User:Sirleroy91

Sirleroy91 I am a 3rd year nursing student attending Thompson Rivers University in Kamloops BC, Canada. User:Sirleroy91/Sandbox

Preliminary post: Climate Change and Glacial Melt

Climate Change and Glacial Melt
A glacier is a mass of ice originating from compacting snow via pressure with definite lateral limits and movements in definite directions. They are found in areas where the temperatures do not get warm enough to melt annual snow accumulation. Global climate change and fluctuation is causing an increasingly exponential melting of Earth’s glaciers. Melting glaciers have many social and ecological consequences that directly or indirectly impact the health and well-being of humans. The recession of glaciers change sea-salt, sediment, and temperature ratios in the ocean which changes currents, weather patterns, and marine life (Epstein). The melt also increases ocean levels and decreases the availability of water for human consumption, agricultural, hydroelectricity, adding to issues from sanitation to hunger to population shifts, and catastrophic weather such as flooding, drought, and temperature fluctuations (Epstein).

“Glacier mass-balances show consistent decreases over the last century in most regions of the world and retreat may be accelerating in many locations (Durgerov & Meier, 2000) with an average loss of ten meters per year, nearly twice as fast as ten years ago (Dan, V, N.D.). Glaciers currently cover ~10% of the Earth’s surface, or ~15 million km² and holds ~75% of Earth’s fresh water supply. Glacial retreat first gained the attention of alpinists and the tourist industry after 1940 – when the globe warmed ~0.5ºC. Even with 62 years of awareness, climate change is just becoming an issue for some parts of society. Over this time period the cirque and steep alpine glaciers were able to acclimatize to the new temperatures posed by climate change; large valley glaciers have not yet made this adjustment. This means the large valley glaciers are rapidly retreating, as their mass is attempting to achieve equilibrium with the current climate. If the snow lines stay constant, then the glaciers remain constant, but this is clearly not the case as global warming is causing mountain snow lines to retreat. Even the United States’ famous Glacier National Park is receding. More than two-thirds of its glaciers have disappeared and it is expected for them to be nonexistent in the park by the year 2030 (Hall & Fagre, 2003).

Glacial melt will affect low lying coastal wetlands via sea level rise, change the key drivers of fresh water ecosystems, shift the timing of snowpacks, and alter the unique character of associated streams off of snowpack (Jenkins, Kingsford, Closs, Wolfenden, Matthaei and Hay, 2011). Jenkins, et al. (2011) state that the sea level will rise 28-43 cm by 2100; if all the ice on Earth melts, the ocean level will increase 75 meters, destroying many coastal cities (Epstein). In addition, the freshwater swaps in the Northern Territory are already affected by the intrusion of salt water. “Sea level rise will cause a change of state from freshwater to marine or estuarine ecosystems, radically altering the composition of biotic communities” (Jenkins, et al. 2011).

Not only are glaciers causing a rise in sea level, they are causing an increase in El Niño Southern Oscillation (ESNO) and global temperature itself. Glacier loss adds to global heat rise through a decrease in what is called ice-albedo feedback. As more ice melts, there is less solar reflectivity and less heat is reflected away from the Earth, causing more heat to be absorbed, and retained in the atmosphere and soil (Epstein). In addition to the El Niño events, glacial melt is contributing to the rapid turnover of sea surface temperatures [2] and ocean salt content by diluting the ocean water and slowing the Atlantic conveyor’s usually swift dive because of a top layer of buoyant layer of cold, fresh water that slows the flow of warm water to the north (Epstein).

Fifty percent of the world’s fresh water consumption is dependent glacial runoff (Myrna & Fagre, 2003). The glaciers are expected to melt within the next forty years, greatly decreasing fresh water flow in the hotter times of the year, causing everyone to depend on rainwater, resulting in large shortages and fluctuations in fresh water availability, largely effecting agriculture and power supply (Epstein). Many power sources and a large portion of agriculture rely on glacier runoff in the late summer. “In many parts of the world, disappearing mountain glaciers and droughts will make fresh, clean water for drinking, bathing, and other necessary human (and livestock) uses scarce and a valuable commodity (Epstein).

Jenkins, K. M., Kingsford, R. T., Closs, G. P., Wolfenden, B. J., Matthaei, C.D., and Hay, S. E. (2011). Climate change and freshwater ecosystems in Oceania: an assessment of vulnerability and adaption opportunities. Pacific Conservation Biology. 17, 201-219.

Penny, L. 2011. Watching the arctic melt, I realise apathy must be frozen out. New Statesman.

Brown, L. E., Hannah, D. M., and Milner, A. M. (2007). Vulnerability of alpine stream biodiversity to shrinking glaciers and snowpacks. Global Change Biology.13, 958-966.

Orlove, B. (2009). Glacier Retreat: Reviewing the Limits of Human Adaptation to Climate Change. Environment, 51(3), 22-34.

-Modeled Climate-Induced Glacier Change in Glacier National Park, 1850-2100. Authors:Hall, Myrna H. P.,Fagre, Daniel B. Source:BioScience Date:2003. Publication Type: Academic Journal

Dan, V. (n.d). Greenland glacier runoff doubled over past decade. USA Today. http://usatoday30.usatoday.com/tech/science/2006-02-16-glacier-melt_x.htm (cite Dan in place of epstein for part where coastal damage is mentioned)