GRADE 8 Freshwater and Saltwater Systems SECTION 2

GRADE 8 Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World? Part 3 of 3

2 You will learn to: þ Identify and describe snow, glaciers, and polar ice caps. þ Identify evidence of glacial erosion. o Identify factors that affect the size of glaciers and ice caps. o Describe how humans impact glaciers and ice caps. Let’s get started! GRADE 8 Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World?

3 What happens when the temperature rises? What impacts will melting ice have? freshwater sources habitat oceans GRADE 8 Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World?

4 What happens to the water cycle if temperatures are warmer? Warm air holds more moisture than cold air. “Warmer” can mean -5ºC instead of -15ºC. GRADE 8 Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World?

5 What will happen to water supplies in summer? More snow might fall in some places, but not everywhere. It will also melt sooner. Los Angeles, CA GRADE 8 Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World?

6 How do we know how climate has changed over thousands of years? ice core glacial ice layers Clues to climate can be found in tree growth rings, the tiny shells of animals piled up on the ocean floor, and in ice itself. GRADE 8 USGS National Ice Core Laboratory Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World?

7 What was cooler climate like in the past? Tens of thousands of years ago, ice sheets covered much of North America and Europe. During ice ages there was less carbon dioxide in the atmosphere. GRADE 8 Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World?

8 What happens when an ice sheet melts? 20, 000 years ago, so much water was trapped in ice sheets that a land bridge was exposed between Siberia and Alaska. Petermann Glacier, Greenland What impact would rising oceans have around the world today? GRADE 8 Venice, Italy Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World?

9 How do humans affect ice? What could we be doing that is increasing the amount of carbon dioxide in the atmosphere? What could we do to decrease carbon dioxide? GRADE 8 Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World?

10 What are two sources of information that we could use to learn about what Earth’s climate was like thousands or millions of years ago? GRADE 8 Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World?

11 Now you’ve learned to: þ Identify and describe snow, glaciers, and polar ice caps. þ Identify evidence of glacial erosion. þ Identify factors that affect the size of glaciers and ice caps. þ Describe how humans impact glaciers and ice caps. Let’s try an activity! GRADE 8 Freshwater and Saltwater Systems SECTION 2 How Does Frozen Water Shape Our World?