Global Warming Essay

Submitted By samwise11
Words: 1672
Pages: 7

Global warming has fast become the foremost environmental challenge facing the world to date. In the last decade, a lot of debate has arisen about weather Global warming truly exists, and if it really does exist then why. Many people believe it to be a natural phenomenon, but accurate scientific data and testing prove the existence to be a far more worrying dilemma than most understand. In this essay I will be arguing the existence of global warming at the Antarctic ice sheet and the effects of it’s thinning in the 20th and 21st centuries. Firstly, I will integrate the different Earth systems concerning the existence of global warming, followed by suitable evidence and data further contributing toward the existence of the changing climate. Secondly, I will incorporate how the Earth system processes relate specifically to economic, social and political factors and how these factors may directly concern people. From this analysis it can be seen that global warming is melting the Antarctic ice shelf from atmospheric and ocean temperatures increasing.
The significance of earth system processes causing a change in Antarctic ice mass and climate is essential in understanding climate change all over the world as it is the key regulator of global climate (British Antarctic Survey, 2007). Atmospheric and oceanic forces are the central drivers behind the reduction in thickness behind the melting ice sheets. International climate panels have determined that global warming, the average warming of the earth surface, over the last five decades is likely to be due to the increase in greenhouse gas concentrations in the atmosphere and ocean (Vaughn, 2003). The first thing to be aware of is that the effects of the changing climate, on the Antarctic ice sheets, is a seasonal growth in thinning. Observations show summer melt increasing substantially through the 20th century, but also an increase in winter snow particularly at higher elevations. However, the decline continues to outpace the accumulation, on average, because warmer atmospheric temperatures have led to increased melting and faster glacier movement at the island's edges (Vaughn, 2003). At times across the Antarctic adjacent ice shelves, with one coast thinning, the other appears to be accumulating in the last ten years, which is especially strange as areas appear to have similar atmospheric forcing but have contrasting elevation. This allows for the idea that the thinning is caused not only by upper surface climate change and the variation of atmospheric temperature and pressures, but therefor must be primarily due to other regional forces. It is reasoned that the thinning is caused by basal melt driven by ocean interaction at the lower surfaces (Pritchard & Ligtenberg, 2012). “High basal melting is fuelled by an influx of relatively warm ocean waters from the Southern Pacific Ocean” (Rignot, 1998. pp.46). With the increased piling of greenhouse gases into the atmosphere throughout the 20th century the Southern Ocean has warmed significantly and warming is concentrated in the ACC (Antarctic Circumpolar Current). The migration of warmth may be driven by the changes in wind latitude allowing the warmer water to encompass the ACC. Ice shelf thinning by basal melt implies an increased oceanic heat supply into the sub-ice-shelf cavities (Pritchard, Ligtenberg 2012).
Concentrating on two different cases, we can then prove the existence of thinning at the Antarctic Ice Shelf. Using data we can then analyse the average fluctuations of ice mass at the Pine Island Glacier ice shelf. After attempts in both 2007 and 2011, it wasn’t until December 2012 when NASA sent a team to the remote corner of Antarctica to install equipment allowing them to measure the rate of change. At one specific site, halfway down the ice shelf, the melt rate was as high as 72 feet (22 meters) per year (Vinas, 2013). Bindschadler (2013) a glaciologist, said that “direct measurements are consistent with larger