Steven Ircha                                                                                                                       5/29/2013

Earth Science C Even                                                                                                      Ms. Davies

Rowley, D. B. "Earth's Mantle Affects Long-Term Sea-Level Rise Estimates." ScienceDaily. ScienceDaily, 23 May 2013. Web. 29 May 2013.

In recent years, scientists have been learning more and more about sea levels rising and what that means for the climate. However, as it turns out, this sea level rise may not be attributed solely to a raise in carbon dioxide levels or temperature, but may also correlate to plate tectonics. In fact, there once existed a shoreline from Virginia to Florida in prehistoric times that was roughly 280 feet above the current sea level. This shoreline was carved out by waves more than 3 million years ago, triggered by ice-sheet melting. But a team of researches lead by Robert Moucha, Assistant Professor of Earth Sciences at The College of Arts and Sciences, has pointed to evidence that more than current shoreline has been uplifted by more than 210 feet. This is astonishing and means that significantly less ice has melted than we once expected. There is evidence of plate tectonics here.  As the continental plate has moved, it has overridden another plate and risen. The author also points out that the shore is distorted showing the pushing motion of the earth’s mantle. Using this data, we can predict the future sea-level rise and figure out sea-level changes before they happen. Two to three millions years ago, the temperature was only two or three degrees celsius higher, with similar levels of carbon dioxide. Using these estimates, we can accurately determine the amount of ice melted over the last 3 million years and make accurate predictions of future ice mass and melt. Moucha points out the importance of the mantle on sea-level. Through a process of dynamic topography, the process that created the jagged shorelines that exist today, the sea-level has been greatly altered, and the Earth’s landscape drastically changed. Overall, Moucha’s discoveries have been important in better understanding sea-level changes over the past few million years and determining the role of plate tectonics on land mass and oceanic behaviors.

This article is extremely relevant in today’s world. In the past few years, there has been so much talk and debate about global warming. But now, with new evidence like this about levels of carbon dioxide levels being similar, and temperatures actually dropping in the past 3 million years, the equation is complicated again. With new insights into plate tectonics, we now know the importance of looking at all factors of a problem before jumping to a conclusion. The new data, especially about predicting sea-level and shoreline change, will be more and more valuable in our ever more densely populated world. We will have new knowledge in combatting flooding and will be able to chart out the future of Earth’s geography better than ever before. I chose this article because it offers a different perspective of the classic global warming article. This scientist gives perspective of the global climate on a much larger scale. He does not only compare trends of the past few hundred years, but the last few million. He justifies the slight temperature difference and carbon dioxide levels in a very easily understandable way and addresses justify some of the sea-level change with tectonic activity. Overall, it is a very well written article and offers a unique perspective on the issue.

Altogether, this was a very well written and fascinating article. The author thoroughly covered the main aspects of global warming, and justified them using historical evidence of the world’s geography and recent scientific findings. The author’s logic made sense, and overall there were a many good points made. However, there were some questions left. Firstly, the author did not address the substantial ice-melt over the past million years. If the temperature lowered and there was no significant change in Carbon Dioxide levels, then how could there have been such a significant amount of melted ice? Also, how has the Earth’s sea-level changed in the past few hundred years, was there a significant amount of sea-level rise? The article did a good job addressing how the Earth has been subject to great change over long periods of time, but seemed to skip over the recent changes brought on by humans. If the author had addressed all part of this issue, the argument would have been much more adamant, but due to the lack of a few important points, there was simply too great an amount of information left out to make this a truly comprehensive article. Aside from a few missing details, however, the author presents a unique perspective and analyzes a force that is overlooked far too often in approaching this subject.