Glacial Ice Melting Due to Global Warming

Satellite Monitoring

• Scientists have been measuring the planet's temperature long before global warming became a topical issue. Using thermometers is a logical method of measuring temperature, but according ot NASA, scientists this method produces unreliable results because temperatures vary widely across regions and during seasons, making it impossible to get a true global picture. Instead, they use satellites that measure heat-sensitive objects on the Earth's surface. The satellites provide data that translates into average global temperatures. The satellite data also shows that glaciers are the most reliable indicators of climate change.

Suitable Glaciers

• Not all glaciers are suitable for monitoring, often because they are simply too big, such as the Greenland and Antarctic ice sheets that form 90 percent of the Earth's glaciers. Suitable glaciers are usually small. land-based and respond to regional temperatures and snowfall. When scientists find a suitable glacier, it is monitored by satellite for at least five years, and the images studied for signs of change. The outside edge of the glacier is examined to see if large portions of it are receding. If the edge of the glacier is receding, then the area around the glacier is warming up. If the glacier is getting bigger, then the ground is cooling down.

Glacial Shrinkage

• It takes years to detect glacial change, and some changes can be misleading. For example, a receding glacier edge appears to indicate warming temperatures. However, the center of the glacier may be thickening. Satellites can't pick up this information, which is why scientists also have to manually collect data from the glacier in order to verify the findings. One of the manual monitoring methods involves sticking a stake in the glacier and returning periodically to see if the glacier's height has changed.

Results

• According to Dr. Dorothy Hall, an expert on climate and glaciers, the scientific evidence shows that glaciers are shrinking at a steady pace and that this confirms rising temperatures. However, this increase in temperature may be part of a natural cycle that has possibly been exacerbated by burning fossil fuels. As Dr. Hall points out, scientists still don't know the exact cause of global warming. According to the Water Encyclopedia website, the Himalayan glaciers, which form the largest glacial area apart from the polar ice caps, are disappearing at a faster rate than any other land glaciers. In Glacier Mountain Park in Montana, the number of glaciers declined from 150 in 1850 to 50 in 2000.