Prior Knowledge and Ideas:
The scenario this week is on ice sheets and the ramifications caused by an
increase in ice melt. I already know from the media and watching Al Gore’s movie
“Inconvenient Truth” that the ice sheets have been receding for the past few decades. I
have seen numerous pictures of glaciers before they melted and years later, when they
began to melt. They are pretty significant. I know that most people believe that the
cause of ice melt is global warming, which makes since. However, an agreement on what
causes global warming has not been agreed upon in society. Some individuals feel that
global warming is caused by human activity, while others feel it is a natural cycle. This
is one thing that must be decided on in order to learn how to mitigate of lessen the impact
of ice melt.
If the ice sheets melt serious ramifications will occur. Not only will sea level rise,
but this increase in fresh water in our oceans will dampen, or end, thermohaline
circulation. Not to mention once the ice sheets start to melt and disappear it may start a
cycle that becomes irreversible. This is because as the ice sheets melt we loose a high
reflective surface and gain a surface (open water) that readily absorbs the sun's radiation.
This in turn heats the atmosphere, causing great climate changes, and increasing the cycle
of global warming.
Global warming can cause such a dramatic change in the circulation patterns of the
ocean because it would disrupt the driving force behind that circulation, the temperatures
and saline content of the water. As air temperatures around the global increase, surface
temperatures of the water would also increase. This would decrease the density of the
water masses slowing their movement. Also, a further increase in temperatures may
create more surface water run-off, and the melting of the polar ice caps. This added fresh
water to the ocean will decrease the salinity content, further diluting the ocean and
weakening the driving force behind the global conveyor belt, possibility shutting it down
completely (Kloeppel, 2005).
Global thermohaline circulation plays a major role in the climate of the Earth and
the distribution of nutrients within our Ocean. If the North Atlantic Deep Water mass
disappears because of global warming, Europe will face much harsher winters due to the
fact that the thermohaline circulation will stop bringing them warm temperatures. All the
important water types, including deep water, shallow water, and intermediate water, play
an important role in the circulation pattern of the global conveyor belt, which brings cold
water from the Polar Regions to the mid-latitudes and then flows back to the Polar
Regions to start the cycle again. To keep this global conveyor belt moving preventive
steps must be taken in order to stop global warming.
References
Kloeppel, J (2005). Global warming could halt ocean circulation, with harmful results. News
Bureau, University of Illinois at Urbana-Champaign