Water, Weather, and Climate

KEY QUESTION: How do water systems, weather, and climate affect each other?

Looking Ahead

• The climate of a region, and the weather on any particular day, are affected by

large bodies of surface water.

• Climate affects water’s temperature and changes of state on Earth.

• Research skills can be used to assess issues related to local and global water

supply.

• Global warming is affecting water systems around the world.

• The long-term sustainability of water systems depends on how well we

manage and care for water.

• The skills of scientific inquiry can be used to compare water use around the

world.

CHAPTER

12

Water, Weather, and Climate — Activity

• Looking at the map below and the four major cities indicated,

predict which cities are coldest to warmest in the winter by

ranking them 1-4.

• Coldest City: 1.

2.

3.

4.

• Give reasons for your choices.

• See next slide for

city temperatures.

CHAPTER

12

Water, Weather, and Climate — Activity

• Did your predictions match the temperatures given? Record

the actual ranking next to your guesses.

• Can you predict a trend with

temperatures and city location?

• Read Chapter 12.1 to learn

more about weather and

climate.

CHAPTER

12

Reading Science and TechnologyAnd Here is a Severe Weather Warning…

CHAPTER

12

Text Genres: The Comic Strip

To understand this comic strip, you need to read in a non-linear manner, scanning both the pictures and text to follow the story. You may also need to make connections between pictures, text, and your background knowledge. Sometimes, a message is hidden and you must make an inference to figure out the meaning. Read the comic strip, then work with a partner to discuss the following:

1. Some of the text is spoken by characters, while some of the text represents what they are hearing. What helps you distinguish between the two?

2. What inference can you make about why the Rideau River area flooded?

3. Describe the characters’ feelings in the last frame. Why are they feeling this way. How do you know?

Surface Water and Climate

• Weather is a set of environmental conditions that changes from day to day.

• Climate, on the other hand, is a set of environmental conditions averaged

over 30 years. It does not describe any particular event at any particular

time.

• Energy from the Sun drives the evaporation of water in the water cycle and

also heats Earth’s surface. At night, Earth cools down and radiates out its

energy.

• The high heat capacity of water means it can store and release more thermal

energy than soil or rock. Water helps keep Earth’s temperature fairly

constant from day to night

• When air becomes warm, it becomes less dense. This difference in density

causes air movements called convection currents.

• Inland cities experience colder winters and hotter summers that cities near

large bodies of water.

weather

climate

heat capacity

heat sink

convection

12.1

Glaciers, Polar Ice, and Global Warming

global warming

• Glaciers, icecaps, and polar ice sheets are sensitive indicators of

changes in climate.

• When the climate is cold for centuries the ice in glaciers builds up.

If there is less precipitation than usual for several years, or if more

ice melts than usual, then the ice cover starts to shrink.

• Climate scientists believe that the shrinking ice is a sign that the

temperature of Earth’s surface is gradually rising – a process

called global warming.

• Global warming is lowering the water levels in the Great Lakes

because it is evaporating faster than it is being replaced with

precipitation.

• Global warming melts glaciers and icecaps,

and warms ocean currents and air currents.

12.2

Water Exports (Explore and Issue Critically)

• A multinational company has had a permit to extract water from a

local water source near Guelph, Ontario, for the past few years, to

sell as bottled spring water. Citizens are worried about drawing

too much water from one aquifer. In 2008, the Ministry of the

Environment rejected the five-year renewal request to extract

water, but granted a two-year renewal.

• Share your letter with another student who has taken a different

position. Discuss the rationale behind your respective choices.

12.3

Floods and Droughts

flood plain

• Floods usually result from heavy rainfall or rapid snowmelt.

• Flash floods are generally produced by a sudden storm that

stalls over one location.

• Ice-jam floods usually occur in the spring along Ontario’s

rivers.

• Homes should not be built on, or too close to, flood plains

(the low area of land alongside a river).

• Droughts are caused by dry weather conditions where water

evaporates faster than it is replenished.

• Water shortages are often caused by human activities, such

as damming rivers, or removing water for irrigation and

bottling.

• Vegetation and trees help prevent water loss during dry

periods.

12.4

Global Access to Safe Drinking Water (Perform an Activity)

• In this activity, you will try to represent the difficulties in obtaining

safe drinking water experienced by people in various countries.

Equipment and Materials

12.5

12.5Global Access to Safe Drinking Water (Perform an Activity)

Safety

Never run in the science classroom

Water is Life

• Over 1 billion people on Earth (one-sixth of the world

population) do not have access to safe drinking water, while

others waste water daily.

• The world’s first “Water Day” was March 22, 2005. This day

marked the start of the “Water for Life” decade, when the UN

announced a ten-year target to achieve:

• To reduce by half the number of people that do not have

access to safe drinking water and basic sanitation by the

year 2015.

• Access to sufficient clean water is a fundamental human

right.

• Access to clean water is crucial to everyone for health, food

production, and

economic development.

• The why do the “water-rich” nations treat water as a product

they can package and sell?

12.6

Water Footprints(Perform an Activity)

• In this activity, you will compare the water footprints of “water-rich”

countries with those of “water-poor” countries.

12.7

Summary – Looking Back

CHAPTER

12• The climate of a region, and the weather on any particular day,

are affected by large bodies of surface water.

• Water has a high heat capacity. It can absorb or release a lot of

thermal energy without changing its temperature significantly.

Water is a heat sink.

• Lakes and oceans act as heat sinks, making the climate milder

in coastal and lakeside areas than in inland areas.

• The difference in temperature between air over water and air

over land causes convection currents in the air (wind).

• Floods occur when there is too much rain and meltwater;

streams and rivers overflow their banks. Droughts

occur when there is not enough rain;

streams, rivers, and lakes dry up.

Summary – Looking Back

• Climate affects water’s temperature and changes of state on Earth.

• Near the North and South poles, precipitation is in the form of snow.

The snow builds up over centuries, forming glaciers, ice sheets, and

icecaps.

• Near the Equator, precipitation is in the form of rain.

• Between the Equator and the poles, precipitation may be in the form

of snow for some of the year, but this snow melts each spring.

• The warmer the climate, the more easily surface water evaporates,

which may lead to droughts.

CHAPTER

12

Summary – Looking Back

• Research skills can be used to assess issues related to local and

global water supply.

• Different media sources can be used to research issues related to

exporting water.

• Media sources present differing opinions on water issues.

• Global warming is affecting water systems around the world.

• Global warming is causing glaciers, ice sheets, and icecaps to melt.

This results in more water flowing into the oceans.

• Global warming is increasing the temperature of Earth’s surface

water.

• Sea levels are rising as the global temperature increase because

warmer water has a greater volume than cooler water.

CHAPTER

12

Summary – Looking Back

• The long-term sustainability of water systems depends on how well

we manage and care for water.

• Water use must be carefully planned and managed to ensure that

there will be enough clean water to meet the needs of people around

the world.

• Human activity affects the flow of water and the quality of water in a

local water system. Withdrawing water for drinking, irrigation, and

export reduces our water supply.

• The skills of scientific inquiry can be used to compare water use

around the world.

• Water footprints can be used to compare water use among

countries.

• Water footprints can also be used to identify areas in which we can

reduce water.

CHAPTER

12

QuizMultiple choice

For each question, select the best answer from the four alternatives.

1. A description of the environmental conditions averaged over many years is called…

a) The weather.

b) The climate.

c) Heat capacity

d) Global warming.

2. Global warming is causing the Great Lakes’ water levels to…

a) Rise.

b) Fall.

c) Stay the same.

d) Go up and down.

3. Access to sufficient clean water is… ?

a) A privilege.

b) A basic human right.

c) A luxury.

d) Not necessary.

CHAPTER

12

Quiz

True/False

Indicate whether each of the statements is TRUE or FALSE. If you

think the statement is false, rewrite it to make it true.

4. The lower the heat capacity of a substance, the more thermal

energy it can store.

5. Heat sinks can absorb a lot of thermal energy without

significantly increasing in temperature.

6. A rise in ocean temperatures can mean smaller, and less

frequent storms.

7. Trees and vegetation naturally resist droughts.

8. Human activities often cause floods.

CHAPTER

12

Quiz

Short answer

Write a short answer to each of these questions.

9. Describe why coastal cities experience milder winters and cooler

summers than inland cities?

10.Explain the following diagram in your own words, referencing

density and temperature relationships.

CHAPTER

12

Quiz AnswersMultiple choice

For each question, select the best answer from the four alternatives.

1. A description of the environmental conditions averaged over many years is called…

a) The weather.

b) The climate.

c) Heat capacity

d) Global warming.

2. Global warming is causing the Great Lakes’ water levels to…

a) Rise.

b) Fall.

c) Stay the same.

d) Go up and down.

3. Access to sufficient clean water is… ?

a) A privilege.

b) A basic human right.

c) A luxury.

d) Not necessary.

CHAPTER

12

Quiz

True/False

Indicate whether each of the statements is TRUE or FALSE. If you

think the statement is false, rewrite it to make it true.

4. FALSE; The higher the heat capacity of a substance, the more

thermal energy it can store.

5. TRUE; Heat sinks can absorb a lot of thermal energy without

significantly increasing in temperature.

6. FALSE; A rise in ocean temperatures can mean larger, and

more frequent storms.

7. TRUE; Trees and vegetation naturally resist droughts.

8. FALSE; Natural disasters cause floods.

CHAPTER

12

Quiz

Short answer

Write a short answer to each of these questions.

9. Describe why coastal cities experience milder winters and cooler

summers than inland cities?

Answers may vary.

Water has a high heat capacity and can both store and release

large amounts of thermal energy without its temperature

changing drastically. In the winter, water can keep coastal

cities warmer by releasing thermal energy, while in the

summer water can absorb thermal energy.

10.Explain the following diagram in your own words, referencing

density and temperature relationships.

Answers may vary.

During the day, the land heats up faster than the water, which

then warms the air above it. The air over the water remains

cool. As the warmer, less dense air rises, the heavier, cooler

air replaces it generating wind called “convection currents.”

CHAPTER

12

Solving a Water Issue(Unit Task)

UNIT

DIn the Unit Task, you will find out about an award that is being offered for a

solution to a problem involving water. You will choose an issue that may be

affecting a water source anywhere in the world. You will be asked to prepare

and test an action plan to address the issue. Or, you may design, build, and test

a prototype of a device that solves a water problem. Whichever option you

choose, you will collect data during trials. You will then use your data in a news

media release that describes the success of your action plan or device