ALASKA'S MELTING GLACIERS
Most people know about the impressive glaciers of Alaska, even if they've never been there. Glaciers are enormous masses of ice formed by the accumulation of snow on mountains over thousands of years. However, visitors expecting to see the wonders of glaciers may find only bare mountainsides in some places because all the ice has melted and the water has flowed into the oceans. Unfortunately, climate change is causing these spectacular glaciers to melt and gradually disappear. This is more than a loss of beauty: the glaciers of the world have kept the Earth cool and the sea level constant for thousands of years.(lines 1–7)
Scientists are trying to find out how fast the glaciers in Alaska are melting and how much water is flowing from them into the oceans. One recent study has discovered that climate change has caused the glaciers to melt much faster than had been previously predicted. The result is that enormous amounts of water are flowing into the oceans. Another study, using photographs taken from satellites, predicts that these glaciers will shrink to about half their current size over the next few years, a much more rapid decrease than expected.(lines 8–13)
It is not only the glaciers in Alaska that are disappearing: glaciers are melting all over the world. Researchers believe that in the decades ahead the increasingly rapid melting of the world's glaciers will cause the sea level to rise by about 25 centimeters. This rise is one of the most serious results of climate change and it will have an enormous impact on society. Large areas of farmland will disappear under the rising oceans, causing food shortages. Also, the flooding of large coastal population centers around the globe, like New York City and Bangkok, may result in the migration of millions of people. The consequences of these developments may be widespread starvation and disease. Some scientists believe that Alaska in particular may play a critical role in the rise of the sea level worldwide. This is because many of Alaska's glaciers are near the ocean, where they melt even more quickly.(lines 14–23)
Volunteers at the Mendenhall Glacier Visitor Center in Juneau, Alaska, use displays, lectures and videos to teach about the dangerous effects of climate change. "People are shocked when they see a video showing one glacier getting smaller and smaller over time," says John Shane, a volunteer at the Visitor Center. "They also learn that the glaciers are disappearing so quickly mainly because of human-caused climate change. I hope everyone realizes that the future of our planet mostly depends on our actions today."(lines 24–29)