FINAL PROJECT: Abstract and Reader's Reponse > Global Climate Change and Its Effect on Ice Sheet Dynamics and Sea Level (Abstract and Difficult Reader)
C -- this is a reasonable profile for this setting, with one exception: not likely to find a climate change denier/skeptic in an earth sciences graduate school. Still, nice discussion. :)
You are handling this complexity quite well in your response. I am not sure you need to include this in your project. Ask me about this.
You are handling this complexity quite well in your response. I am not sure you need to include this in your project. Ask me about this.
May 7, 2015 |
Marybeth Shea
Marybeth Shea
Global climate change is causing an increase in mass loss rate on the Greenland ice sheet. With warmer temperatures, ice sheet dynamics are changing, and complicating our understanding of glacial and ice sheet hydrology. Subglacial lakes and saturated crevasses form in topographical lows. Recent studies show that surface meltwater from saturated crevasse fields, englacial and sub glacial lakes can penetrate the ice sheet column and reach the bedrock. Meltwater reaching the bedrock accelerates ice flow, and is a factor in accelerated mass loss. An increase in mass loss coincides with an increase in sea level. Greenland shares similar properties with Antarctica. Velicogna found that mass loss between the two ice sheets are accelerating at a rate of 56 ± 17 GT/yr2 (2006-2009). This acceleration corresponds to .17 ±.05 mm/yr2 sea level rise increase. Additionally, Zwally et al., found that from 2003-2007 the net loss of mass was 171 ± 4 Gta-1 for Greenland. When compared to the results from 1992-2002, which had a net loss of 7 ± 3 Gta-1, the evidence is clear that climate change is drastically affecting the Greenland ice sheet.
Readers Profiles:
Global climate change skeptic, believes that humans cannot impact a huge planet like earth.
Reader’s Response:
Humans are much too small to impact the planet. We all know that the planet changes over time, for instance ice ages. Also for the past 10-15 years global warming has stopped. Even if the ice sheets are melting, millimeters of sea level rise is nothing to worry about. Lastly how do we know the sun is not to blame for this mess?
My Response:
The Earth does cyclically change climates over long periods of times. However an accelerated and steep increase that has been experienced over the past 20 years is much quicker that any time period in our record. Carbon dioxide is a greenhouse gas, and commonly emitted by everyone during daily activity. Carbon dioxide has properties which allow for absorption of heat, which warms the troposphere. Water vapor is also a greenhouse gas, and increasing temperatures lead to an increase in evaporation, which can cause a 'positive feedback.' Additionally the global warming hiatus can be misleading. This term does not suggest that the planet is not still warming, instead the term suggests that Earth is warming less quickly. The reason for this hiatus is now believed to be caused by the Pacific and Atlantic multidecadal oscillations. The slowdown in warming is expected to end in the next few decades.