The importance of climate change and heat transfer
Climate change and heat transfer can significantly impact the air we breathe, the surroundings we see, and the future well-being of the planet. Preserving wildlife, recycling to ensure we are environmentally conscious, and promoting healthier lifestyles are a few examples of how climate change and heat transfer impact our lives. In this first learning activity, you will have the opportunity to further develop your transferable skills in communication and citizenship.
Fact: Did you know that meteorology, energy, and media are all industries related to climate change and heat transfer?
Let’s get started to learn more!
Earth's climate system
In this first learning activity, you will learn about the basic components of the Earth’s climate system and the complex ways they are interconnected. What happens in one place has consequences for the entire globe. But why are these components so connected? It’s because of the transfer of heat. Heat transfer causes ocean currents to flow and storms to move across the country. Due to heat transfer flowers start growing in Vancouver in February while Winnipeg is still freezing under several feet of snow – even though both cities are at similar latitudes.
Action Part 1: Climate system and climate change
Action Part 3: Local convection currents
Action Part 1: Climate system and climate change
To understand climate change, you first need to know the difference between weather and climate as well as how climate works. Then you can begin to inquire about how much our climate could change and how to distinguish normal variation from human-caused change.
The study of the climate system is really the study of heat transfer. In this first learning activity, you will learn how heat is moved around the planet from the hot tropics to the cold polar regions.
Climate versus weather
Climate is the pattern of temperature and precipitation for a region averaged over many years. The localized day-to-day variations in climate are called weather.
As you know, predicting weather can be very difficult, but predicting climate is easier because it is controlled by powerful forces over large areas, and so is more consistent. The weather office can’t predict what the weather will be like on a specific day next July, but it can predict it will be summer.
When you consider the other planets in our solar system, you find worlds that are bitterly cold or hotter than a pizza oven, swirling with poisonous gases. None can sustain life.Why then is the Earth so special? What regulates our climate so it stays moderate and consistent?
There are three main components that interact to regulate our climate: solar energy, the atmosphere (air), and the hydrosphere (water). As long as the main components of the climate system remain intact, the climate is fairly predictable. Our historically stable climate has allowed us to plan where to plant crops, build cities, create industries, manage water flows, and preserve wild ecosystems. But recent human activities have begun to change the components of this system, with dramatic and unforeseen consequences.
Climate components
Solar energy
The climate of the Earth is ultimately determined by solar energy: the amount of energy coming from the sun. The amount of solar energy hitting the Earth depends on how strongly the sun is burning and how that light is spread out on the Earth’s surface.
Small changes in Earth’s orbit and periodic changes in the sun’s energy output have caused ice ages and warm periods in the past. However, the amount of solar energy hitting the Earth does not change very quickly, so variation in solar radiation can’t account for the rapid changes we are now finding in our climate.
Atmosphere
The atmosphere is the blanket of gas (air) surrounding the Earth. It starts at ground level and reaches up about 100 km to the edge of space. The atmosphere is composed of many layers. The layer closest to the Earth’s surface is called the troposphere. This learning activity will focus on what happens in the troposphere.
Hydrosphere
About 70% of the Earth’s surface is covered by water. The term hydrosphere refers to all the water in the Earth system, including the water in oceans, lakes, rivers, and groundwater.
Oceans
97.5% of the Earth’s water is salty. The oceans make up a huge basin of water that can absorb a tremendous amount of heat. Oceans absorb and move heat around the globe in currents, which plays a big role in determining the Earth’s climate.
Freshwater
Only 2.5% of the hydrosphere is freshwater. Of that tiny percentage, 70% exists as glaciers and icecaps, 30% in groundwater, and 0.3% exists as lakes and rivers.
The study of the climate system is really the study of heat transfer. Let’s explore the various methods of transferring energy as heat across the planet.
Action Part 2: Heat transfer radiation: Transfers of heat energy
The Earth is warmed up by solar energy. Since the tropical zones are closer to the sun than the poles are, they get more solar energy and so are warmed up more. However, just like in a pot of boiling soup, the heat energy entering the Earth doesn’t just stay in one place. It gets moved around because heat always flows from the warmer areas to cooler areas.
There are three ways to transfer heat: radiation, conduction, and convection. All three ways of transferring heat occur when heating a pot over a campfire.
In this learning activity, you will examine each of these three methods and its relative importance in regulating our climate.
Radiation
Radiation is simply the transmission of energy. As it travels, light from the sun takes the form of an electromagnetic wave. It is able to travel through outer space. These electromagnetic waves from the sun deposit their radiant energy when they interact with some form of matter, such as the air in the atmosphere, the surface of the Earth, or your skin. There are many examples of electromagnetic waves, such as visible light, ultraviolet light, microwaves, radio waves, and X-rays. As you can find in the diagram, the difference between the types of electromagnetic waves is the length of the waves. As you move to the right on the diagram and the lengths get shorter, the radiation becomes more dangerous.
Example
If you place your hand near a flame, hot iron, or stove, the radiant energy travels from the hot object to your hand, as shown in the diagram. The radiant energy then interacts with your hand and is changed into heat (thermal energy), which your skin can detect.
What would you say to a friend who believes that all radiation is harmful?
Radiation is energy that is transmitted as electromagnetic waves. Although there are some forms of radiation that are very dangerous, even in small quantities, not all radiation is harmful. Light, heat, radio waves and sound waves are all experienced safely every day around the world.
When the radiant energy from the sun reaches the Earth, two things happen. Approximately 30% of this energy is reflected back into outer space. The remaining 70% is absorbed by the Earth’s surface (land and water) and air. Since most of the Earth’s surface is water, the interaction between radiant energy and water has a major influence on climate.
Albedo
The amount of radiant energy that is reflected by a surface is called the albedo. Any material that absorbs radiant energy is called a heat sink.
Not all material reflects or absorbs the same amount of solar energy. Even though water has a higher albedo than land (since water reflects more than soil), oceans are good heat sinks. This is because water can absorb much more radiant energy than land. In fact, water absorbs five times more energy than soil. As well, radiant energy can penetrate much deeper into water than it can on land. As a result, large bodies of water can absorb a great deal of energy with little change in temperature.
The following video provides detailed information on the albedo effect.
You can experiment with the albedo effect at home using soup cans and sunlight. Follow the steps provided in the document “Albedo and Radiant Energy (Opens in new window)” and complete the activity that follows.
Now that you’ve learned about how heat energy is transmitted as radiation, you’ll learn about two other methods of heat transfer: conduction and convection.
Heat energy transfer: Conduction
Conduction
Another method of transferring heat is conduction, which is the transfer of heat energy through the collisions of atoms in an object.
For example, a metal rod is made up of billions of vibrating atoms. If one end of the metal rod is held over a flame, the atoms in the flame become more energetic and vibrate more quickly. They collide with other nearby atoms, then they start to vibrate more quickly as well. This process continues along the rod from the hotter end towards the colder end. The atoms themselves vibrate in place and do not move along the rod – only the energy travels from one end of the rod to the other.
Example
Consider a metal rod with beads of wax evenly placed along the rod (as shown in the following diagram). For example, a metal rod is made up of billions of vibrating atoms. If one end of the metal rod is held over a flame, the atoms in the rod become more energetic and vibrate more quickly. They collide with other nearby atoms, then those start to vibrate more quickly as well. When heat is applied to one end of the rod, the beads of wax closest to the flame will melt first as the heat is conducted along the rod.
The material in which the energy is transferred is called the medium. In this case, the metal rod is the medium. Though radiation does not require a medium, conduction cannot take place without one. For conduction to occur, the particles must be in contact with each other.
You have probably experienced conduction when grabbing a hot pot handle on the stove. The handle conducts heat from the heated pot to your hand. Pot designers try to reduce this conduction by making the handles out of non-conductive material or by making sure the handle gets a lot of air around it to help it cool faster.
Conduction is a slow process and is not responsible for most of the heat transfer around the globe.
Explain how conduction is occurring when you walk barefoot on a sandy beach on a warm day.
When you are walking barefoot on a sandy beach on a warm day, the heat is transferred from the sand to your feet by conduction. As well, the air touching the warm sand is heated by conduction. This also happens to the air in contact with the warm water.
Finally, let’s explore the third method of heat energy transfer.
Heat energy transfer: Convection
A third method of transferring heat is convection, which is the transfer of heat energy in a fluid by the actual movement of the fluid’s particles from one place to another.
The term “fluid” can refer to either a liquid or a gas. In conduction, the particles vibrate but do not move to another location; in convection, the particles do change location.
This movement is brought about by different densities within the fluid. As shown in the accompanying image, if a pot of water is heated, the water molecules at the bottom of the pot are heated (thermal energy) by conduction because they are in contact with the hot bottom of the pot.
As this water heats up, the distance between the molecules expands and the water at the bottom of the pot becomes less dense. Since the colder water at the top of the pot is now denser than the warm water at the bottom, the colder water sinks and pushes the warm water upwards. This circulating path of moving water is called a convection current.
Action Part 3: Convection currents
Convection currents are also present in our oceans and atmosphere because both are fluids and the Earth is not evenly heated by the sun. The area around the equator is warmer than the polar regions because the sunlight strikes those areas more directly. Just as in a heated pot of chicken noodle soup, convection currents form both in the oceans and atmosphere. These currents transfer heat away from the equator and move it towards the colder poles.
Ocean currents carry warm water from the equator to the north and south polar regions. One current, called the Gulf Stream, carries warm water from the Caribbean north along the east coast of North America and then curves northeast towards England. Because of the Gulf Stream current, palm trees can grow in southern England even though the latitude there is the same as in Winnipeg.
You will explore the forces driving global and local convection currents in more detail in the next learning activity.
Local convection currents
Wind is the movement of air in the atmosphere as a result of convection currents. Some winds are local, occurring only in a relatively small region. Land breezes or water breezes (also called sea breezes) are an example of a local wind that can form on a warm day near a body of water such as a lake.
Examine the image depicting both a land and sea breeze. A water breeze occurs during the day when the solar energy warms up the land faster than the nearby water. As a result, the air above the land becomes warmer than the air above the water. This warm air rises faster over the land, which causes the colder, denser air off the lake to flow towards the land.
The direction of the wind reverses in the evening when a land breeze forms. As the sun sets, the land cools faster than the water, again because water is a better heat sink. Now the air above the water is warmer than the air above the land, and a convection current forms going from the land towards the water.
Another example of a local convection current that occurs during the day is called a thermal or thermal updraft. On a sunny day, over land areas, some parts get hotter than others because they have a lower albedo.
These updrafts are often strong enough to allow large birds like vultures and hawks to soar upwards in circles for hours. They use the thermals like elevators; they save energy by gaining altitude without having to flap their wings. Glider pilots also hunt for thermals to gain altitude.
Challenge
Now that you have achieved a strong understanding of Earth’s climate change, let’s apply the learning back to your surroundings. Consider the following question:
If you could change any specific activity to better the environment, which activity would it be and why? For example, you may decide to drive with your neighborhood friends together to the movies in one car. Take some time to build on your transferable skill in Self-Directed Learning by thinking about the answer or recording your answer in your notebook.
Try it!
Check your overall understanding of climate and heat energy transfer by answering this question.
For each definition select the corresponding term from the drop-down menu. Then press Submit to find out how you did.
Key concepts
The Key concepts (Opens in new window) will give you a refresher on the concepts provided over this learning activity.
Take a brief break and then review any concepts you have not fully understood.
Connecting to the transferable skills
Transferable skills
Recently, Ontario worked with other provinces in Canada to outline a set of competencies that are requirements to thrive. Ontario then developed its transferable skills framework as a set of skills for students to develop over time. These competencies are ones that are important to have in order to be successful in today’s world.
Read through the framework and the student look-fors (Opens in new window). Copy this document into your notes – you'll refer to it in each unit.
Note the indicators that you think you will develop in this course. At the end of the course you will revisit these skills to find out which ones you actually developed and if your original predictions were correct.
How to concentrate and focus on your studies
Notebook
While working through this course, you will need one other tool to help you stay organized. You will need a ‘notebook’.
This may be an actual pen and paper notebook where you can take notes and write reflections as instructed throughout the course. Alternatively, you may choose to have a digital ‘notebook’ or a file where you type your notes and reflections. This is a personal decision, but it is important that you have a consistent place for your notes.
Be sure to add a title to each set of rough notes with the unit you are working on, learning activity title and number. Spelling does not matter in these rough notes, but the act of completing these reflections and quick activities is important for your learning.
You will encounter questions throughout the course that ask you to pause and reflect on your learning, or to self-check. Record these questions and your answers in your notebook, then compare your response to the suggested answer if one is provided. Any differences are an opportunity to learn more, but as they are just suggestions, they do not mean your answers are wrong.
Career connection: Meteorologist
A career in relation to the Earth’s climate system is a Meteorologist. The Federal Government of Canada has provided the following description for this unique career:
Meteorologists analyze and forecast weather, provide consultation on atmospheric phenomena and conduct research into the processes and phenomena of weather, climate and atmosphere.
Self-check
Read the following descriptions and select which one best describes your current level of comfort toward the learning concepts in this learning activity. Copy the descriptions and the description that you have selected into your notebook. When you review your notes on this learning activity later reflect on whether you would select a different description based on revising the learning material.
Now that you have explored different components of climate and heat transfer, consider the following question to further develop the Transferable Skill in Citizenship and Communication:
If you could share three important highlights of how climate and heat transfer can impact your community, what would they be?
Culminating activity
At the end of this course, you will prepare and submit a culminating activity. Review the culminating activity description (Opens in new window) now and keep it in mind as you read articles and explore concepts in the course.
Challenge
Now that you have achieved a stronger understanding of climate change, consider any of the activities you take part in within your day. Does climate change impact any of your activities? For example, gardening or driving a car may be activities that you are interested in searching for. Take some time to build on your transferable skill in Self-Directed Learning by thinking about the answer or recording your answer in your notebook.
Congratulations
Congratulations! It’s time to celebrate. You have successfully completed the first learning activity in Unit 1.
So far, you have learned that life on Earth exists because of a carefully regulated climate. You have been introduced to the three main components regulating climate: solar energy, the atmosphere, and the hydrosphere. You have also learned how heat can be transferred across the globe in three ways, with convection being the most important for climate regulation
Next steps
In the next learning activity, you will study these processes in more depth. Once you understand what drives our climate system, you will learn more about how human activities change the system.
