Evidence of Recent Change
Some regions that usually receive snow are receiving less snowfall and do not have as much snow on the ground. Glaciers in the United States and around the world have generally shrunk, and the rate at which they are melting appears to have accelerated over the last decade. Additionally, the amount of ice in the Arctic Ocean has decreased, and many lakes are freezing later in the fall and melting earlier in the spring. Although the natural variability of this complex system is large, the direction of change is clear and the rate of change has taken scientists by surprise. Environmental Protection Agency
After completing this investigation, you should be able to:
- describe evidence of recent changes observed in glacial ice;
- measure changes in glacial area and extent using ImageJ;
- describe recent trends in sea ice extent and volume;
- explain how the ice-albedo feedback loop works; and
- explain the difference between reinforcing and balancing feedback mechanisms.
Keeping track of What You LearnIn these pages, you'll find three kinds of questions.
- Checking In questions are intended to keep you focused on key concepts. They allow you to check if the material is making sense. These questions are often accompanied by hints or answers to let you know if you are on the right track.
- Stop and Think questions are intended to help your teacher assess your understanding of the key concepts and skills. These questions require you to pull some concepts together or apply your knowledge in a new situation.
- Discuss questions are intended to get you talking with your neighbor. These questions require you to pull some concepts together or apply your knowledge in a new situation.