The Greenhouse Effect and Global Climate Change
Before commencing the activities in this booklet you should watch the video ‘An Inconvenient Truth’, which can be accessed by clicking on the following link: An Inconvenient Truth
What is the Greenhouse Effect?
The greenhouse effect is the rise in temperature that the Earth experiences because certain gases in the atmosphere (water vapour, carbon dioxide, nitrous oxide, and methane, for example) trap energy from the sun. Without these gases, heat would escape back into space and the Earth’s average temperature would be about 15°C colder than it is currently. Because of how they warm our world, these gases are referred to as greenhouse gases, as they work in very much the same way as a greenhouse.
Have you ever seen a greenhouse? Most greenhouses look like a small glass house. Greenhouses are used to grow plants, especially in the winter. Greenhouses work by trapping heat from the sun. The glass panels of the greenhouse let in light but keep heat from escaping. This causes the greenhouse to heat up, much like the inside of a car parked in sunlight, and keeps the plants warm enough to live in the winter.
Activity 1 – You can type in the box, which will expand as you type
Define “The Greenhouse Effect”.
How does the Greenhouse Effect work?
The Earth’s atmosphere is all around us. It is the air that we breathe. Greenhouse gases in the atmosphere behave much like the glass panes in a greenhouse. Sunlight enters the Earth's atmosphere, passing through the blanket of greenhouse gases. As it reaches the Earth's surface, land, water, and biosphere absorb the sunlight’s energy. Once absorbed, this energy is sent back into the atmosphere. Some of the energy passes back into space, but much of it remains trapped in the atmosphere by the greenhouse gases, causing our world to heat up.
The greenhouse effect is important. Without the greenhouse effect, the Earth would not be warm enough for humans to live. But if the greenhouse effect becomes stronger, it could make the Earth warmer than usual. Even a little extra warming may cause problems for humans, plants, and animals.
Activity 2
Explain how the Greenhouse Effect Works. You may use your textbook and the video, ‘An Inconvenient Truth to help you’
Activity 3
Describe what would happen to the Earth if the Greenhouse Effect did not exist
The Greenhouse Gases
Many gases exhibit “greenhouse” properties and are therefore referred to as greenhouse gases. Some of them occur naturally (water vapor, carbon dioxide, methane, and nitrous oxide), while others are exclusively human-made (like Chlorofluorocarbon gases, CFC’s, used for aerosols).
Levels of several important greenhouse gases have increased by about 25% since large-scale industrialization began around 150 years ago. During the past 20 years, about three-quarters of anthropogenic (human-made) carbon dioxide emissions were from burning fossil fuels.
Can humans change climate?
It may seem hard to believe that people can actually change the Earth’s climate. But scientists think that the things people do that send greenhouse gases into the air are making our planet warmer.
Once, all climate changes occurred naturally. However, during the Industrial Revolution, we began altering our climate and environment through agricultural and industrial practices. The Industrial Revolution was a time when people began using machines to make life easier. It started more than 200 years ago and changed the way humans live. Before the Industrial Revolution, human activity released very few gases into the atmosphere, but now through population growth, fossil fuel burning, and deforestation, we are affecting the mixture of gases in the atmosphere.
Since the Industrial Revolution, the need for energy to run machines has steadily increased. Some energy, like the energy you need to do your homework, comes from the food you eat. But other energy, like the energy that makes cars run and much of the energy used to light and heat our homes, comes from fuels like coal and oil – fossil fuels. Burning these fuels releases greenhouse gases.
Major sources of greenhouse gases
So what is Global Warming?
Global warming is an increase in average temperature of the Earth’s atmosphere. It is thought that the increase in greenhouse gases owing to human activity such as the burning of fossil fuels is directly responsible for increasing the Earth’s average temperature over the last 100 years.
When Do You Send Greenhouse Gases into the Air?
Whenever you ...
· Watch TV
· Use an air conditioner
· Turn on a Light
· Use a hair dryer
· Ride in a Car
· Play a Video Game
· Listen to a Stereo
· Wash or Dry Clothes
· Use a Dish Washer
· Microwave a Meal
... you are helping to send greenhouse gas into the air.
To perform many of these functions, you need to use electricity. Electricity comes from power plants. Most power plants use coal and oil to make electricity. Burning coal and oil produces greenhouse gases.
Other things we do send greenhouse gases into the air too;
The trash that we send to landfills produces a greenhouse gas called methane. Methane is also produced by the animals we raise for dairy and meat products and when we take coal out of the ground. Whenever we drive or ride in a car, we are adding greenhouse gases to the atmosphere. And, when factories make the things that we buy and use everyday, they too are sending greenhouse gases into the air.
Greenhouse Gas Emissions in Australia
Greenhouse Gas Emissions (Gigagrams of CO2 equivalents (CO2-e).) / Percentage Share of Total Greenhouse Gas EmissionsAgriculture; hunting & trapping; forestry & fishing / 7,188
Mining / 15,136
Manufacturing / 57,166
Electricity and gas / 169,562
Construction / 4,958
Transport / 30,939
Services / 9,063
Household production / 9,063
Total / 339,597
Activity 4
Complete the above table and draw a pie chart using Microsoft Excel to show the source of greenhouse gas emissions in Australia.
How do fossil fuels contain carbon?
Coal, oil and gas are the three fossil fuels that we burn, which in turn sends several tonnes of CO2 into the atmosphere every day. But why do these fuels contain so much carbon? If you think back to your understanding of the carbon cycle, CO2 is removed from the atmosphere through plant respiration. It is this intake of carbon by plants that led to the development of fossil fuels several thousand years ago. The diagram below, explains it simply:
Activity 5
When humans add more greenhouse gases to the atmosphere it often causes “The Enhanced Greenhouse Effect”. Describe what is meant by the term “The Enhanced Greenhouse Effect”.
Activity 6
Make a large copy of the table below and complete it with the details on how humans contribute to the Greenhouse Effect. Use your textbook to help you.
Greenhouse Gas / Source of the Greenhouse Gas / Ways in which humans add this Greenhouse Gas into the AtmosphereWhat is the evidence of global warming?
The graph below shows the variation from the global average temperature over the past 130 years. It is possible to see from the graph that year temperatures were below the world average up until about 1960, with the exception of a small period above average around 1940. Since 1960, on the whole the yearly global average temperature has risen significantly above the average temperature for the past 130 years. It has risen to nearly 0.5 °C above the world average over the last five years, which is concerning.
Similarly, if we look at carbon dioxide concentrations in the atmosphere since 1960 in the graph below, we see a continued rise. This has led scientists to believe that humans increasing greenhouse gases in the atmosphere, particularly CO2, is leading to global warming and climate change.
Activity 7
Study the graphs below. Describe the trends in global temperatures and greenhouse gas emissions since 1960.
The future influence of the Enhanced Greenhouse Effect on the World’s Climate and Human Lives
What Might Happen? It is important to understand that scientists don't know for sure what global warming will bring. Some changes brought about by global warming will be good. If you live in a very cool climate, warmer temperatures might be welcome. Days and nights could be more comfortable and people in the area may be able to grow different and better crops than they could before. But it is also true that changes in some places will not be very good at all.
Human Health
Climate change may affect people's health both directly and indirectly. For example, heat stress and other heat related health problems are caused directly by very warm temperatures and high humidity. Untreated, heat stress can be a very serious medical problem. Scientists suspect that, in many places, global warming will increase the number of very hot days that occur during the year. More hot days increases the possibility of heat related health problems.
Indirectly, ecological disturbances, air pollution, changes in food and water supplies, and coastal flooding are all examples of possible impacts that might affect human health.
How people and nature adapt to climate change will determine how seriously it impacts human health. Some people and places are likely to be affected more than others. Generally, poor people and poor countries are less likely to have the money and resources they need to cope with preventing and treating health problems. Very young children and the elderly adults will run the highest risks.
Ecological Systems
Climate change may alter the world's habitats and ecosystems – all living things are included in and rely on these places. Many of these places depend on a delicate balance of rainfall, temperature, and soil type. A rapid change in climate could upset this balance and seriously endanger many living things.
Most past climate changes occurred slowly, allowing plants and animals to adapt to the new environment or move somewhere else. However, if future climate changes occur as rapidly as some scientists predict, plants and animals may not be able to react quickly enough to survive. The ocean's ecosystems also could be affected for the same reasons.
Sea Level Rise
Global warming may make the sea level become higher. Why? Well, warmer weather makes glaciers melt. A glacier is a large sheet of ice that moves very, very slowly. Some melting glaciers add more water to the ocean. Warmer temperatures also make water expand. When water expands in the ocean, it takes up more space and the level of the sea rises.
Sea level may rise between several inches and as much as 3 feet during the next century. This will effect both natural systems and manmade structures along coastlines. Coastal flooding could cause saltwater to flow into areas where salt is harmful, threatening plants and animals in those areas. For example, an increase in the salt content of the Delaware and Chesapeake bays is thought to have decreased the number of oysters able to live in those waters.
Oceanfront property would be affected by flooding, and beach erosion could leave structures even more vulnerable to storm waves. Whether we move back from the water or build barricades in the face of a rising sea, it could cost billions of dollars to adapt to such change. Coastal flooding also may reduce the quality of drinking water in coastal areas.
Crops and Food Supply
Global warming may make the Earth warmer in cold places. People living in these places may have a chance to grow crops in new areas. But global warming also might bring droughts to other places where we grow crops. In some parts of the world, people may not have enough to eat because they cannot grow the food that they need.
Activity 8
Use the table on the next page to prepare notes to discuss the effects of global warming for various places around the world. You should clearly show the possible effects of different climatic scenarios on the environment, the economy and society. Use the ‘An Inconvenient Truth’ video and your textbook to support your notes.
Impacts of global warming owing to the effects of the enhanced greenhouse effect
Positive impacts / Negative impactsEnvironmental impacts
Economic impacts
Social impacts
Countries and Regions producing the most CO2 Emissions
Region/Country / CO2 Emissions / Region/Country / CO2 Emissions Per Capita (Million Metric Tonnes)World Total
/ 25,162.07 / United States / 19.95Asia & Oceania / 8,173.74 / Australia / 19.10
North America
/ 6,808.20 / Canada / 19.05United States / 5,802.08 / Netherlands / 16.07
Western Europe
/ 3,895.76 / Brunei / 14.97China / 3,540.97 / Seychelles / 14.55
Eastern Europe & Former U.S.S.R. / 3,099.33 / Estonia / 13.89
Russia / 1,606.42 / Belgium / 13.66
Japan / 1,205.54 / Saudi Arabia / 13.52
Middle East
/ 1,203.21 / Taiwan / 12.40India / 1,024.83 / Bahamas, The / 11.26
Central & South America / 1,023.97 / Russia / 11.21
Africa
/ 957.85 / Czech Republic / 10.94Germany / 842.03 / Denmark / 10.94
Canada / 600.18 / Israel / 10.56
United Kingdom / 564.56 / Iceland / 10.41
Korea, South / 469.53 / Finland / 10.41
Italy / 465.48 / Cyprus / 10.26
South Africa / 411.25 / Ireland / 10.26
France / 409.18 / Germany / 10.21
Mexico / 404.72 / Norway / 9.93
Australia / 376.83 / New Zealand / 9.91
Iran / 372.00 / Korea, South / 9.84
Brazil / 351.46 / Puerto Rico / 9.80
Ukraine / 345.87 / Kazakhstan / 9.72
Spain / 339.71 / United Kingdom / 9.53
Saudi Arabia / 327.41 / Greece / 9.50
Indonesia / 318.35 / Japan / 9.44
Poland / 286.17 / South Africa / 9.13
Taiwan / 280.32 / Hong Kong / 9.08
Netherlands / 259.58 / Libya / 8.96
Turkey / 204.17 / Austria / 8.92
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