A. Is there any evidence that global warming is responsible for melting the world's glaciers? For this discussion:1. Find 2 scientific articles (with opposing viewpoints) which address the above q
Evidence that global warming is responsible for melting the world’s glaciers
Article 1: Early Warning Signs of Global Warming: Glaciers Melting
Logically, earth get warm up, and scientists says that the warming of the earth is caused by increasing amounts of carbon dioxide which results in higher average temperature globally, though some parts of the world cool down because of the changing of weather patterns in such regions. Authors in this article state that the warming atmosphere causes things in the atmosphere to be warmed. Glaciers being one of the things in the atmosphere are exposed to the air, the airs they are being exposed to are warmer, and that’s why the glaciers melt. This is enough evidence to show that global warming is responsible for melting the world glaciers.
According to this article “Early Warning Signs of Global Warming: Glaciers Melting”, There are glaciers in each continent except in Australia and virtually at all latitudes from the tropics to the poles. The ones that are particularly sensitive indicators of climate change are those mountain glaciers that are found at higher elevations in the mid-latitudes and tropics. To determine the volume of ice in a glacier and its corresponding surface area, thickness, and length consider the balance between inputs (accumulation of snow and ice) and outputs (melting and calving), (Dyurgerov, M. B., and M. Meier. 1997).
The article states that, the balance between inputs and outputs probably changes with change in climate, thus causing change in thickness and the advance or retreat of the glacier. The highest percentage of glaciers melts due to increase in temperature but also sensitive to other climatic factors such as, precipitation, humidity, wind speed, slope and reflectivity of the glacier surface which all affect the balance between inputs and outputs (Fitzharris, 1996).
Article 2: Glacial melting is not caused by global warming
This article opposes the first article’s view that glacial melting is caused by global warming. It establishes the fact that even the extreme green lobby does not dispute: total global warming over the last century has been less than 1 oC. For instance, if the temperature of the air around a glacier is -5 0C or -10 0C, then a rise in temperature to 1 oC will result to a temperature of up to -4 oC or -9 oC, this is too low for melting of glaciers to take place.
According to the article, the assumption that when air warms a little it will lead to glaciers melting is totally wrong. An Indian researcher concluded: “These results suggest that climatic changes in the world started during the early to the mideighteenth century.” This is actually before the historical increase in the air’s carbon dioxide (CO2) content could have been involved in the process of their retreat. That is the reason why such scientists are opposing the view that global warming has to do with glacial melting.
So here is what happens according to this article, “When summer comes around, in glacial areas, glaciers retreat –they have always retreated. The primary mechanism seems to be the sun. The intense sunlight falling on the surface of the ice melts a fine surface layer. This water then runs down fissures, and eventually goes to the bottom of the glacier. There, the water lubricates the interface between the ice and the rock floor. The ice then slides more easily. Sunlight has a major impact and air temperature essentially nothing.” This article even goes further to state that whenever one sees huge blocks of glaciers fracture off and falls into the ocean, is not the ice melting but it is under the influence of gravity since it has been pushed out with diminishing structural support so that large blocks break off. In conclusion, melting of glaciers is not caused by emission of CO2 which is a gas responsible for global warming and thus it has to be something else, most probably sunlight (the more sunlight that falls on a glacier, the more it will move due to water lubrication).
2. Which position do you agree with and why?
This is abit tricky in deciding on which is true after going through the second article with opposing viewpoint. However, it’s logical that there is warming of earth, relating the melting of ice and the breaking of huge blocks of ice is not correct point and also there are areas that don’t receive sunlight but still melting of glaciers takes place, so to my opinion, even though there are other factors responsible for the melting of glaciers, global warming is the most responsible factor.
3. If significant melting is occuring, what might be the global implications?
Scientists have determined that if the significant glacial melting occurs, the Atlantic Meridional Overturning Circulation could be disrupted, it is an important component of global ocean circulation which could result in a global effect. It is stated further that, this could impact the future climate in places such as portions of Europe and North America.
4. Please provide Google Earth views of the glaciers you have chosen to investigate.
Many views are supporting the point that global warming is responsible for melting of glaciers. However there are other views opposing the point of global warming being responsible, for instance, Chaujer states that, “CO2 is not leading to melting glaciers – it has to be something else. I imagine it is sunlight. The more sunlight that falls on a glacier, the more it will move, owing to water lubrication. So, glacier movement is much more likely to be linked to the amount of cloud cover over a period than to any global warming.”
