SAERC

GGS 12

Mr. R. Allen

Global Warming: Some like it H.O.T.!(Higher Order Thinking)

Burning fossil fuels powers our world, but there seems to be a big price to pay for that power—the potential for global warming. Is global warming real?

There are different points of view on the causes of global warming, and about how serious the effects could be. Most scientists today believe that global warming poses a very real threat to people and the ecosystems they depend on, and that international and local strategies are urgently needed to encourage us to produce less of the greenhouses gases that are warming up the Earth.

Climate is a complex, little-understood system. Even the most experienced scientists really don’t know very much about the way the dynamic natural systems such as the oceans and atmosphere work, much less how they are interconnected. We do know that natural systems are self-sustaining, and that the oceans and atmosphere work together as interconnected parts of the biosphere. For example, cold air rushing over warm water currents creates fog.

The Hard Facts about Climate Change

Here are some key facts on which scientists agree.

About greenhouse gases

•Atmospheric concentrations of carbon dioxide (CO2) are now 30 per cent higher than in 1750. Concentrations of methane are now 150 per cent higher.

•Greenhouse gases make up less than 1 per cent of the atmosphere but control energy flows in the atmosphere by absorbing heat.

•Because some greenhouse gases persist in the atmosphere for hundreds or even thousands of years, the effects of emissions today will be felt far into the future.

•Wealthy industrialized countries contain about 20 per cent of the world’s population, yet they account for more than 65 per cent of the greenhouse gases produced by humans.

•One average-sized, coal-burning electric power plant generates 10 000 tonnes of nitrogen oxide (NOx) in one year; it would take 500 000 late-model cars to produce the same amount of NOx in the same amount of time.

Shrinking carbon sinks

•Carbon sinks are reservoirs that remove carbon from the atmosphere. They “clean” the air by absorbing carbon. The largest carbon sinks are oceans, forests, and permafrost.

•The ocean contains 50 times more carbon than the atmosphere does.

•Human activities such as deforestation are interfering with carbon sinks,

•Humans destroy about 13 million hectares of the forest carbon sink every year—an area about twice the size of New Brunswick.Temperature records

•The Earth warmed by 0.7°C over the twentieth century.

•The decade of the 1990s was the warmest on record.

•The last decade has seen nine of the warmest ten years since records began in 1861. In descending order of heat the five warmest-ever years were: 1998, 2003, 2002, 2004, 2001.

•The year 2003 was the eleventh consecutive year with higher-than-average temperatures.

Ocean and ice changes

•Sea level rose 10–20 cm over the twentieth century—it varies from place to place.

•The ocean is measurably warmer since observations began in the 1950s.

•Glaciers and polar ice sheets are melting, and the Antarctic Larsen B ice shelf collapsed in 2002.

•Arctic sea ice has thinned by 40 per cent since 1970.

•The hunting season that polar bears are dependent upon for food has been reduced by more than four weeks over the last 20 years because of diminishing ice cover; many polar bears are dying.

Weather changes

•Global precipitation has increased by 2 per cent since 1900.

•Freak storms are now more frequent. Consider the “weather bomb” that hit Halifax in February 2004: it dumped a record 95.5 cm of snow in one day.

•Other unnatural and extreme weather events such as longer or earlier storm seasons, stronger hurricanes, windstorms, and droughts are beginning to occur.

1.One point of view you would not expect to hear is that of aliens from outer space. Critically analyze the following cartoon. What is the main message conveyed by the artist? How does the message make you feel?

Part 1: The Greenhouse Effect

Most everyone has been in the uncomfortable situation of having to wait in a car on a hot summer day. The Sun beats down on the car, heating up the surfaces and air inside. The heat cannot escape from the enclosed car nearly as fast as it comes into the car. Stuck in the hot car, you are a victim of the greenhouse effect!

The atmosphere—with its greenhouse gases—is like a comfortable jacket wrapped around the Earth. Heat from the Sun warms up the atmosphere (the Earth’s jacket), and the jacket helps keep the heat in. Without greenhouse gases in the atmosphere, the Earth would be a very cold place! But too much of a good thing is always something to be cautious about.

2.Your Atlas can be a good research tool. Let’s see what it has to offer to help you understand the basics of climate change. Refer to the diagram showing the greenhouse effect on page 16 of the Atlas.

a)Briefly explain what happens to incoming radiation from the Sun.

b)Briefly explain what happens to heat escaping from the Earth.

c)The atmosphere of planet Earth is warmer near the ground and cooler higher up. Suggest a reason why the higher levels of the atmosphere are cooler than the lower levels of the atmosphere, despite being closer to the Sun.

d)In your own words, describe why the greenhouse effect is necessary to life on Earth.

Now that you have learned how the greenhouse effect maintains the heat of the atmosphere, think about what would happen if the concentration of greenhouse gases in the atmosphere increased. Would you sweat more in a jacket that doesn’t let out the heat?

That’s what’s happening today. Concentrations of greenhouse gases in the atmosphere are increasing, which means that less heat energy is able to escape out to Space. This puts the Earth’s natural temperature-control system out of whack. When this happens, global warming takes place.

Carbon dioxide (CO2) is the main greenhouse gas warming up the planet, but it’s not the only one. The ability of these gases to retain heat in the atmosphere varies widely. For example, nitrous oxide (N2O) molecules absorb 270 times as much heat as carbon dioxide molecules do.

3.Use the table on page 128 of the Atlas to discover the five major groups of greenhouse gases. Complete the first column in the table on the next page by ranking the gases in order of their importance to global warming. Then fill in the rest of the columns using information from the Atlas chart.

Greenhouse Gas / Percentage of Contribution to Global Warming / Human Activities Producing It
(Anthropogenic sources) / Lifetime in Atmosphere
Carbon dioxide (CO2) / 54%

4.Refer to the map on page 128 in the Atlas, Carbon dioxide emissions 2005. Why do you think the map shows carbon dioxide emissions, but not the other four greenhouse gases in your chart?

5.Choose one or more of the gases listed below to research. Follow the instructions and present your findings in chart form, as shown in the example.

Gas with a Direct Effect on Global Warming
/
Gas with an Indirect Effect on Global Warming
•Perfluorocarbons (e.g.,
hexafluoroethane, C2F6)
•Sulphur hexafluoride (SF6) / •Water vapour (H2O)
•Carbon monoxide (CO)
•Volatile organic compounds
(VOC) (non-methane)
•Sulphur dioxide (SO2)

a)Identify the main human activities responsible for increasing the production of your assigned gas.

b)Write a brief analysis of the potential of each gas to contribute to warming the global atmosphere. Note: You may wish to seek out the global warming potential (GWP) figures, available from the Intergovernmental Panel on Climate Change (IPCC) at

c)Finally, write down the most interesting fact about the greenhouse gas you were assigned. For an example, see the analysis of carbon dioxide below.

Greenhouse Gas / Human Activities Producing It / Potential for Global Warming
Carbon dioxide (CO2) / •burning fossil fuels
•burning biomass (plant and animal waste)
•changes in land use, such as forest to agriculture (deforestation)
•producing metals
•producing lime to make cement (a major industrial contributor) / •lowest ability to trap heat but is being added in high amounts
(4 per cent annually)
Most Interesting Fact: It’s been in the Earth’s atmosphere for four billion years!

Part 2: Global Emission Patterns

6.For the most part, greenhouse gases are created when we use energy. Some forms of energy, such as wind power, do not create greenhouse gases. Denmark employs more than 20 000 people in the wind-energy business, and produces almost 20 per cent of its electric power from windmills. That percentage is expected to rise to 50 per cent by 2030. But no country in the world uses clean energies exclusively. So, which countries are the world’s biggest fossil-fuel energy users? In the following section you will use several graphs and maps in the Atlas to analyze the connections between global energy patterns, industrialization, and carbon dioxide emissions.

a)Refer to the map Carbon dioxide emissions, 2005 at the top of page 128 in the Atlas. List the six countries that show the greatest level of carbon dioxide emissions per person. (Do not copy the list from the yellow table below the legend. It shows the highest carbon dioxide emissions overall, not per person.) You may wish to refer to the political map of the world on pages 118–119 of the Atlas to help you identify the countries. Underneath your list, write down your idea of why these six countries might have the highest emission levels in the world.

b)Refer to the circle graph Global CO2 emissions by sector at the bottom of Atlas page 128. Which sector creates the most global CO2 emissions?

c)Examine the map of Electricity production on the bottom of page 145. What general similarities can you observe between this map and the map of carbon dioxide emissions on page 128? Complete this statement:

Generally speaking, countries with low electricity production tend to have ______carbon dioxide emissions, and countries with high amounts of electricity production tend to have ______carbon dioxide emissions.

d)You may notice that the relationship is not absolute, and that some countries do not fit the pattern. Why might this be the case?

e)There is obviously a relationship between electricity production and carbon dioxide emissions. Refer to the maps of Oil, Gas, and Coal production on Atlas pages 144 and 145 to determine which three fossil fuels are being used to create this electricity.

f)Let’s examine what other factor we should consider when looking at the causes of global warming. Refer to the map of Industrialization, 2006 at the top of Atlas page 142. Does this map resemble the other two maps you have examined? Refer to the circle graph on the bottom of page 128 to explain the connection you see.

g)Finally, refer to the Atlas maps of Purchasing power, 2005 and Human Development Index, 2005 at the top of pages 138 and 139 respectively. Do these maps follow the same general pattern as the maps of Electricity production (page 145), Industrialization, (page 142) and Carbon dioxide emissions (page 128)? Write a short paragraph that details why these maps look very similar to one another.

h)Suggest three reasons why Canada has such a high rate of carbon dioxide emissions.

7.There are complex relationships between levels of industrialization, numbers in population, levels of standard of living, and levels of carbon dioxide emissions. Create a concept map that shows how these four variables could interact with each other. Remember that a concept map is different from a word web in that it uses

•colour and font sizes to help organize ideas

•images to assist in the communication of ideas

•links and connectors to show how ideas interact

•descriptive linking phrases on the connectors to describe how ideas interact

The reader should be able to get a clear picture of how the four variables could impact each other, and what the relationships among them are.

Part 3: Taking Action for the Future

Resolve to create a good future. It’s where you will spend the rest of your life.

—Charles Franklin Kettering

Climate change is a “hot” issue on a global scale, and many people in the world have contributed to the problem in one way or another. Who is responsible for protecting the natural environment on which we all depend for our survival? If you live in a country that you would classify as one of the world’s highest contributors of greenhouse gas emissions, then you have a particular responsibility. You might ask, what difference can one person make? You can take responsibility, you can get involved, you can take action, and you can set an example. You may not be able to save the world in one fell swoop, but to save things everywhere you can start by saving them somewhere—in your home and community.

Most scientists agree that the amount of greenhouse gases in the atmosphere is increasing, as is the average temperature on the planet. No one really knows, however, what the future in a warming world will bring, and few can agree about what we should do about it. Most disagreement centres on how much of the Earth’s warming trend has resulted from human activities such as the burning of oil, natural gas, and coal. Scientists also disagree on how serious the impact will be on people and the natural environment in different parts of the world. These questions are important, as the answers will help us decide whether or not we should be changing our behaviour.

More than 2000 scientists from around the world (the IPCC scientists) have criticized a small group of people who are skeptical about climate change. These skeptics disagree with the majority of scientists on the degree to which human behaviour is affecting the warming trend, and also on the seriousness of its potential impact. They have been accused of having dubious motivations. If an oil company is funding your research program, are you likely to criticize it? Some politicians have been accused of manipulating and suppressing scientific information. For example, the US Environmental Protection Agency was instructed to leave climate change out of a comprehensive report on environmental issues.

Consider some of the various opinions in the next questions, and judge for yourself whom you agree with.

8.Is climate change real? Why does this issue set off such heated debate? Read the following quotes and use the chart on the next page to evaluate each speaker’s position.

Who is the speaker? / What is their position on climate change? / What factors might be influencing this position?

Three Opinions about Climate Change

The changes we need to make to fight greenhouse gas emissions and stop climate change are changes that would make us all better off even if climate change was not happening. An environmentally responsible future without fossil fuels is a healthier future.

—member of an environmental non-governmental organization (NGO)

The global climate has always changed back and forth and will do so regardless of the gases we put into the atmosphere. Computer models of general atmospheric change are based on unrealistic hypotheses and ignore important feedback mechanisms. Humans just don’t have that much influence. Global warming has been grossly exaggerated by the media, the governments of developing countries, and scientists who are willing to be less than objective in order to get government research grants.

—professor of atmospheric science who works for a conservative public policy NGO

There is no evidence that the Kyoto Protocol will be effective in reducing greenhouse gas emissions. The costs of reducing carbon emissions would be astronomical and would cause economic hardship for little gain.

—spokesperson for a lobby group funded by oil companies

9.What is your position on climate change? What factors influence your position?

10.What kind of a future are we in for? Before people will take effective action to reduce greenhouse gas emissions, they need to imagine what their future, living on a warmer planet, will probably be like. The changes listed in “The Hard Facts about Climate Change” at the beginning of this activity give us just a taste of what the future could bring. While no one can know for sure what the future will hold, scientists and futures analysts use a number of techniques to make predictions in order to prepare and plan for possible alternative futures. Here are the predictions of two organizations.

Predictions of the Canadian National Energy Board

•By 2025, Canada’s population will increase by about 15 per cent, yet its demand for energy will increase by about 34 per cent.

Predictions of the United Nations

•Global temperatures are expected to rise by at least 3.6°C and possibly as much as 5.8°C by 2100.

•Temperature changes will be most extreme in the northern latitudes.

•About 150 million environmental refugees will be searching for new homes by 2050.

•Warming temperatures will have a huge impact on ecosystems, wiping out 25 per cent of all plant and animal species by 2050. This mass extinction will kill more species than the mass extinction that wiped out the dinosaurs 65 million years ago.

•If the Greenland ice sheet melts completely, sea levels will rise an additional 3 m.

•Most coral reefs and their ecosystems will disappear.