arctic Ice Cap formed over the Arctic Ocean about 50 million years ago, virtually covering the entire sea with a sheet of ice. As the continents continued to move, climatic changes brought about by shifts in water and air currents caused the Earth to gradually cool down. It was formed from the fresh water run-offs of the Cenozoic Ice Age glaciers and had been stable until now. Witness the breakdown of the largest single block of ice in the Arctic, the 3,000 year-old Ward Hunt Ice Shelf. It began to break up in the year 2000 and is now totally breaking apart.
Environmental Unity
So what of it? This is where the dynamics of environmental unity come into focus. What happens with one element of our environment will impact other elements. But let’s first deal with anticipated rising sea levels as a result of the melting Arctic ice. Since most of the ice pack is already submerged in the Arctic Ocean (about 90% of the total volume) and is already displacing that volume of ocean water, there would be very little impact. The only Arctic ice that is not submerged is the very thin freeboard ice (above sea level). Even a complete melting of the Arctic ice cap would only result in a small increase in sea water level.
As the Arctic ice breaks up and recedes, a new era of commerce will open for commercial and personal shipping. But the major concern will the increase of fresh, cold water into the marine environment and into the oceanic currents carrying water into the warmer southern oceans. (NASA photo)
The major concern, however, would be the increase of fresh, cold water into the marine environment. This would alter ecosystems and the food chain dependent on the saline waters and would funnel more cold water into the oceanic conveyer belt. As a result, you would see a global climate change due to the introduction of the additional cold water into the southern oceans, and you would see a displacement of plant and animals species dependent on the more saline ecosystems. Some animal species will, of course, retreat to the land-based ecosystems. New and migrating marine species would flourish in the nutrient rich waters of the Arctic.
Consider shipping… as the ice cap recedes, shipping lanes between the Atlantic and Pacific Oceans will become available to commerce and passenger transportation, opening up substantial economic advantages. But then again, at what cost? Can we reverse the global warming patterns that would help restore and maintain the Arctic ice for another 50 million years? Do we want to? Can we let it revert back to an ice-less ocean (if we have a choice), as it was before it formed 50 million years ago? Although most scientists predict the Arctic ice cap will be totally gone in the 21st century, there are still some who say it does not have to be that way. Adaptations are part of the continuing circles of life, and life will adapt.
But on the other end of the planet…. that’s different story. Coming soon… The Antarctic Ice Deluge.
August 5, 2008
--------------------------------------------------------------------------------
Did you know....?
There is no land anywhere underneath the Arctic Ice Cap… never has been. It’s all ocean.
The warmest month in the Arctic is July when the mean temperature is 32 degrees Fahrenheit. Its coldest month is February when the average temperature drops to a super frigid minus 31 degrees Fahrenheit.
Greenland, which is technically part of the continent of North America, is a Danish province that lies between the Arctic and Atlantic Oceans. It is not part of the Arctic ice cap, but it is the second largest ice body in the world just after Antarctica. It is 80 percent covered by an ice sheet covering roughly 660,000 square miles and six to about 10 feet thick. This does not include the 30-39,000 square miles of glaciers and small ice caps on its perimeter. If all of the Greenland ice were to melt, it is predicted that it would result in a global sea level rise of 23.6 feet (Wikipedia).
Global sea-level has risen about 400 feet since the peak of the last ice age about 18,000 years ago. Most of the rise occurred before 6,000 years ago. (Wikipedia)
In the summer of 2007, Russia planted its national flag on the ocean floor at the North Pole claiming roughly 460,000 square miles of Arctic waters.
We really have lost like the whole Polar Ice Cap...That is scary.
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