Melting ice -- a real threat to the lives and livelihood
Sunday, 17 June 2007
Ripan Kumar Biswas
PERHAPS, all concerned would be very happy, had there been no object like an iceberg. The collision of the iceberg with the Titanic -- the most luxurious vessel of its time -- in the North Atlantic Ocean on April 14, 1912 caused deaths of over 1500 people.
It is a matter of concern to think about the future of the world's coastlines in the event of the melting of the West Antarctic Ice Sheet that is projected to raise the global sea levels by as much as 20 feet. Then, the people will not have sufficient land to live.
Commemorating the World Environment Day, as we did on June 5, 2007 with the slogan "Melting Ice-a Hot Topic?" will serve no useful purpose if we do not take any step against the effects of climate change on polar ecosystems and communities and the severe adverse consequences thereof around the world.
There are a plenty of small steps that people can take to save the environment. While the eco-footprint of each step is small, thousands of people doing the same thing can make a difference.
About 20,000 years ago at the height of the Ice Age, sea levels were 400 feet lower than today and there was a lot more land to go around.
If the East Antarctic Ice Sheet melts -- and this monstrous dome will disintegrate anytime sooner or later -- it would raise the sea level around the world by as much as 200 feet.
Ice is melting everywhere -- and it is taking place at an accelerating rate. Rising global temperatures is lengthening melting seasons, thawing frozen ground, and thinning ice caps and glaciers that in some cases have existed for millennia. These changes are raising sea level faster than earlier projected by scientists, and threatening both human and wildlife populations.
The warmer water melts more sea ice, and eventually the warmer atmosphere, above the warmer water, will melt more of the ice sheets on Greenland.
Warming temperatures and more open water will pave the way for greater snowfall, making it more difficult for hunting krill, affecting nesting success. These changes are now very common to be seen in Adelie colonies on the Antarctic Peninsula.
It is thought that over 13,000 sq km of sea ice in the Antarctic Peninsula has been lost over the last 50 years.
During the last 25 years, thousands of Adelies of Humble Island, one of eight islets of Anvers Island where they have nested for some 600 years, have been declining sharply.
The world's second largest ice cap may be melting three times faster than indicated by previous measurements, according to the newly released gravity data collected by satellites.
The Greenland Ice Sheet shrank at a rate of about 239 cubic kilometers per year from April 2002 to November 2005. A team from the University of Texas at Austin in the US, reported it. In course of measurements made during the last 18 months, ice melting has appeared to accelerate, particularly in southeastern Greenland.
Satellite data show Greenland's ice has been melting at higher and higher elevations every year since 1979. A conservative estimate of annual ice loss from Greenland is 50 cubic kilometers (12 cubic miles) per year -- enough water to raise the global sea level by 0.13 millimeters a year.
Based on the observations and deliberations of 300 scientists from eight countries and six groups of indigenous people, the Arctic region, as the Arctic Council reported recently, is warming at twice the rate of the rest of the world and the sea ice that covers the Arctic Ocean is thinning, and could almost disappear in the summer months by 2100.
In addition, their other report from satellite measurements indicates that the area over which ice melts in the summer in Greenland increased 16 per cent between 1979 and 2002 and if the melting continues, sea levels would rise seven meters or so, inundating Florida, New York City, London, and Bangladesh.
Average surface temperatures in the Arctic Circle have risen by more than half a degree Celsius (0.9 degrees Fahrenheit) per decade since 1981. The extent of Arctic sea ice cover has decreased by 7.0-9.0 per cent per decade.
The Arctic melt season has lengthened by 10-17 days, shrinking the amount of ice buildup that remains from year to year and, according to the latest forecasts, the Arctic could be ice-free in the summer by the end of this century.
In 2003, Argentine glaciologists reported that the land-based glaciers, exposed by the removal of those sections, had surged rapidly into the ocean. Thus, although ice shelves are floating and do not add to sea level when they melt or break up, land-based glaciers, released by such events, will definitely add to the sea level.
Ice melting is not limited to the poles. According to glaciologist Lonnie Thompson of Ohio State University, the USA, all but 13 of the 2,000 glaciers in southeast Alaska are retreating. Montana's Glacier National Park may have no glaciers left by 2030, and the ice cap on Tanzania's Kilimanjaro may disappear completely by 2015.
By 2025, Alpine glaciers are likely to contain only half their 1970s' volume, dwindling to 5.0 per cent by the end of the century.
Millions of people living in Asia and South America rely on glacial runoff for drinking water and irrigation. If the glaciers disappear, severe water shortages are sure to follow. Meanwhile, rapidly filling glacial lakes in both the Andes and the Himalayas threaten to break their banks and flood towns below.
Asia's largest rivers, the Ganges and the Bramaputra, converge in the world's most extensive delta and flow into the Bay of Bengal. Every year, thousands of people are displaced by loss of land along these rivers, and the indications are increasing almost every day.
The one meter sea-level rise, as is generally predicted in the event of no action taking place about global warming, will inundate more than 15 per cent of Bangladesh, displacing more than 13 million people. This will adversely affect its rice cropping. Intruding water will damage the Sundarbans mangrove forest, a world heritage site.
Bangladesh's food supply is already threatened by flooding due to melting glaciers in some areas and drought due to heat in others. Moreover, the typhoons and monsoons that routinely visit Bangladesh are intensifying because in the course and tenure of climate change.
Scientists project that concentrations of greenhouse gases will be high enough by 2100 to push temperatures past the threshold level.
A new study from the National Snow and Ice Data Center in Boulder, Colorado in the USA shows that scientists grossly underestimated the rate of ice loss due to warming from greenhouse gas emissions. The study claims that if current trends continue, the world could be facing an ice-free Arctic summer within the next 50 years.
According to the Intergovernmental Panel on Climate Change -- an Environment programmed supported by the U.N, up to one meter of sea level rise is projected by 2100, with half the rise being attributed to melting ice and half to thermal expansion. As and when sea level rises, inundation and loss of coastal land will force millions of people to relocate themselves.
Over the past five years, studies have found that melting Antarctic ice caps contribute to, at least 15 per cent of the current global sea level rise of 2.0mm (0.08in) a year.
The magnitude of possible climate change in the future will depend to a large degree, on the response of ocean circulation to global warming, as the ocean currents distribute an immense quantity of heat around the planet, besides determining the levels of humidity and energy.
The time has come to move beyond academic debates about whether the earth is warming. It is time for taking action and focussing on practical and constructive dialogue about how to adapt to the change in climate over the next 30 years.
We must also develop emissions controls that will restrain the warming sufficiently to allow for adequate ecological and agricultural resources to meet the needs of future generations.
Climate change is not just someone else's concern but a very real threat to the lives and livelihood of people across the globe.
PERHAPS, all concerned would be very happy, had there been no object like an iceberg. The collision of the iceberg with the Titanic -- the most luxurious vessel of its time -- in the North Atlantic Ocean on April 14, 1912 caused deaths of over 1500 people.
It is a matter of concern to think about the future of the world's coastlines in the event of the melting of the West Antarctic Ice Sheet that is projected to raise the global sea levels by as much as 20 feet. Then, the people will not have sufficient land to live.
Commemorating the World Environment Day, as we did on June 5, 2007 with the slogan "Melting Ice-a Hot Topic?" will serve no useful purpose if we do not take any step against the effects of climate change on polar ecosystems and communities and the severe adverse consequences thereof around the world.
There are a plenty of small steps that people can take to save the environment. While the eco-footprint of each step is small, thousands of people doing the same thing can make a difference.
About 20,000 years ago at the height of the Ice Age, sea levels were 400 feet lower than today and there was a lot more land to go around.
If the East Antarctic Ice Sheet melts -- and this monstrous dome will disintegrate anytime sooner or later -- it would raise the sea level around the world by as much as 200 feet.
Ice is melting everywhere -- and it is taking place at an accelerating rate. Rising global temperatures is lengthening melting seasons, thawing frozen ground, and thinning ice caps and glaciers that in some cases have existed for millennia. These changes are raising sea level faster than earlier projected by scientists, and threatening both human and wildlife populations.
The warmer water melts more sea ice, and eventually the warmer atmosphere, above the warmer water, will melt more of the ice sheets on Greenland.
Warming temperatures and more open water will pave the way for greater snowfall, making it more difficult for hunting krill, affecting nesting success. These changes are now very common to be seen in Adelie colonies on the Antarctic Peninsula.
It is thought that over 13,000 sq km of sea ice in the Antarctic Peninsula has been lost over the last 50 years.
During the last 25 years, thousands of Adelies of Humble Island, one of eight islets of Anvers Island where they have nested for some 600 years, have been declining sharply.
The world's second largest ice cap may be melting three times faster than indicated by previous measurements, according to the newly released gravity data collected by satellites.
The Greenland Ice Sheet shrank at a rate of about 239 cubic kilometers per year from April 2002 to November 2005. A team from the University of Texas at Austin in the US, reported it. In course of measurements made during the last 18 months, ice melting has appeared to accelerate, particularly in southeastern Greenland.
Satellite data show Greenland's ice has been melting at higher and higher elevations every year since 1979. A conservative estimate of annual ice loss from Greenland is 50 cubic kilometers (12 cubic miles) per year -- enough water to raise the global sea level by 0.13 millimeters a year.
Based on the observations and deliberations of 300 scientists from eight countries and six groups of indigenous people, the Arctic region, as the Arctic Council reported recently, is warming at twice the rate of the rest of the world and the sea ice that covers the Arctic Ocean is thinning, and could almost disappear in the summer months by 2100.
In addition, their other report from satellite measurements indicates that the area over which ice melts in the summer in Greenland increased 16 per cent between 1979 and 2002 and if the melting continues, sea levels would rise seven meters or so, inundating Florida, New York City, London, and Bangladesh.
Average surface temperatures in the Arctic Circle have risen by more than half a degree Celsius (0.9 degrees Fahrenheit) per decade since 1981. The extent of Arctic sea ice cover has decreased by 7.0-9.0 per cent per decade.
The Arctic melt season has lengthened by 10-17 days, shrinking the amount of ice buildup that remains from year to year and, according to the latest forecasts, the Arctic could be ice-free in the summer by the end of this century.
In 2003, Argentine glaciologists reported that the land-based glaciers, exposed by the removal of those sections, had surged rapidly into the ocean. Thus, although ice shelves are floating and do not add to sea level when they melt or break up, land-based glaciers, released by such events, will definitely add to the sea level.
Ice melting is not limited to the poles. According to glaciologist Lonnie Thompson of Ohio State University, the USA, all but 13 of the 2,000 glaciers in southeast Alaska are retreating. Montana's Glacier National Park may have no glaciers left by 2030, and the ice cap on Tanzania's Kilimanjaro may disappear completely by 2015.
By 2025, Alpine glaciers are likely to contain only half their 1970s' volume, dwindling to 5.0 per cent by the end of the century.
Millions of people living in Asia and South America rely on glacial runoff for drinking water and irrigation. If the glaciers disappear, severe water shortages are sure to follow. Meanwhile, rapidly filling glacial lakes in both the Andes and the Himalayas threaten to break their banks and flood towns below.
Asia's largest rivers, the Ganges and the Bramaputra, converge in the world's most extensive delta and flow into the Bay of Bengal. Every year, thousands of people are displaced by loss of land along these rivers, and the indications are increasing almost every day.
The one meter sea-level rise, as is generally predicted in the event of no action taking place about global warming, will inundate more than 15 per cent of Bangladesh, displacing more than 13 million people. This will adversely affect its rice cropping. Intruding water will damage the Sundarbans mangrove forest, a world heritage site.
Bangladesh's food supply is already threatened by flooding due to melting glaciers in some areas and drought due to heat in others. Moreover, the typhoons and monsoons that routinely visit Bangladesh are intensifying because in the course and tenure of climate change.
Scientists project that concentrations of greenhouse gases will be high enough by 2100 to push temperatures past the threshold level.
A new study from the National Snow and Ice Data Center in Boulder, Colorado in the USA shows that scientists grossly underestimated the rate of ice loss due to warming from greenhouse gas emissions. The study claims that if current trends continue, the world could be facing an ice-free Arctic summer within the next 50 years.
According to the Intergovernmental Panel on Climate Change -- an Environment programmed supported by the U.N, up to one meter of sea level rise is projected by 2100, with half the rise being attributed to melting ice and half to thermal expansion. As and when sea level rises, inundation and loss of coastal land will force millions of people to relocate themselves.
Over the past five years, studies have found that melting Antarctic ice caps contribute to, at least 15 per cent of the current global sea level rise of 2.0mm (0.08in) a year.
The magnitude of possible climate change in the future will depend to a large degree, on the response of ocean circulation to global warming, as the ocean currents distribute an immense quantity of heat around the planet, besides determining the levels of humidity and energy.
The time has come to move beyond academic debates about whether the earth is warming. It is time for taking action and focussing on practical and constructive dialogue about how to adapt to the change in climate over the next 30 years.
We must also develop emissions controls that will restrain the warming sufficiently to allow for adequate ecological and agricultural resources to meet the needs of future generations.
Climate change is not just someone else's concern but a very real threat to the lives and livelihood of people across the globe.