Glaciers and icecaps are located throughout the world and are used by scientists as a kind of thermometer for the Earth's climate. As some of the planet's oldest and largest glaciers are shrinking, scientists are becoming increasingly worried about how climate change will impact humans. Glaciologists use a variety of scientific methods to measure how glaciers record a climate that has been changing over thousands of years.
Studying Glaciers
Glaciers are located on all of the continents of the world except for Australia. The majority of glaciers, about 90 percent, are located in Antarctica. Another eight percent are located in Greenland. The remaining small percentage of glaciers are scattered throughout North America, South America, Europe, Asia, Africa, New Zealand and Irian Jaya. There are also various types of glaciers in these locations and glaciologists have categorized nine types:
- continental ice sheets
- ice caps
- ice fields
- outlet or piedmont glaciers
- valley glaciers
- mountain glaciers
- glacierets
- ice shelves
- rock glaciers
Some of these glaciers are hundreds of thousands of years old and can be studied for how they have recorded change in the Earth's climate. Through these studies, glaciologists have determined that there have been several ice ages on the planet.
How Do Glaciers Record Climate Change?
Glaciers record climate patterns in a variety of ways and this information is easily accessible to scientists. A core of ice is drilled out of a glacier and taken back to a lab where air bubbles trapped in the ice can be analyzed. These air bubbles represent a snapshot in time and reveal past atmospheric composition, temperature variations and types of vegetation that existed on Earth. Not only do these ice cores provide this kind of climate data, but it is also continuous data, allowing scientists to look at climate variations over thousands of years with no gap, providing a very complete record.
One of the conclusions that scientists have drawn from studying these data is that Earth is currently undergoing a period of climate change. In general, the concentration of carbon dioxide in the Earth's atmosphere is increasing, leading to an increase in atmospheric temperatures. Moreover, the retreating of glaciers worldwide is further proof that global temperatures are increasing.
Glaciers and Sea Level
One of the most devastating hazards associated with the melting of glaciers is sea-level rise. As glaciers melt, the resulting melt water empties out into the oceans and seas. Scientists have estimated that if the entire current volume of ice were to melt because of global warming, the result would be a sea-level rise of about 80 meters (263 feet). A rise in sea-level of this magnitude would displace millions of people currently living in coastal areas.
Sources:
Glacier and Landscape Change in Response to Climate Change - USGS
National Snow and Ice Data Center
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Alexandra Matiella Novak - With a PhD in Geology and expertise in science education, Alexandra is passionate about increasing the public's Earth science literacy.
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