Greenland’s ice is melting, however the speed at which this is occurring is debated. According to National Public Radio, a scientist named Ian Joughin of the University of Washington arrived at a net rate of 30 percent after analyzing ice sheet melt data with his colleagues. Even though this is a substantial rate, it serves to dispel some of the more urgent fears inspired by a news report recently released by the National Aeronautical and Space Administration.
NASA recently released data stating 57 percent of the surface area of Greenland’s ice sheet melted over a period of days due to high temperatures. However, according to the New York Times, this statement had a more dramatic tone than was justifiable with the words “unprecedented Greenland ice sheet melt.” Regardless of how figuratively those words are interpreted, NASA did not in fact misstate what had happened. Rather, NASA chose not to choose alternate wording such as unprecedented one time melt event in Greenland.
The data observed by NASA are attributable to an event that occurs approximately once every 1.5 centuries according to a NASA glaciologist and as reported by National Geographic. More specifically, analysis of core ice samples shows that massive or “unprecedented” melts of the scale that took place between July 8 – 12, 2012 are in a sense, normal. However, how close a scale these previous ice melts were is not specified.
Scientists are faced with the challenge of distinguishing ice melting patterns by their causes. In other words, determining if global warming is what triggered the event observed by NASA involves excluding other phenomenon such as statistical probability of ice melt toward the higher end of a historical ice melt rate range. Such being the case, automatically assuming the disturbing Greenland event is purely a result of global warming is more like speculation.
Climatological data confuses the issue of what caused the ice sheet melt. For example, the National Climatic Data Center June 2012 report indicates record cold temperatures in both the Northern and Southern hemispheres, yet in the United States hundreds of heat records were broken around the same time. What is evident in both climatological data, and NASA’s observations of Greenland’s ice sheet is that extreme climatological events have been taking place recently.
A question that has been debated around global warming is whether or not it causes extreme weather that leads to events such increased rate of glacial melting in Greenland. The Environmental Protection Agency states extreme weather is sometimes natural, and that global warming has occurred naturally in Earth’s history. However, advocates of global warming such as the Environmental Defense Fund are more likely to state the rate at which extreme weather is occurring is beyond a normal range, and that it is caused by humans.