Getting to Know the Cryosphere
Part C: The Changing Cryosphere
Tour of the Cryosphere
The Earth is constantly changing all around us. Some changes, like a shift in the direction of a breeze, may be subtle. Other changes, like the landfall of a hurricane, are far more dramatic. Sometimes, subtle changes that occur over an extended period of time can suddenly become dramatic events, like when years of increasing temperatures and ice-melt result in the collapse of an entire ice shelf. Changes in Earth's systems, including changes in the cryosphere, could potentially have profound consequences for life as we know it. (Read Earth System: The Basics (Microsoft Word 2007 (.docx) 151kB Jun6 12) for more information about Earth's systems.)
The cryosphere, particularly in the polar regions, is extremely sensitive to changes in global climate. Therefore, understanding how and why the cryosphere changes over time in response to both natural and human influences is vital for predicting future conditions on our home planet. Scientists use snow and ice as climate "indicators" by monitoring trends in the cryosphere over time. Examples of such indicators include how many square kilometers of the ocean are covered by Arctic sea ice, the balance between snow accumulation and melting in glaciers, and the amount of land covered by snow.
The cryosphere is also very sensitive to feedbackfeedback: exchange between the input and output of a system. loops. In the climate system, a feedback loop is a pattern of interacting processes where a change in one part of the system, through interaction with other parts of the system, either reinforces the original process (positive feedback) or suppresses/weakens the process (negative feedback). In order to model and predict climate variability correctly, feedback loops must be understood. As you make your way through this unit, you'll learn more about many of the different cause and effect scenarios, including feedback loops, that are playing out in the Earth's cryosphere.
Now, let's watch the NASA video, A Tour of the Cryosphere 2009 (below), to learn more about how the cryosphere changes on a variety of timescales, and how the cryosphere affects the lives of everyone on Earth.
For many of you, this unit is your first introduction to the cryosphere. As you watch the video:
Take notes about things that are new, interesting, or confusing to you.
Keep an eye on the date stamp in the upper right corner of the window to get a feel for the timescales over which changes occur in the cryosphere.
NOTE: The video includes audio narration, so make sure you have the volume on your computer switched on.
With a partner, in a small group, or as a whole class, discuss the following question:
- What were the key ideas presented in the Tour of the Cryosphere video?
Everything is connected
Changes in snow and ice conditions in the Arctic can affect people all over the world. A recent study showed that there is a link between the amount of sea ice in the Arctic, particularly during summer months, and altered winter weather patterns at much lower latitudes. The southwestern United States, a region that frequently deals with water shortages, has experienced increased drought during winters following summers of relatively low sea ice extent in the Arctic. Scandinavia, which relies on hydropowerhydropower: power derived from the force or energy of moving water. for the majority of their electricity production, has also experienced decreased precipitation in the wake of diminished Arctic sea ice.
Life and the Cryosphere
Depending on where it is you call home, it may not be immediately obvious what role the cryosphere plays in your life, but the condition of the cryosphere impacts the whole worldeven in warm and temperate regions where snow and ice are either rare or nonexistent. Snow and ice help regulate global climate, drive ocean currents, and provide fresh drinking water for much of the world.
For centuries, people in the Arctic have relied on the predictability of snow and ice for their survival. However, recent changes in climate have caused snow, ice, and weather patterns in high latitude native communities to become uggianaqtuq (pronounced OOG-gi-a-nak-took)a North Baffin Inuktitut word that means to behave unexpectedly, or in an unfamiliar way. Changes to the cryosphere in and around these communities impact a myriad of things including hunting, coastal erosion, ocean productivity, transportation, and animal habitats.
Watch this 5 minute long Eyewitness Documentary of Climate Change in the Arctic to learn about how unexpected changes in the cryosphere are affecting Arctic people's way of life.
Stop and Think1: In your own words, summarize the cryosphere. What is it? What is it made of? Where can you find it?
2: Why do you think it is important for scientists to monitor changes in the cryosphere? Explain.
Even if you don't live in the Arctic, significant changes to the cryosphere could have a major impact on your life. As a class, discuss the following questions:
- How is your life currently affected or influenced by the cryosphere?
- What consequences do you think you might experience if the cryosphere were suddenly or drastically altered? What evidence could you use to support your hypotheses?