Our planet has two glaciers of continental size, one being present on Antarctica and the other on Greenland. Observations made by scientists over the last thirty-five years all agree upon the notion of shrinking, and or retreating of the ice sheets. The melting of ice sheets has powerful implications for the millions of people who depend on glacial melt for drinking water and the millions of people who will be displaced by the sea level rise occurring as a direct result of the melting. The observations of ice melting also show that the rate at which the ice is melting is accelerating. Mountain glaciers around the world are also on the retreat. Some instances of particular mountain glaciers may show expansion, but studies done by glaciologists show that the total mass of glaciers worldwide is decreasing at an accelerating rate. These studies have been done by a number of different methods that all show a trend in the same direction.
The methods by which polar scientists quantify the amount of ice sheet growth or decline took a large leap in the early 1990s when satellite observations began providing spatially comprehensive sets of data. Three separate methods each with particular approaches and limitations have been used to acquire data on ice sheet mass. Satellite altimetry measures ice sheet volume changes from laser and or radar altimeters. This can be converted to changes in mass by accounting for spatially and temporally varying surface density distribution coupled with spatial exploration of unsampled regions. Limitations of this method, similar to other scientific methods lie in the models used. A second method used is referred to as input-minus-output. Through this method scientists calculate the difference between the sn...
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... Earlier research suggested that the ice sheets might grow under climate change due to the increased precipitation from warmer air holding more moisture. As more recent studies suggest, the actual amount of increased precipitation form global warming is countered by the acceleration of ice-flow into the ocean. In all actually stronger snowfall will just increase future ice discharge. Ice-physics simulations have shown that future discharge of ice into the ocean is increased three times due to the additional precipitation. The snow that is piling up due to the increased moisture in the air is exerting pressure on the ice and increasing the rate at which it flows into the ocean. To clarify the notion; more interior snow does not lead to a lack of sea level rise. This has been quantified using several methods that each focused on the grounded portions of the glaciers.
University of Colorado, Boulder, August 11, 2003, NASA funds Colorado University at Boulder study of changes in Earth’s glacier systems in Ascribe Science News Service: pNa, p 1.
In the essay, “Global Warming is Eroding Glacial Ice,” Andrew C. Revkin argues that global warming is the primary cause for many of the world’s natural disasters; including flash floods, climate change, and the melting of the polar ice caps. He includes multiple accounts of expert testimony as well as a multitude amount of facts and statistics to support his theory that global warming is a threat to the world. However, in the essay “Cold Comfort for ‘Global Warming’,” Phillip Stott makes the complete opposite argument. He argues that global warming is nothing to be worried about and the melting of the polar icecaps is caused by the interglacial period we are currently in. After reading both of these essays and doing extensive research on both viewpoints, I completely agree with Revkin that global warming is an enormous threat to our world today. My research not only helped me to take a stand but it also showed me the invalidity in Stott’s essay.
It is an unquestioned fact that the climate is changing. There is abundant evidence that the world is becoming warmer and warmer. The temperature of the global land average temperature has increased by about 8.5 degrees centigrade from 1880 to 2012 (Karr, et al 406). The one or two degrees increase in temperature can cause dramatic and serious consequences to the earth as well as humans. More extreme weather occurs, such as heat waves and droughts. The Arctic Region is especially sensitive to global climate change. According to the data in recent decades, the temperature in the Arctic has increased by more than 2 degrees centigrade in the recent half century (Przybylak 316). Climate change has led to a series of environmental and ecological negative
It is predicted that the effect of permafrost melting will be that the ocean levels will rise and will significantly increase the temperature and accelerate the rate at which global warming occurs. Permafrost covers 24% of the land in the Northern Hemisphere (Insert Citation), if this was to melt 1700 gigatonnes of methane and carbon dioxide (Insert Citation), powerful heat trapping gases, would be released into the atmosphere increasing the amount of greenhouse gases by 200%.
Glaciers have drastically changed over time because on average, “glaciers worldwide have been losing mass since at least the 1970s”. The melting of glaciers has been contributing to the rise in sea level because the glaciers have been shrinking faster in the last decade. Three of the major glaciers in the us have shown an overall drop in mass since the 1950s and 1960s and an accelerated rate of decline in recent years. An ice cap covered Mt. Hood during the Ice Age, from about 1.8 million years ago to about 10,000 years ago. These ice caps covered the Oregon Cascades, a series of mountains in Oregon, with glaciers going down on the east and west sides of the range. These glaciers melted into smaller glaciers as the weather proceeded to get warmer...
Glaciers flow through three different mechanisms: (1) by internal deformation; (2) by basal sliding; and (3) by subglacial deformation.
People are responsible for higher carbon dioxide atmosphere emissions, while the Earth is now into the Little Ice Age, or just behind it. These factors together cause many years discussions of the main sources of climate changes and the temperature increasing as a result of human been or natural changes and its consequences; even if its lead to the global warming, or to the Earth’s cooling. In their articles, “Global Warming Is Eroding Glacial Ice” by Andrew C. Revkin and “Global Warming Is Not a Threat to Polar Ice” by Philip Stott, both authors discuss these two theories (Revkin 340; Stott 344). Revkin is right that global warming is taking place. Significant increase of carbon dioxide in the atmosphere is due to human activities combined with natural factors such as volcanic emissions and solar radiation – all together they lead to climate changes and temperatures rising. At the same time, other factors such as deforestation contribute to environmental changes for some glaciers not less than air pollution. However, during global warming not all regions of the planet are affected in the same way, local warming and cooling are both possible during these changes.
The glaciers have been through a minimum of four glacial periods. They’ve been through the Little Ice age, which commenced around 4,000 years ago. Marks of retreating glacier ice are seen in the rock-strewn and sculpted peaks valleys. The land and bodies of water that the retreating ice has created a new display of animal and plant communities.
The Little Ice Age was a period of time in which parts of Europe and North America were exposed to colder winters than those generations before and after. This phase lasted a surprisingly long time from around the 1300’s to about 1870. Although it is not considered to be a full on “ice age”, it is said to have many effects on history including important roles on defining how we currently live today.
The term snow is usually restricted to material that fall during precipitation in the form of small white ice crystals formed directly from the water vapour of the air at a temperature of less than 0°C and has not changed much since it fell. A fall of snow on a glacier surface is the first step in the formation of glacier ice, a process that is often long and complex (Cuffey and Paterson, 2010). The transformation of snow to ice occurs in the top layers of the glaciers and the time of the transformation depends mostly on the temperature. Snow develops into ice much more rapidly on Temperate glaciers, where periods of melting alternate with periods when wet snow refreezes, than in Polar glaciers, where the temperature remains well below the freezing point throughout the year. The density of new snow as it falls on glacier surface depends mostly on the weather conditions. In clam conditions, the density of new snow is ρs ≈ 50 – 70 kg m-3 (Table 1.1). If it is windy, there is breaking of the corners of snowflakes, and the density is more like ρs ≈ 100 kg m-3. After the snow has fallen on the surface, there are three processes that are all active together and work to transform the snow to ice.
Glacier melting has become very rapid in the European Alps since 1980, and 10 to 20% of the ice in the Alps was gone in less than two years. Half the amount of Europe's Alpine glaciers has vanished since 1850. Within the next hundred years, 50 % of those left, will as
Jacob, T., Wahr, J., Pfeffer, T. W., & Swenson, S. (2012). Recent contributions of glaciers and ice caps to sea level rise. Nature, 514-518. http://dx.doi.org/10.1038/nature10847
There are many different glacial landforms created by glacial erosion, one of these landforms is U-shaped valleys or glacial troughs. This glacial landform has many distinct characteristics. One of these characteristics is that it has very steep valley sides caused by the glacier as it moves down the valley eroding the sides of the valley by the processes of abrasion and plucking. Abrasion is when the boulders and moraine carried by the glacier rubs and erodes the valley side as it physically moves down the valley. Plucking happens when the water in the glacier freezes inside of the cracks in the individual rocks on the valley side then the water freezes and as the glacier moves the rock is plucked or torn from the valley side producing the steep side to the valley.
Glaciers have disappeared due to increasing in global temperatures because of which the water level had drastically increased and its causing flood all over the world
Global warming is a serious problem with two major effects: increasing sea level and degradation of wildlife. Increase in sea level affects the entire landmass of the earth. According to NASA, the polar ice cap is melting at the alarming rate of nine percent per decade. Arctic ice thickness has decreased 40 percent since the 1960s (Oskin). The amount of water is more than the land on our planet.