Climate and the Cryosphere: Unit Overview
Why study the cryosphere?
Snow and ice are everywhere.Many different kinds of snow and ice, including sea ice, lake and river ice, snow cover, glaciers, ice caps and sheets, and frozen ground, make up the cryosphere (a word derived from kryos, the Greek word for cold)the places on Earth where water exists in solid form. Although most of Earth's frozen water is found near the poles, snow and ice can actually be found on all seven continents.
Snow and ice affect lives all over the world.
In many parts of the world, including much of the United States, the cryosphere is a seasonal visitor. For some, snow and ice are a source of recreational activities like skiing, sledding, ice skating, or building a snowman. For others, the cryosphere is a lifeline. With nearly 70% of Earth's fresh water stored in glaciers and ice caps, more than a billion people around the world (Qiu, 2010) rely on the cryosphere as a source of drinking water. In Arctic regions, sea ice provides a home for animals like seals and polar bears, feeding and breeding areas for a variety of migrating species, and hunting grounds for local communities.
Snow and ice are an important part of the global climate system.Acting like a highly reflective blanket, the cryosphere protects Earth from getting too warm. Snow and ice reflect more sunlight than open water or bare ground. The presence or absence of snow and ice affects heating and cooling over the Earth's surface, influencing the entire planet's energy balance. Changes in snow and ice cover affect air temperatures, sea levels, ocean currents, and storm patterns all over the world.
Just as changes in the cryosphere can influence climate, changes in climate can also dramatically alter the Earth's snow- and ice-covered areas. Unlike other substances found on the Earth, snow and ice exist relatively close to their melting points and can easily change back and forth between solid and liquid. With just slight variations in Earth's temperature, thousands of square miles of snow and ice can accumulate or melt, making the cryosphere one of the most powerful indicators of climate and climate change.
The cryosphere provides vital information about past, present, and future climate.Ice cores drilled from ice sheets and glaciers provide annual records of temperature, precipitation, atmospheric composition, volcanic activity, and wind patterns going back more than 800,000 years. Today, scientists also use satellites to observe the cryosphere and monitor changes. Using these data, they are able to make predictions about what the cryosphere and Earth's climate might look like many years from now.
What will I learn?This unit will introduce you to many of the complex issues surrounding the cryosphere and its connections to climate. You will read articles, conduct hands-on lab activities, watch videos, analyze data, maps and graphs, explore online interactives, and discuss ideas with your teacher and classmatesall of which will help you to understand how snow and ice interact with water, air, land, and life to regulate and reflect Earth's climate conditions.
Key QuestionsKey Questions addressed by this unit include:
- What is the cryosphere?
- How and why does the cryosphere change over time and space?
- What are the timescales associated with changes in the cryosphere?
- How do climate and the cryosphere influence each other?