Melting Glaciers Are Evidence of Global Warming

Global climate change is one of the most hotly contested issues in the world. However, there is sufficient data to suggest that the observed melting of glaciers and ice caps around the world is caused by global warming.
Melting Glaciers and Ice Caps: The Evidence

According to Gary Braasch of World View of Global Warming, hundreds of glaciers worldwide are in retreat. The phenomenon has been occurring throughout the twentieth century and continues today. Mountain glaciers are especially sensitive to temperature changes, and most mountain glaciers around the world are shrinking, with some disappearing altogether, as described by A’ndrea Elyse Messer in the February 2005 NASA Earth Observatory news release “Melting Ice Indicator of Global Warming.”

Individual accounts of the melting are staggering. The National Park Service estimates that all but a few of Glacier National Park’s thirty mountain glaciers will be gone by 2050. In the Alps, the Rhone glacier in Switzerland has receded 2.5 km in 142 years, and the Pasterze glacier in Austria shrinks by 15 m each year. In the Northwestern US, scientists have observed rising snow lines, decreased mountain snowpack, and earlier spring runoffs.

Braasch points out that the loss of tropical glaciers has been particularly rapid. In the Andes, the Broggi glacier near Huascaran, Peru has receded 1 km in the past 67 years. The Ururashraju glacier, also in Peru, receded 500 m between 1986 and 1999, just 13 years.

In the October 5, 2009, CNN.com article “The High Stakes of Melting Himalayan Glaciers,” Reenita Molhotra points out that glaciers in the Himalayas are receding more quickly than glaciers in other parts of the world. Between 1962 and 2004, over 1000 glaciers shrank by at least 16%. The Intergovernmental Panel on Climate Change estimates that all Himalayan glaciers will be gone by 2035.

Mountain glaciers are not the only forms of ice melting. Polar ice caps have also been severely affected. In 2002, the Larsen Ice Shelf in Antarctica lost a 1200-square-mile section. More recently, a 54-square-mile iceberg that originally broke off of the Ross Sea Ice Shelf has been drifting towards Australia.

In the Arctic, satellite data shows that Greenland’s outflow glaciers appear to be thinning and flowing more rapidly. 2000 saw the warmest ocean temperatures at the North Pole in 400 years, according to Steven Marshak in Earth: Portrait of a Planet (W. W. Norton and Company, 2001), and a 15 km by 5 km open patch in the polar ice was discovered. Messer also points out that the Arctic is experiencing a shift in the snowy season and smaller and thinner sea ice.
Is It Really Global Warming?

According to Penn State glaciologist Dr. Richard B. Alley, the melting is a sign of global warming. This is because the melting is observed worldwide in a variety of environments and locales. Dr. Alley has been using satellite data to monitor the movement of glaciers and states that “the ice changes are best explained by warming.”

In the May 2001 NASA Earth Observatory news release “Melting Glaciers Signal Global Warming,” James Hathaway describes Rick Wessels, an Arizona State University geologist who has been using satellite data to track glaciers in a long-term, worldwide study. While Hathaway points out that the cause of global warming may still be up for debate, Wessels feels “there is definitely a global climate change.”
Effects of Global Warming, Melting of Glaciers

What does all this melting mean for the Earth’s future? The predictions are grim. Braasch reports an estimated three foot rise in global sea level by the end of the century if melting continues at its current rate, and Marshak cites studies that show that global sea level could rise by as much as 230 feet if all the polar ice caps melted. This would lead to extensive flooding of coastal plains and cities.

There is also fear that severe environmental changes could lead to civil unrest. As Braasch points out, seasonal melt water from glaciers provides water to scores of people, especially those in Asia and South America. According to Molhotra, runoff from Himalayan glaciers is an important source of freshwater in the region and supplies almost all major rivers in Southeast Asia, including the Indus, the Mekong, and the Yangtze. Glacial runoff accounts for almost 70% of flow in these rivers, with the other 30% coming from seasonal monsoons. If the Himalayan glaciers disappear, the region could face severe water shortages, potentially leading to civil, political, and even religious conflict.

At this time, there are still many questions to be answered about global climate change. Is it natural or a product of human industrialization? Is the planet facing a long-term change, or is this just a brief climate cycle? However, in the face of these questions, the melting of the world’s glaciers are a significant sign that warming is indeed occurring.