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Project Brief

The "Bringing Science to Life" Program was initiated by the Saskatchewan Science Teachers' Society to provide students and teachers with the most current information about important environmental issues. One of the first projects was about the increasing greenhouse effect and global warming, "Global Warming, Greenhouse Effect and the Canadian Prairies."

The purpose of the program is to involve students and teachers with current scientific knowledge and with the nature of that knowledge, that is, its interpretive, uncertain, and socially constructed nature. The human and up-to-date aspects of scientific knowledge are best conveyed by experts who participate in the construction of that knowledge and who use the knowledge in real life situations. The long-term goal is to develop an ongoing program to enhance the school science programs. Details of the program and its objectives are presented. The program was guided by a Steering Committee and tested by means of workshops held in Rosetown and Langham, Saskatchewan.

This manual was developed for grades 10 to 12 science based on the learning objectives presented in the Science 10 Curriculum Guide (Saskatchewan Education 1991). The "Greenhouse Effect" is Topic A-2 of Core Unit A: Earth/Environmental Science of the Science 10 Curriculum Guide (Saskatchewan Eduction 1991). The learning objectives listed in Topic A-2 (Saskatchewan Education 1991:86) are cross-referenced by being listed beside relevant questions and sections of the Instructor's Guide herein. Several of the factors of scientific literacy (Core Unit A: Earth/ Environmental Science of Saskatchewan Education 1991:84) can be addressed through the use of the material in this manual.

This manual contains a set of learning materials developed for the global warming and greenhouse effect phase of "Bringing Science to Life." It includes a detailed instructor's guide and supporting materials. The supporting materials consist of a bibliography, action list, graphics, student activities, a note on environmental ethics and global warming, and a glossary. Although work regarding ethical responsibility and global warming is at an early stage, it is an essential part of determining and evaluating responses and preparatory actions.

The instructor's guide includes an introduction to:

• changes in the Earth's atmosphere;
• past, present and future climates;
• possible effects of a warmer climate;
• suggested actions needed regarding a changing atmosphere and climate; and
• career opportunities in climatology and global environmental change.

The introduction section of the instructor's guide includes background information on the global changes of the planet's atmosphere, and discusses the greenhouse effect and its links to climate. The next part includes a description of past global and prairie climate changes, a discussion of future possible climates and how they are modelled. A set of actions needed is included so that the students know that they can improve the situation. The information is provided from regional, national and international perspectives. An evaluation form is included for improvements of further applications of the learning materials.

Global warming is only the first of many topics planned to be addressed in the "Bringing Science to Life" Program. Learning materials and activities are planned for the development for several other environmental issues, including waste management, conservation, plant ecology and biotechnology.

Table of Contents

Acknowledgements

The "Bringing Science to Life" Program was initiated by the Saskatchewan Science Teachers' Society and was coordinated by the Saskatchewan Research Council (SRC). The program was co-sponsored by the Saskatchewan School Trustees Association, Saskatchewan Wheat Pool, the Royal Bank of Canada, Saskatchewan Environment and Resource Management, the Saskatchewan Science Teachers' Society, and the Saskatchewan Research Council (SRC).

We thank the Steering Committee for their guidance and support. The Steering Committee consisted of representatives from the Saskatchewan Science Teachers' Society, Saskatchewan Education, the Saskatchewan School Trustees Association, Saskatchewan Environment and Resource Management, the College of Education and Extension Division (University of Saskatchewan), Awareness, Science and Technology, and Education Program Inc. (A-STEP), Saskatchewan Economic Development, and the Saskatchewan Research Council. Representatives were B. Mitschke, G. Aikenhead, P. Jonker, D. Matthews, A. Wileniec, H. Kurz, M. Valliaho, E. Wheaton, P. Greenidge, D. Norman, D. Potts, J. Duerksen, D. Keith, and K. Horsman. The committee was chaired by J. Konecsni (SRC). J. Duerksen, Milden Central School, Milden hosted the first workshop in Rosetown, Saskatchewan. D. Adams, W.W. Brown School, Langham held the second workshop in Langham, Saskatchewan.

The editors and authors thank G. Aikenhead, B. Bashutski, and B. Mitschke for their reviews of this manual. D. Adams, W.W. Brown School, Langham and J. Duerksen, Milden Central School, Milden tested and made suggestions to improve the student activity on shifting ecological climates. We thank C. Kreutzweiser, a Grade 11 student at Walter Murray Collegiate, Saskatoon, who reviewed the guide as part of his global warming project.

Word processing was done by Y. Wilkinson, M. McAree, and V. McQueen of SRC. Figures were redrawn and the cover was designed by C. Beaulieu, SRC. We thank Y. Wilkinson of SRC for her editorial work.

The cover picture is courtesy of Allan King, Ottawa Citizen.

The views and recommendations expressed herein were drawn from the literature by the authors and are not necessarily those of the Sponsors or of the Steering Committee.

Table of Contents

List of Contributors

Editors:

E.E. Wheaton, Lead Scientist, Climatology Section, Saskatchewan Research Council (SRC), 15 Innovation Blvd., Saskatoon, Saskatchewan, S7N 2X8; also Adjunct Professor, Geography Department, University of Saskatchewan.

J. Konecsni, Vice-President, Corporate Services, Saskatchewan Research Council (SRC), 15 Innovation Blvd., Saskatoon, Saskatchewan, S7N 2X8.

J. Duerksen, Principal, Milden Central School, Milden, Saskatchewan, S0L 2L0.

D. Adams, Science Teacher, Walter W. Brown School, Box 260, Langham, Saskatchewan, S0K 2L0.

P. Greenidge, Communications Officer, Communications, Corporate Services, Saskatchewan Research Council, 15 Innovation Blvd., Saskatoon, Saskatchewan S7N 2X8.

Authors:

E.E. Wheaton, Lead Scientist, Climatology Section, Saskatchewan Research Council (SRC), 15 Innovation Blvd., Saskatoon, Saskatchewan, S7N 2X8; also Adjunct Professor, Geography Department, University of Saskatchewan.

J. Duerksen, Principal, Milden Central School, Milden, Saskatchewan, S0L 2L0.

P. Greenidge, Communications Officer, Communications, Corporate Services, Saskatchewan Research Council, 15 Innovation Blvd., Saskatoon, Saskatchewan S7N 2X8

J. Konecsni, Vice-President, Corporate Services, Saskatchewan Research Council (SRC), 15 Innovation Blvd., Saskatoon, Saskatchewan, S7N 2X8.

Table of Contents

Introduction and Scope

E.E. Wheaton, J. Konecsni and P. Greenidge
 

Introduction

The "Bringing Science to Life" Program was initiated by the Saskatchewan Science Teachers' Society as a way to provide students and teachers with the most recent information about important environmental issues. Another objective was to bring scientists into the classrooms to enhance the knowledge, information and appreciation of students and teachers. One of the first projects selected for the "Bringing Science to Life" program was the "Global Warming, Greenhouse Effect and the Canadian Prairies" portion.

This report consists of learning materials developed for the Global Warming phase of "Bringing Science to Life." It includes factual information, suggested learning activities and support materials.
 

How does this Manual fit within the Curriculum?

A first question that teachers may ask is: How does this guide "fit" into the curriculum? This section addresses this question and provides suggestions for using this guide in that context.

Curriculum Integration

This manual was developed for grades 10 to 12 science based on the learning objectives presented in the Science 10 Curriculum Guide (Saskatchewan Education 1991). The basic material, however, can be adjusted to different levels as required. The guide was tested and improved based on the workshops, discussions and evaluations with grades 10 and 11 students and teachers (see Methodology for Development..., page 4).

The "Greenhouse Effect" is Topic A-2 of Core Unit A: Earth/Environmental Science of the Science 10 Curriculum Guide (Saskatchewan Eduction 1991). The learning objectives listed in Topic A-2 (Saskatchewan Education 1991:86) are cross-referenced by being listed beside relevant questions and sections of the Instructor's Guide herein.

Several of the factors of scientific literacy (Core Unit A: Earth/ Environmental Science of Saskatchewan Education 1991:84) can be addressed through the use of the material in this manual. For example, the factor "cause and effect" is illustrated through human activities causing increases in atmospheric carbon dioxide which then affect the carbon budget. The factor "questioning" occurs throughout the Instructor's Guide through the use of questions to frame the material, to the questioning of the scientific information presented by asking "What should we believe?" and "What are the key uncertainties and further work required?". The factor "interpreting data" is addressed through the presentation and discussion of many graphs, including time changes of carbon dioxide, methane, temperatures and precipitation.
Many of the abilities related to the "foundational objectives for science and the common essential learnings" listed in Saskatchewan Education (1991:84) can be increased by the use of the material herein. For example, this material can be used to increase students' abilities to "appreciate the complexity within natural systems; examine the impact of historical and contemporary human activity on the biosphere; identify ways that the impact of human activity can be reduced; analyze the environmental impact of personal activities and lifestyles; analyze the effect/impact of the environment on personal activities and lifestyles; and the effect of personal activities on the environment." The instructor is encouraged to emphasize the factors of scientific literacy as well as the "foundational objectives for science and the common essential learnings."

Suggestions for Using these Materials

The Instructor's Guide is the key part of this report. It consists of sets of questions and answers. Questions that are related to the learning objectives of the Science 10 Curriculum Guide (Saskatchewan Education 1991:86) are labelled accordingly. Each question is followed by notes for the instructor regarding possible answers. The instructor's notes are very brief replies to the questions. More complete answers could be developed by the students through their research work. The answers are based on the most recent published and reviewed work, but they should be updated with new findings as they become available.

The Instructor's Guide (page 5) contains cross-references to other parts of the report which are support materials. The support materials consist of a Student Program Evaluation (page 27); References and Further Reading (page 31); as well as the following appendices: Suggested Student Activities; A Note on Ethical Responsibility and Global Warming; a Climatic Change Glossary; and Figures (masters for overheads or other uses such as handouts).

This report material was designed for flexibility of use. The uses include:

• stand alone materials and activities for high school teachers to choose from to supplement the Grade 10 Science Curriculum on the greenhouse effect;
• supplementary materials for workshops delivered by a teacher/scientist or engineer (the workshop or presentation could be live or video-taped);
• support materials for interaction satellite broadcasts with an instructor or a panel.
 

Program Goals and Objectives

The purpose of the program is to involve students and teachers with current scientific knowledge and with the nature of that knowledge, that is, its interpretive, and socially constructed nature as well as its uncertainties and certainties. The human and up-to-date aspects of scientific knowledge are best conveyed by experts who participate in the construction of that knowledge and who use the knowledge in real life situations.

The long-term goal is to develop an ongoing program to enhance the school science programs.

The specific program objectives are to:

1) Provide students and teachers access to current and relevant scientific knowledge and information.

2) Provide opportunities for students and teachers to experience first hand the application of science and technology.

3) Help to demystify scientists, science and technology.

4) Help to keep the schools' science curricula current.

5) Provide teachers with learning activities and materials that can be used in the classroom on an ongoing basis, not just for the trial workshops.

6) Provide positive career role models in the sciences.
 

Objectives of the Manual

The learning materials encourage students to:

1) Improve their understanding of the "greenhouse effect."

2) Learn about past, present and future climate change.

3) Learn about the implications of climatic change for the Earth, especially Canada and the Canadian Prairies.

4) Develop awareness of the importance of actions to minimize the unprecedented growth rates of trace gases.

5) Understand what types of actions are needed to reduce net emissions of the greenhouse gases.

6) Acquire a sense of the uncertainties involved in science, including the need to make assumptions.

These objectives are designed to complement, clarify and build upon the learning objectives in the Science 10 Curriculum Guide (Saskatchewan Education 1991).

Organization of the Manual

This manual includes a project brief, an instructor's outline with teacher notes, student activities, a note on ethical responsibility and global warming, lists of recommended actions, a bibliography of suggested readings, examples of career opportunities, a glossary, equipment demonstration suggestions, an evaluation form, and graphic masters for overheads or handouts (for example).
 

Methodology for Development of the Manual - Workshops and Workshop Evaluation

A Steering Committee (see Acknowledgements, page ii) provided advice, support and guidance for the program. The workshop materials were tested during two workshops - one at Rosetown, Saskatchewan on June 5, 1992 and the other at Langham, Saskatchewan on March 3, 1993.

At these workshops, E. Wheaton, a climatologist at the Saskatchewan Research Council with expertise in global climate change, spent a day with a group of Grade 11 science students in Rosetown and a half day with Grade 10 science students in Langham. Discussions and activities were facilitated by the science teachers, J. Duerksen (in Rosetown) and D. Adams (in Langham), and by P. Greenidge, Saskatchewan Research Council.

The scientist shared the results of the most current research activities, and along with the teachers, involved the group in discussions and learning activities. Improvements were made on the initial draft materials based on results of the evaluation form administered at the workshop trials, comments from the "Bringing Science to Life" Committee, and others (see Acknowledgements, page ii). The Student Program Evaluation form (page 27) follows the Instructor's Guide.
 

Future of the Program

The global warming issue is only the first of many topics planned to be addressed in the "Bringing Science to Life" Program. In keeping with its environmental focus, learning materials and activities are planned for development in the areas of waste management, conservation, plant ecology, and biotechnology. These subject areas were identified by the Saskatchewan Science Teachers' Society. Scientists from organizations such as the Saskatchewan Research Council and the Saskatchewan Wheat Pool could provide the scientific expertise.

Table of Contents

Instructor's Guide

GLOBAL WARMING, THE GREENHOUSE EFFECT
AND THE CANADIAN PRAIRIES

E.E. Wheaton
 

Introduction - Changes in the Earth's Atmosphere

Why study changes to the Earth and the implications for the inhabitants?

Introduce the Earth as our life support system and "home place." The Earth is our life support system. We have found no better place to live. We depend on the air, water, soil, vegetation, animals, and other resources of the planet.
 

Introduce the global changes of the planet's atmosphere, land and water.

Humans have been changing the air, water, soil, vegetation, animals, and other aspects of ecosystems for long time periods. The chemical composition of the atmosphere is substantially different than it was just a century and a half ago. For example, we are certain that the atmosphere has been and is being changed at an unprecedented rate by trace gases that result from many human related activities. Although these gases occur in relatively small amounts, they have an important role in the Earth's climate.
 

What changes in atmospheric composition have occurred?
(Learning Objective A-2.3)

Emissions resulting from human activities are substantially increasing the atmospheric concentrations of the greenhouse gases, including carbon dioxide, methane, chlorofluorocarbons, and nitrous oxide (Figure 1). Present day atmospheric carbon dioxide concentrations are greater than 350 ppmv (parts per million by volume). This value exceeds the highest values of the past 160 000 years by more than 20%. Methane concentrations are approximately double the pre-industrial levels (Figure 2). Nitrous oxide has increased about 5 to 10% (Hengeveld 1991). Synthetic chemicals, such as chlorofluorocarbons (CFCs), which are not normally found in the atmosphere, are also increasing (e.g., Flavin 1989).

Figure 1 Annual atmospheric CO2 concentrations during the past 160 000 years. (derived from the Vostok and Siple ice cores and Keeling's Mauna Loa record [after Boden et al. 1990:3])

Figure 2 Annual atmospheric CH4 concentrations during the past 160 000 years. (derived from ice cores and the U.S. National Oceanic and Atmospheric Administration's Climate Monitoring and Diagnostic Laboratory Program [after Boden et al. 1990:137])
How do we know this?

Monitoring stations at many sites around the world measure concentrations of these gases. This information has been compiled and trends have been analyzed by organizations such as the U.S. Carbon Dioxide Information Analysis Centre (Boden et al. 1990).

What are the reasons for these changes in the atmosphere?

Most of the reasons for these changes are related to human activities. For example, the primary human-related sources of carbon dioxide are fossil fuel combustion, forest fires, deforestation, changing land use (conversion of forested land to agricultural land), and cement production. These sources add an estimated 6.0 billion tonnes of carbon to the atmosphere each year. This rate is more than ten times the rate at the turn of the century (Hengeveld 1991).

Sources of methane emissions include wetlands, rice paddies, digestive processes of certain insects and ruminant (cud-chewing) animals, fossil fuels, biomass burning, and landfills (Boden et al. 1990).

How does deforestation contribute to the increase in atmospheric carbon dioxide?
(Learning Objective A-2.7)

Deforestation, the massive cutting of tropical and temperate forests, changes the atmosphere in at least two main ways. The conversion of large areas of forest into agricultural land may have released more than 100 billion tonnes of carbon into the air over the past century (Hengeveld 1991:26).

Secondly, forests use up carbon dioxide through their photosynthetic process. A decrease in forest lands results in a decreased ability to use carbon dioxide. This can lead to more carbon dioxide remaining in the air.

What are the connections of these gases with other environmental problems?
(e.g., acid rain, upper atmospheric ozone thinning)
(Learning Objective A-2.8)

Nitrous oxides are converted into acids that form acid precipitation. CFCs are implicated in upper atmosphere ozone thinning, as well as being powerful greenhouse gases.

Discuss the carbon budget.
(Learning Objective A-2.6)

The carbon budget is the balance of the exchanges, including both incomes and losses, of carbon between the carbon reservoirs or within one specific loop of the carbon cycle (Figure 3). One specific loop may be between the atmosphere and the biosphere.

Figure 3 Global carbon cycle and carbon storage areas. (All values are in billions of tonnes of carbon [after Hengeveld 1991:26]; data source Watson et al. 1990)

An examination of the carbon budget can provide information about whether the area is functioning as a source or a sink (storage area) for carbon dioxide. The four carbon reservoirs of the Earth are the atmosphere, the land biosphere, oceans, and sediments (includes fossil fuels) (Millemann 1988).

Explain the Earth's radiation budget.
(Learning Objective A-2.2)

The Earth's radiation budget is a description of the difference between the incoming radiation from the sun and the outgoing heat radiation (Figure 4). About half of the incoming solar radiation is absorbed by the Earth's surface. Of the other half, about 31% is reflected back to space by aerosols, clouds and the Earth's surface and about 19% is absorbed by ozone and aerosols (a suspension of fine particles) (Hengeveld 1991).

The Earth's surface and lower atmosphere are heated by the sun's rays and in turn release this energy in the form of heat energy. The two major obstacles encountered by this outgoing energy are absorbing gases (the so-called "greenhouse" gases) and clouds.

Figure 4 Energy flow in the global climate system. (after Hengeveld 1991:14; adapted from MacCracken and Luther 1985)

What is the "greenhouse effect" of the atmosphere?
(Learning Objective A-2.1, A-2.2, and A-2.5)

The "greenhouse effect" is a popular term used to describe the roles of water vapour, carbon dioxide, and other trace gases in keeping the Earth's surface warmer than it would be otherwise (Figure 5). These "radiatively active" gases are relatively transparent to incoming shortwave radiation, but are able to absorb outgoing long wave radiation (e.g., heat). This long wave radiation, which would otherwise escape to space, is absorbed by these gases within the lower levels of the atmosphere. The reradiation of some of the energy back to the surface maintains surface temperatures higher than they would be if the gases were absent. There is concern that increasing concentrations of greenhouse gases (including carbon dioxide, methane, and chlorofluorocarbons) may enhance the greenhouse effect and cause global warming. (Millemann 1988).

The fact that the atmosphere acquires most of its energy from the Earth's surface rather than directly from the sun's rays is very important to the understanding of weather and climate.

The analogy to a greenhouse is imperfect, however, as the garden variety of a greenhouse building provides a partial analogy. The glass in the roof and sides of the greenhouse, like the atmosphere, is relatively transparent to solar energy, but relatively opaque to reradiated heat energy and heat is trapped in the greenhouse. A greenhouse attains higher temperatures because the glass restricts the vertical motion that usually occurs when air is heated. A similar heating occurs in a parked car on a sunny day.

Figure 5 A simplified diagram illustrating the greenhouse effect. (after Intergovernmental Panel on Climate Change 1990:xiv)

What are some of the more important greenhouse gases?
(Learning Objective A-2.3)

Among the most important greenhouse gases are water vapour (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ozone (O3), and halocarbons (e.g., chlorofluorocarbons (CFCs)).

What is global warming?

Global warming and global cooling are the warming and cooling trends undergone by the Earth throughout its history. The term "global warming" has been popularized to include many aspects of the global warming problem (Environment Canada 1993:2). This encompasses the potential future climatic variations that may result from the enhanced greenhouse effect.

What are some evidences for the greenhouse effect?
(Learning Objective A-2.5)

The greenhouse effect is one of the oldest and best established of the atmospheric theories. The greenhouse effect is not disputed (Schneider 1989). Numerous laboratory and satellite measurements as well as analyses support the theory.

The reasons for the difference among the average temperatures of Venus, Mars and Earth is primarily a result of the gaseous compositions of the planets and the greenhouse effect. This results in a Martian deep freeze, a Venusian oven and a habitable Earth. This is called the planetary Goldilocks Phenomenon (Schneider 1989).

What would the Earth be like without the greenhouse effect?

The Earth's average temperature would be about 32°C lower than it is now and life as we know it could not exist (Schneider 1989; Intergovernmental Panel on Climate Change 1990).

What are some evidences of the greenhouse effect links with climate?
(Learning Objective A-2.5)

One type of direct evidence originates in the analysis of bubbles of air trapped in the Antarctic ice sheet. Results showed that carbon dioxide and methane levels in the ancient atmosphere varied in step with each other, and more importantly, with the average local temperatures (Figure 6). The average temperature is determined from the ratio between hydrogen isotopes in the water molecules of the ice. It is not clear whether these trace gas variations caused the climatic changes or vice versa, but the relationship of atmospheric chemistry and climate is important (Schneider 1989).

Figure 6 Analysis of air trapped in Antarctic ice cores shows that methane and carbon dioxide concentrations were closely correlated with the local temperature over the last 160 000 years. Present day concentrations of carbon dioxide are indicated. (after Intergovernmental Panel on Climate Change 1990:xv)
Is the greenhouse effect controversial?
(Learning Objective A-2.4)

The controversy is not in regard to the greenhouse effect - it is one of the oldest and best of the atmospheric science theories. Part of the controversy and debate also results from improper use of scientific terms. For example, the "greenhouse effect" is often improperly used to mean possible future global warming (Palmer 1993). Close attention should be paid to the distinction between the terms (Appendix C - Climatic Change Glossary, page 49). The controversy is about:

• how much global warming will occur and what other climatic changes will result from the increase in the greenhouse effect?
• how fast this will occur;
• how the warming translates into changes in regional and local climate and weather; and
• the effects of these changes.

What is perhaps even more controversial is what to do about the threat of future global warming, that is, what our responses should be. These are controversial because they include value judgements and behavioral changes and they have political and planning implications.

What should we believe?
(Learning Objective A-2.4)

In trying to decide what to believe about controversial issues, it is important to rely on scientific articles that are reviewed by other scientists and on good quality data. It is important to be aware of the assumptions, limitations and uncertainties of the work, as well as conflicts of interest.

Table of Contents

Past, Present and Future Global and Regional Climates

Past Changes - A Brief Overview

Purpose: to show that climates have changed in the past and should be expected to change in the future.
 

How has the global climate changed in the past?

An analysis of surface temperature data since the middle of the last century shows that both hemispheres experienced a general warming from the late 1800s until about 1940 and a cooling trend until the mid 1960s (Figure 7). Since then, the globe as a whole appears to have warmed with a global temperature increase of about 0.3 to 0.6°C (Intergovernmental Panel on Climate Change 1992).

Figure 7 Combined land, air and sea surface temperature anomalies for the globe, 1861-1991 relative to 1951-1980. (after Intergovernmental Panel on Climate Change 1990:147c)

Why should we be concerned about changes of a few degrees in average temperatures?

One half of a degree may seem small, but the average global temperature difference between an ice age and a non-ice age is only about 5 to 6°C. With increases of only more than 1°C global temperatures would result in temperatures that the Earth has not experienced for at least the last 160 000 years (Gullett and Skinner 1992).

Ecosystems are sensitive to small changes in average temperatures. The average annual temperature of the aspen grassland subregion is only about 2°C higher than that of the predominantly forest subregion in western interior Canada (Singh and Wheaton 1991). Therefore, they may be subject to considerable changes with global warming. The student activity on ecological climates provides more detail (Appendix A - Suggested Student Activities, page 37).

Should climate be assumed to be constant?

No - climate has changed in the past, is changing now and will continue to change into the future. This is even more probable with the increase of the greenhouse effect. Humans have changed the Earth's atmosphere and may have already changed the Earth's climate.
What is the present climatic variability and
how does it relate to climatic change projections?

The size of the past global warming is broadly consistent with the projections of climate models, but it is also of the same size as natural climate variability. The observed increase could be largely a result of natural variability, or this variability and other factors could have offset a still larger human-related greenhouse warming (Intergovernmental Panel on Climate Change 1992).

How has the climate of Canada changed in the past?

Canada has warmed by a statistically significant 1.1°C over the 1895 to 1991 period of record. Three distinct phases can be distinguished: a warming from the 1890s to the 1940s; a cooling from the 1940s to the 1970s; and a resumption of the warming from the late 1970s onward. On a regional basis temperature changes range from a moderate cooling of 0.6°C around Baffin and Ellesmere Islands in the far north to a substantial warming of 1.7°C in the Mackenzie District. The warming in Canada over the last hundred years was largest in a broad corridor centred over agricultural Saskatchewan running northwestward through the Mackenzie District (Gullett and Skinner 1992).

"The warming that has been observed in Canada over the past century is unquestionably real and significant, though its intensity has varied from decade to decade and from region to region." (Gullett and Skinner 1992:4).

How has the Canadian prairie climate changed in the past?

The climate of the prairie region has shown a gradual warming between the 1890s and the 1940s, a cooling between the 1940s and 1970s, and a resumption of warming from the 1970s into the 1990s (Figure 8). The temperature change for the region is a statistically significant 0.9°C over the century (Gullett and Skinner 1992:21).
Figure 8 Canadian prairies temperature trend. (after Gullett and Skinner 1992)
Who were some of the scientists and agencies who explored these changes?

The most recent assessment of changes in Canada's temperature climate was led by D.W. Gullett and W.R. Skinner of the Canadian Climate Centre, Atmospheric Environment Service, Environment Canada, Downsview, Ontario. They analyzed changes in average annual temperature between 1895 and 1991 for 131 stations across Canada to determine national and regional temperature trends (Gullett and Skinner 1992).

Many other Canadian scientists have worked and are working on the subject of climatic change. Canadians have contributed to the first "Scientific Assessment of Climate Change" (Intergovernmental Panel on Climate Change 1990). "That report was a comprehensive statement of the state of scientific knowledge concerning climate change and mankind's role therein, and resulted from almost two years' work by 170 scientists worldwide. A further 200 scientists were involved in its peer review." The panel (Intergovernmental Panel on Climate Change) was jointly established by the World Meteorological Organization and the United Nations Environment Programme in 1988.

Possible Future Changes (Learning Objective A-2.9)

What are the causes of climatic change?

Other factors that affect climate, apart from the greenhouse gases, include changes in solar energy (related to changes in the sun's output and changes in the Earth's orbit), changes in atmospheric aerosols (related to pollution or volcanic activity, for examples), and changes in albedo (reflectivity) of the Earth's surface (because of deforestation, desertification, for examples) (Intergovernmental Panel on Climate Change 1990).

How are past and future climates modelled?

We do not have a twin Earth that we can pollute and run field experiments on. So much of the research to understand how an enhanced greenhouse effect will change climate is done by using mathematical models of the processes within the global climate system. The models used are called General Circulation Models. They are based on fundamental laws of physics: conservation of mass, momentum, and energy (Figure 9).

How well are climates modelled?

The simulations of past climate using the General Circulation Models generally agree with the observed trends over time and area. The models do a much better job at simulating climates over large areas and have difficulty with the simulation of smaller areas such as southern Saskatchewan. Also, temperature is modelled with much greater confidence than precipitation.

Figure 9 Schematic description of the structure and processes of general circulation models. (after Bolin et al. 1986:220)

What are key uncertainties and further work required?
(Learning Objective A-2.4)

The key uncertainties result from an inadequate understanding of:

• sources and sinks of greenhouse gases and aerosols;
• clouds and other elements of the water cycle;
• oceans (their influence on the timing and pattern of climate change through their energy storage capacity and changes in circulation);
• polar ice sheets;
• land surface processes and feedbacks, including water and vegetation related processes.

(Intergovernmental Panel on Climate Change 1992)

What are some possible future global climates?

For global temperatures, the new simulations generally confirm the older estimates of future warming at rates of 0.3°C per decade (range of 0.2 to 0.5°C) over the next century. These estimates do not include the effects of sulphates and ozone depletion (Intergovernmental Panel on Climate Change 1992).

Other features of the results of General Circulation Model runs for doubling atmospheric carbon dioxide, that is, characteristics of future possible global climates, include:

• enhanced warming in higher latitudes in late autumn and winter;
• enhanced precipitation in high latitudes and the tropics throughout the year, and in middle-latitudes in winter; and
• enhanced large area drying of the Earth's surface in northern middle-latitudes during the northern summer.

(Intergovernmental Panel on Climate Change 1990)

What is the confidence in the projections of climatic change likely
to occur as a result of a doubling of carbon dioxide?
(Learning Objective A-2.4)

Confidence in projections for a global basis are high for temperature, sea level, and precipitation and low for solar radiation. Confidence in regional projections is much less: medium for temperature and soil moisture and low for precipitation, evaporation, transpiration, and water runoff (Schneider and Rosenberg 1989).

What are some possible future prairie climates?

Several possible future prairie climates under global warming are described in Wheaton, Wittrock and Williams (1992). Results from the Canadian Climate Centre's General Circulation Model for the province (for a doubling of atmospheric carbon dioxide) are:

• largest temperature increases are expected for the winter for most of the province, with increases generally larger in the south (Figure 10);
• temperature increases expected for summer are not as large (Figure 11), but are still significant at about 4 to 6°C. This means that the chance of having more summers similar to that of 1988 increases. Do you remember the heat waves and intense and large area droughts of 1988? The average temperature at Saskatoon in June of 1988 was 5.7°C greater than normal. Such high average temperatures resulted in record high daily temperatures of over 40°C for several places in the prairies. The effects of the drought were numerous and often severe (Wheaton and Arthur 1989);
• precipitation increases are largest for much of the province during late spring and winter (Figure 12);
• precipitation decreases are projected for large portions of the province during the summer (Figure 13).

Figure 10 Winter temperature change (°C) scenario for the Canadian Prairie Provinces from the Canadian Climate Centre's (CCC) 1990 second generation General Circulation Model (GCMII) results for a doubling of carbon dioxide (2xCO2). (Wheaton et al. 1992:20; data source Environment Canada)

Figure 11 Summer temperature change (°C) scenario for the Canadian Prairie Provinces from the CCC90 General Circulation Model results for 2xCO2. (Wheaton et al. 1992:22; data source Environment Canada)

Figure 12 Winter precipitation change (%) scenario for the Canadian Prairie Provinces from the CCC90 General Circulation Model results for 2xCO2. (Wheaton et al. 1992:26; data source Environment Canada)

Figure 13 Summer precipitation change (%) scenario for the Canadian Prairie Provinces from the CCC90 General Circulation Model results for 2xCO2. (Wheaton et al. 1992:28; data source Environment Canada)
What will be the effect of future climate change on ecosystems?

The nature of ecosystems is strongly affected by climate. Ecosystems will respond to local changes in temperature, precipitation, soil moisture and other elements. Species respond differently to climatic change; some will increase in abundance and/or range and others will decrease. Ecosystems will therefore change in structure and composition. Some species may be prone to local and even global extinction, and other species may thrive. The rate of climatic change will be especially important to ecosystem response (Intergovernmental Panel on Climate Change 1992).

Past long-term climatic changes have caused displacement of the ecosystems. Future climates matched to ecosystems could move hundreds of kilometres northward with climatic change (Singh and Wheaton 1991). The first student activity explores this further (Appendix A -Suggested Student Activities, page 37).

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Student Activities

Several types of student activities are suggested here and details are provided in Appendix A - Suggested Student Activities (page 37). A set of different activities is included to give the instructors and students flexibility to choose the most appropriate activities. The topic areas are:

• use of global warming and education software;
• the activity on shifting climates of ecosystems with global warming; and
• display and demonstration of environmental monitoring equipment.

The activity on shifting ecological climates was tested during the Rosetown workshop and by the Grade 10 students in Langham. Most of the environmental equipment listed in Appendix A was displayed and demonstrated in both workshops.

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What are the Possible Effects of a Changed Climate on Canada and the Canadian Prairies?

The answers to questions in this section are left up to the teachers and students, with the exception of the third question. Considerable uncertainty lies in the assessment of the regional effects of a changing climate and much more work is needed in this area. References for research to develop this section include Wheaton, Wittrock and Williams (1992); Williams et al. (1988); Arthur (1988); and Hengeveld (1991). Analogies of past drought years (e.g., Wheaton and Arthur 1989) or warmer areas could also be used as literature reviews or in terms of interviews to examine effects of and responses to climate.

A map of possible effects on the regions of Canada is included as a basis for discussion and further analysis (Figure 14).

Figure 14 Possible effects of climatic change on Canada.

A set of possible questions to address include:

What parts of the environment and what resource sectors (e.g., agriculture, forestry, energy) are affected by climate and therefore by climatic change?

How are the environment and resource sectors (agriculture, forestry, mining, etc.) affected by climatic change?

How might agriculture in the Canadian prairies be affected by global warming? (Learning Objective A-2.10).

It is very difficult to estimate the possible effects of global warming on agriculture because of the complexities, uncertainties, and early stage of the research work. The estimations of effects of future warming are based on knowledge of the past relationships of climate and agriculture, including the effects of wet and dry periods.

Future climatic changes will affect many aspects of the agricultural ecosystem including: soil resources; crop growth and yield; crop types grown; livestock production; insects and diseases; and water resources. Warming will tend to increase wind erosion of soil which may be offset by increased precipitation and improved vegetation cover and management. The climate may become less appropriate for currently grown crops but more suitable for a range of other crops. Warming may expand the winter survival ranges of insects and diseases northward and from neighbouring areas.

A complex combination of both positive and negative effects should be expected depending upon the nature of the climate, its extremes (e.g., drought) and the producer's capability to adapt to a changing climate.

How are you affected by changing climates?

How are your activities affected by changing climates?

How might human health be affected by climatic change?

How is the economy affected by a changing climate and its effects?

How are political situations affected by changing climates?

What are some direct effects of climate change (e.g., effects on health or agriculture due to heat waves)?

What are some indirect effects of climate change (e.g., effects on human health or agriculture due to decreasing water supply)?

How can society and the economy be affected by climate and climate change?

How can individuals and society prepare for and adapt to climatic change? (Refer to the next section for examples.)

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What Can We Do? (Learning Objectives A-2.11 and 12)

What can the public, professionals (scientists and engineers), decision-makers, and policy developers do to help deal with the problem? The framework developed to guide Canada's action on global warming is called the "National Action Strategy on Global Warming" (Government of Canada 1991). "This strategy guides federal, provincial and municipal governments, all sectors of the Canadian economy and all Canadians in identifying their own actions to work towards national goals." The three basic goals of this plan are:

• limiting and reducing the emissions of greenhouse gases to 1990 levels by the year 2 000 AD;

• anticipating and preparing for potential climatic changes which Canada may experience as a result of global warming; and

• improving scientific understanding and predictive capabilities with respect to climate change.

The following actions address at least one or more of these main areas. For example, using public transportation leads to less fossil fuel burned and less CO2 being emitted into the atmosphere. Reforestation and conserving soil are actions that tend to store CO2 and reduce amounts in the atmosphere.

Public

• Use public transportation and more fuel efficient or cleaner fuel vehicles. This will reduce emissions of greenhouse gases.

• Conserve electricity and use it efficiently.

• Use alternative energy sources - person power (bicycles), solar panels, wind energy, geothermal energy, etc.

• Do not use products with chlorofluorocarbons (CFCs) or that use CFCs in their production. CFCs are powerful greenhouse gases and are also implicated in the depletion of the ozone layer.

• Use the four "R"s - reduce, reuse, recycle and recover. For example, reducing garbage would help deal with a greenhouse gas emission problem. Continued growth of garbage contributes to the growth of landfills. Landfills are a large source of methane, a powerful greenhouse gas.

• Conserve soil - soil erosion leads to loss of carbon from the soil.

• Plant trees and preserve forests and grasslands.

• Keep informed - improve your knowledge of this issue and other related aspects.

• Become an environmental scientist.

• Become an environmentally aware decision- or policy-maker.

• Inform politicians of your concerns and let them know what you want done about them.

• Find out more about climatic change and variability.

• Improve our preparations for and adaptations to climatic change and variability.

Scientists and Engineers

• Monitor the environment (atmosphere, land, vegetation, water - all parts of the ecosystem) and evaluate trends.

• Improve our knowledge of the effects of climate on the environment and on resource sectors and of adaptation strategies.

• Improve our understanding of the environment and of the way humans interact with it.

• Improve our capability to prepare for and adapt to climatic change.

• Develop alternatives to CFCs and develop alternative energy sources and improve conservation methods.

• Improve electricity demand management.

• Support policies (such as the Montreal Protocol, Climate Change Convention) to reduce net emissions of the greenhouse gases.

Government and Non-Government Agencies (Learning Objective A-2.11)

• Stimulate research on climatic change, climatic change impact and adaptation research.

• Support environmental conservation measures.

The following are from Rosenzweig and Ropes (1990):

• Increase the amount of energy derived from sources that emit less carbon dioxide. For example, natural gas emits less CO2 than coal. Non-fossil energy sources include hydro, geothermal, wind, solar, and nuclear.

• Make motor vehicles more energy-efficient. Increase the use of public transit and car pools.

• Use electronic communication - move information, not people.

• Establish higher standards for the efficiency of major electrical appliances.

• Minimize waste of energy caused by inefficient heating, lighting and air- conditioning systems.

• Reduce destruction of forests and the consequent burning of timber and brush.

• Encourage reforestation and afforestation.

• Spread the use of advanced processes for the production of basic materials and disposal of waste materials.

• Prohibit, or severely reduce, the use of CFCs (an international agreement known as the Montreal Protocol has already begun to restrict CFCs).

• Increase research on ways to minimize greenhouse gas effects.

• Maximize public awareness of the problem.

The following are examples of ethical action recommended by the Calgary Institute for the Humanities (1992):

• Phase out synthetic gases that increase the greenhouse effect.

• Adopt all energy conservation measures that are economically attractive.

• Provide economic and other incentives for individuals to take into account the adverse impacts of their decisions and lifestyles on the environment.

• Work together with developing countries to adopt suitable energy-efficient technologies.

• Develop international institutions to provide compensation, where appropriate, to those who suffer harm as a result of human-induced global warming.

Several Saskatchewan oriented and general recommendations are in Wheaton, Wittrock and Williams (1992). It was written by authors with experience in Saskatchewan issues and considerable information was derived from Saskatchewan expert judgement.

Although these works contain most of the major actions regarding this issue, many more are available (e.g., Hogan 1992) and many more are being developed and implemented. This section is intended for material to facilitate discussion and is not intended to be a complete list of actions (if that is even possible).

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Career Opportunities - Examples

Another type of action related to global change is to develop a career in this area. What types of career opportunities are there in this area of global and regional environmental change? Some examples of job opportunities are provided in this section (Figure 15). This appears to be an area of expanding career opportunities.

Figure 15 Samples of career opportunities in the climatic change field.

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Conclusion

Global warming could continue indefinitely unless emissions are reduced to the capacity of sinks to absorb them (Cooper 1989). The projections of climatic change, if realized, will amount to a revolutionary change in world climate, at a rate of change never before experienced in the history of civilization. Dr. K. Hare, one of Canada's foremost climatologists, is referring to global warming when he says, "I have no doubt that we are discussing the central environmental problem of our times." (Hare 1988:63). There is relatively high probability that the projections of unprecedented climatic change into the next century will be realized; waiting for that extra degree of certainty is not without its risks (Schneider 1989).

Much scientific evidence supports the conclusion that the world's climate is at considerable risk of changing because of human-related increases in the greenhouse gases. We cannot ignore this possibility. We are responsible for the threat of global warming and we are also responsible for dealing with it.

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Student Program Evaluation

J. Duerksen

This evaluation will be used to modify the overall program that you have just completed. All of your comments will be carefully and completely examined to help improve and develop the setup, timing, materials, delivery, and focus of the day. Your comments are valuable to both the presenter as well as the organizers. Please take your time and comment on EACH section, knowing that what you say will have an impact.

A. OVERVIEW

1. What do you feel were the main points of the day?

2. For the entire day, which section/information do you feel will be the greatest use to you in the future?

3. If you could extend ONE part of the day, which section or topic would you choose?

4. If you could omit one section, which one would you omit?

5. What do you foresee as a possible activity that might have some impact for your town or city, or the town (city) and area, in light of your new knowledge?

B. SETUP

1. Is the classroom a suitable location? Suggest alternatives.

2. What effect did the cameras, etc., have on your questions/responses during the day?

3. Are there any questions you may have asked if the setup would have been different? Please list.

C. TIMING

1. Please comment, by using a rating scale of 1 to 10, with 10 being the ideal in regards to the length of time spent on each of the following. Indicate more time with a "+" and less time using "-" in front of your numbers.
a) introduction
b) overview
c) slides
d) changes in the Earth's greenhouse
e) past and present climates
f) future climates
g) student exercise
h) implications
i) careers
j) evaluation

D. FILL IN THE BLANKS using any section of the day in regards to the presentation of information.
too fast
too slow
more info. needed
too much info.
not clear
very clear
most interesting
most boring

E. STUDENT ACTIVITY - circle and comment please
1. time spent - too long, too short
2. level of activity - too low, appropriate, too high
3. results analysis - clear, unclear
4. discussion - too long, about right, too short

F. FOCUS

1. Was the topic one that is suitable for you?

2. What other topics would interest or be of use to you?

G. COMMENTS FOR THE SCIENTIST/ENGINEER

H. COMMENTS FOR THE ORGANIZERS

* THANK YOU FOR A GREAT DAY!

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Climatic Change and the Greenhouse Effect

REFERENCES AND FURTHER READING

Compiled by E.E. Wheaton

Most of these references are readily available through local libraries, from the Government of Canada, or from the Saskatchewan Research Council Information Centre. Key general references for an overview of the problem include: Government of Canada (1991), Intergovernmental Panel on Climate Change (1990), Hengeveld (1991), Hogan (1992), Wheaton (1989), and Wheaton et al. (1992).

* Suggested key references for supplementing the instructor's outline.

American Meteorological Society, 1989. Second International Conference on School and Popular Meteorological and Oceanographic Education. July 12-16, 1989. Crystal City, Virginia. American Meteorological Society, Boston, Massachussets.

Arthur, L.M., 1988. The Implications of Climate Change for Agriculture in the Prairie Provinces. Climate Change Digest. CCD 88-1. Environment Canada, Downsview, Ontario.

Arthur, L.M., V.J. Fields and F. Abizadeh, 1987. Socio-Economic Assessment of the Implication of Climate Change for Agriculture in the Prairie Provinces: Phase III. Report presented to the Atmospheric Environment Service. Department of Agricultural Economics, University of Manitoba, Winnipeg, Manitoba (March).

Boden, T.A., P. Kanciruk and M.P. Farrell, 1990. Trends '90 - A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge, Tennessee.

Brightwell, H., 1990. Parliamentary Forum on Global Climate Change. Queen's Printer, House of Commons, Ottawa, Ontario.

Bruce, J.P., 1991. Myths and Realities of Global Climate Change. Ecodecision 1:89-92.

Calgary Institute for the Humanities, 1992. Ethics and Climate Change. Climlist October 23, 1992. Calgary Institute for the Humanities, University of Calgary, Calgary, Alberta.

* Canadian Climate Program Board, 1991. Climate Change and Canadian Impacts: The Scientific Perspective. Climate Change Digest CCD 91-01. Environment Canada, Ottawa, Ontario.

Cohen, S., E. Wheaton and J. Masterton, 1992. Impacts of Climatic Change Scenarios in the Prairie Provinces: A Case Study from Canada. Conference Proceedings, Impacts of Climatic Variations and Sustainable Development in Semi-arid Regions, January 27 to February 1, 1992, a contribution to UNCED, Fortaleza, Ceara, Brazil.

Cooper, C.L., 1989. Epilogue. In: Rosenberg et al., (Eds.).

Ecoregions Working Group, 1989. Ecoclimatic Regions of Canada, First Approximation. Ecoregions Working Group of the Canada Committee on Ecological Land Classification. Ecological land Classification Series, No. 23. Sustainable Development Branch, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario.

* Environment Canada, 1993. A Matter of Degrees: A Primer on Global Warming. Office of Environmental Citizenship, Atmospheric Environment Service, Ottawa, Ontario.

Environment Canada, 1987. Climatic Atlas Canada, Map Series 1, Temperature and Degree-Days. Atmospheric Environment Service, Environment Canada, Downsview, Ontario.

Environment Canada, 1988. The Changing Atmosphere: Implications for Global Security. Environment Canada, Ottawa, Ontario.

Environment Canada, 1982-1984. Canadian Climate Normals, 1951-1980. Environment Canada, Downsview, Ontario.

Environment Canada, 1984-1989. Climatic Atlas Canada, Seven Map Series. Environment Canada, Downsview, Ontario.

Environment Canada, 1987. Temperature and Degree-Days, Climatic Atlas Canada, Map Series 1. Atmospheric Environment Service, Environment Canada, Downsview, Ontario.

Flavin, C., 1989. Slowing Global Warming: A Worldwide Strategy. Worldwatch Paper 91. Worldwatch Institute, Washington, D.C.

* Government of Canada, 1991. Canada and Global Warming, Meeting the Challenge. Government of Canada, Ottawa, Ontario.

* Gullet, D.W. and W.R. Skinner, 1992. The State of Canada's Climate: Temperature Change in Canada 1895-1991. A State of the Environment Report No. 92-2. Environment Canada, Downsview, Ontario.

Hare, F.K., 1988. Jumping the Greenhouse Gun? Nature 334:646, August 25, 1988.

Hare, F.K. and M.K. Thomas, 1979. Climate Canada. 2nd Edition. J. Wiley and Sons Canada Ltd., Rexdale, Ontario.

Harvey, L.D., 1991. Climate Change: Warming to the Challenge. Chapter 22 in: The State of Canada's Environment. Government of Canada, Ottawa, Ontario, pp 22.1-22.8.

* Hengeveld, H., 1991. Understanding Atmospheric Change - A Survey of the Background Science and Implications of Climate Change and Ozone Depletion. A State of the Environment Report. SOE Report 91-2. Environment Canada, Downsview, Ontario.

IUCN/UNEP/WWF (The World Conservation Union/ United Nations Environment Programme/ World Wide Fund for Nature), 1991. Caring for the Earth - A Strategy for Sustainable Living. Gland, Switzerland.

Intergovernmental Panel on Climate Change (IPCC), 1990. Climate Change: The IPCC Scientific Assessment. Report prepared by Working Group 1: J.T. Houghton, G.J. Jenkins and J.J. Ephraums (Eds.). Cambridge University Press, Cambridge, United Kingdom.

Intergovernmental Panel on Climatic Change (IPCC), 1992. Climate Change 1992, The Supplementary Report to the IPCC Scientific Assessment. J.T. Houghton, B.A. Callander and S.K. Varney (Eds.). Cambridge University Press, Cambridge, United Kingdom, 205 pp.

Lutgens, F.K. and E.J. Tarbuck, 1992. The Atmosphere: An Introduction to Meteorology. 5th Edition, Prentice Hall, Englewood Cliffs, New Jersey.

MacCracken, M.C. and F.M. Luther (Eds.), 1985. Projecting the Effects of Atmospheric Carbon Dioxide. Department of Energy, Washington, D.C.

Millemann, R.E., 1988. A Glossary for Carbon Dioxide and Climate. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory for the U.S. Department of Energy, Oak Ridge, Tennessee.

Nichols, H., 1967. The Post-Glacial History of Vegetation and Climate at Ennadai Lake, Keewatin, and Lynn Lake, Manitoba. Eiszeitalter und Gegenwart 18:176-197.

Nichols, H., 1976. Historical Aspects of the Northern Canadian Treeline. Arctic 29:38-47.

Palmer, T.N., 1993. A Nonlinear Dynamical Perspective on Climate Change. Weather 48(10):314-326.

Parry, M.L., T.R. Carter, and N.T. Konijn (Eds.), 1988. The Impact of Climatic Variations on Agriculture, Vol.1: Assessments in Cool Temperate and Cold Regions. Kluwer Academic Publisher Dordrecht, The Netherlands.

Phillips, D., 1990. The Climates of Canada. Minister of Supply and Services Canada, Ottawa, Ontario.

* Resources Futures International, 1993. Global Change and Canadians. Canadian Global Change Program, Royal Society of Canada, Ottawa, Ontario.

Ritchie, J.C., 1983. The Paleoecology of the Central and Northern Parts of Glacine Lake Agassiz Basin. In: J.T. Teller and L. Clayton (Eds.), Glacial Lake Agassiz Geological Association of Canada, Ottawa. Special Paper, pp. 156-170.

Ritchie, J.C. and F.K. Hare, 1971. Late-Quaternary Vegetation and Climate near the Arctic Tree Line of Northwestern North America. Quaternary Research 1:331-342.

Rosenberg, N.J., W.E. Easterling III, P.R. Crosson, and J. Darmstadter (Eds.), 1989. Greenhouse Warming: Abatement and Adaptation. Proceedings of a workshop, June 14 to 15, 1988. Resources for the Future, Washington, D.C.

Rosenzweig, C. and G.H. Ropes, 1990. Hothouse Planet. EME Corporation, Danbury, Connecticut.

Rowe, J.S., 1972. Forest Regions of Canada. Canadian Forestry Service Publication No. 1300. Forestry Canada, Ottawa, Ontario. 172 pp + map.

Saskatchewan Education, 1991. Science 10, A Curriculum Guide for the Secondary Level. Saskatchewan Education, Regina, Saskatchewan.

* Schneider, S., 1989. The Changing Climate. Scientific American 261(3):70-79.

Schneider, S.H. and N.J. Rosenberg, 1989. The Greenhouse Effect: Its Causes, Possible Impacts, and Associated Uncertainties. In: Rosenberg et al. (Eds.).

Singh, T. and E.E. Wheaton, 1991. Boreal Forest Sensitivity to Global Warming: Implications for Forest Management in Western Interior Canada. Forestry Chronicle 67(4):342-348.

Smit, B., 1989. Climate Warming and Canada's Comparative Position in Agriculture. Climatic Change Digest. CCD 89-01. Minister of Supply and Services, Ottawa, Ontario.

* Standing Committee on the Environment (SCOE), 1990. No Time to Lose: The Challenge of Global Warming. Part II of "Our Changing Atmosphere" Series. House of Commons Canada, Queens Printer, Ottawa, Ontario.

Strahler, A.N. and A.H. Strahler, 1978. Modern Physical Geography. J. Wiley and Sons, New York, N.Y.

Watson, R.T., H. Rodhe, H. Oeschger, and U. Siegenthaler, 1990. Greenhouse Gases and Aerosols. In: Intergovernmental Panel on Climate Change (IPCC), 1990.

Webster's. Webster's Ninth New Collegiate Dictionary. T. Allen & Son Ltd., Markham, Ontario.

* Wheaton, E.E., 1989. Global Warming - Implications of Climatic Uncertainty for the Canadian Prairies. Saskatchewan Research Council (SRC) Publication No. E-2000-37-D-89. SRC, Saskatoon, Saskatchewan.

* Wheaton, E.E., 1991. Global Warming - Some Implications of Climatic Uncertainty for the Canadian Prairies. Canadian Prairie and Northern Section of the Air and Waste Management Association Meeting, Regina, Saskatchewan, December 14, 1989. Saskatchewan Research Council (SRC), Saskatoon, Saskatchewan.

* Wheaton, E.E., 1991. Global Warming: How could it Change Saskatchewan? University of the People Speaker Series, Saskatoon, Saskatchewan. Saskatchewan Research Council (SRC), Saskatoon, Saskatchewan.

* Wheaton, E.E. and L.M. Arthur (Eds.), 1989. Environmental and Economic Impacts of the 1988 Drought - with Emphasis on Saskatchewan and Manitoba. Volume 1. Prepared for the 1988 Drought Steering Committee. Saskatchewan Research Council (SRC) Publication No. E-2330-4-E-89. SRC, Saskatoon, Saskatchewan.

* Wheaton, E.E., and T. Singh, 1989. Exploring the Implications of Climatic Change for the Boreal Forest and Forestry Economics of Western Canada. Climate Change Digest CCD 89-02. Environment Canada, Downsview, Ontario. Saskatchewan Research Council (SRC) Publication No. E-906-61-A-88.

Wheaton, E.E. and J.P. Thorpe, 1989. Changing Climatic Resources for the Western Canadian Boreal Forest. In: MacIver, D., H. Auld, and R. Whitewood (Eds.), Proceedings, 10th Conference on Fires and Forest Meteorology Conference. Ottawa, Ontario. April 17-21, 1989, pp.172-176.

* Wheaton, E.E., V. Wittrock, and G.D.V. Williams. 1992. Saskatchewan in a Warmer World: Preparing for the Future. Saskatchewan Research Council (SRC) Publication No. E-2900-17-E-92, SRC, Saskatoon, Saskatchewan.

Wheaton, E.E., T. Singh, R. Dempster, K.O. Higginbotham, J.P. Thorpe, G.C. van Kooten and J.S. Taylor, 1987. An Exploration and Assessment of the Implications of Climatic Change for the Boreal Forest and Forestry Economics of the Prairie Provinces and Northwest Territories. Saskatchewan Research Council (SRC) Publication No. E-906-36-B-87, Prepared for the Canadian Climate Centre. SRC, Saskatoon, Saskatchewan.

* Williams, G.D.V., R.A. Fautley, K.H. Jones, R.B. Stewart and E.E. Wheaton, 1988. Estimating Effects of Climatic Change on Agriculture in Saskatchewan, Canada. In: Parry et al. (Eds.), pp. 219-379.

World Resources Institute (WRI), 1992. Teacher's Guide to World Resources 1992-93: Comprehensive Coursework on the Global Environment. WRI, Washington, D.C.

Personal Communications

Adams, D., 1993. Teacher, W.W. Brown School, Langham, Saskatchewan.

Aikenhead, G., 1993. Professor, Science Education, College of Education, University of Saskatchewan, Saskatoon, Saskatchewan.

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Suggested Student Activities

E.E. Wheaton

1. SHIFTING ECOCLIMATIC ZONES OF THE PRAIRIE PROVINCES - A STUDENT ACTIVITY

SRC Publication No. E-2900-6-E-93

Introduction

Climate is a primary factor affecting the distribution and character of ecosystems. Climate has changed in the past and continues to change. The climatic change of increasing concern is based on the well documented increase in atmospheric concentrations of the greenhouse gases. The type of global climate change that is thought to occur will have significant effects on climatic resources that affect ecosystems, and therefore on the ecosystems (Singh and Wheaton 1991).

The implications of the enhanced greenhouse effect and climatic change for the ecosystems of western Canada are serious because of the combination of these ecosystems' sensitivity to climate and the fact that the greatest temperature increases are projected for these locations at high latitudes and in a mid-continental position. Considerable changes in precipitation and soil moisture amounts and timing are also projected, but with much less certainty, especially on the regional basis.

Shifts in global ecosystems in the past have been related to climatic changes. Pollen records clearly show that the latitudinal zones of the boreal tree species, for example, were different at different periods in recent history (Nichols 1967, 1976). During the time period when warmer and drier climatic conditions in North America peaked about 6 000 years ago, the summer average temperatures were 2 to 3°C higher than at present (Ritchie 1983). As a result, the northern limit of the boreal forest extended far north of its present boundaries, and grasslands occupied most of the southern portions of the boreal region in western Canada (Ritchie and Hare 1971). The anticipated changes in temperature will exceed this range and rate of change if the enhancement of the greenhouse effect continues.

Growing degree-days (GDD) have been used to simulate the zonation and productivity of ecosystems, such as the boreal forest (e.g., Wheaton et al. 1987). Growing degree-days are selected because of their long history of characterizing the temperature requirements for vegetation, both in Canada and internationally. GDD are indicative of both growing season length and temperature accumulations.

In order for plant growth to proceed, air temperature must exceed a critical value appropriate to the plant species in question. For many members of the grass family, including most commercial cereals grown on the prairies, a base temperature of 5.0°C is used. Each day of the year can be assigned a growing degree-day (GDD) value.

The daily value is calculated by finding the difference between the daily mean temperature and the base temperature (5.0°C).

GDD = (T - 5.0°C)

where T is the daily mean temperature in °C (note that if T is equal to or less than 5.0°C, GDD=0). The GDD values for the year are added to determine an annual value.

Vegetation zonation changes will occur with climatic changes. The boreal and grassland ecosystems have the potential to shift northwards with a change to a warmer climate. The shift in the position of the climate of the ecosystems can be estimated by using the position of the 600 and 1 300 GDD isolines as approximations of the present northern and southern boundaries of the boreal forest (Figure A.1).

Suggestions for the Use of this Activity

The remainder of this activity is an outline to be used as a guide for the students and teachers to complete this process and for discussions as well as presentations and reports. The Glossary (Appendix C, page 49) and References and Further Reading (page 31) in this report provide supplemental supporting information recommended for use with this activity.

This activity is a considerable simplification of reality. Our understanding of ecosystem-climate relationships and future climate changes is inadequate so many assumptions are used. The format used for this activity is the one of the best formats for research articles for publication in scientific journals. It can be used to discuss and to write-up this and other experiments and projects.

Objectives (This section addresses the question "what are we going to do?")

1) Compare the present climate to the patterns of the boreal forest and grassland ecosystems.

2) Construct a possible future climate for the region and compare it to the present ecoclimates.

3) Explore the implications of changing climate for the ecosystems and for human activities.

Data and Methodology (This section deals with the question "how do we do this project?")

The instructor could initiate the students to the methodology by using an overhead of Figure A.1.

1) Compare the positions of the 600 and 1 300 GDD isolines3 of the "present" climate (1951 to 1980) with the current northern and southern positions of the boreal forest and the northern position of the grasslands (Figure A.1).

2) Determine the position and pattern of the 600 and 1 300 GDD isolines for a climatic change scenario by the following steps:

• write the number of GDDs for each grid point4 on Figure A.1 using the information from Table A.1.

• interpolate between the grid points to find the 600 and the 1300 GDD points.

• draw isolines for 600 and 1 300 GDDs. These lines represent the changed position of the boreal forest climate with a warmer climate as based on the Geophysical Fluid Dynamics Laboratory Climate Model for a doubling of atmospheric carbon dioxide.

3) Compare the positions of the 600 and 1 300 GDD isolines of the present climate and of the climatic change scenario by:

• measuring (in kilometres) the smallest and largest shifts of the northern boundary using the map scale at the bottom of the map.

• repeat the above step for the southern boundary.

• produce a table of these ranges of the shift in position of the northern and southern boundaries of the boreal forest climate.

• describe the pattern of these changes using your table and figure.

Results and Discussion (What did we learn? Students could present and discuss results. Keep to the main results as in Figure A.2 and Tables A.2 and A.3.)

Questions to address include:

• how well do the present GDD isolines match the position of the boreal forest and grassland regions? Where do their patterns differ?

• what is the change in position of the northern and southern boundaries?

• what does this mean for the total area of the climate of the boreal forest?

• how fast can the forests move northward with the shifting climate? (Migration occurs by seed dispersion and rootstock sprouting.)

• what does this changing climate mean for the ecosystems? For example, some plants will migrate faster than others and some cannot migrate fast enough.

• what types of new ecosystems may result?

• what effects could the change in ecoclimate have for humans and human activities?

• how do scientists reach consensus on a conclusion that is published and made public?

• how confident are you in your results?

Conclusion and Recommendations

The students are encouraged to develop their own conclusions and recommendations from their research activities.

Future and present changes in climate caused by the increasing greenhouse effect and other factors could have significant effects on the boreal forests of western Canada, and indeed, on the circumpolar boreal forest.

Many uncertainties exist regarding our understanding of climate-ecosystem relationships. Improvements in the tracking of the possible effects of global warming on the boreal forest ecosystem is crucial. Comprehensive resource management strategies should address global warming implications.

STUDENT ACTIVITIES - EXAMPLES OF SOFTWARE

1) Cox, R. and C. Cox, 1992 version. Save the Planet. Cox, Pitkin, Colorado.

This is an interactive display program which contains considerable recent information and data about global environmental issues including the increasing greenhouse effect and global warming. The software includes a global warming model that demonstrates what kind of temperatures today's children will most likely experience in the next 60 years.

This software is available for either IBM compatible computers or the Apple Macintosh. Contact "Save the Planet Software", P.O. Box 45, Pitkin, Colorado 81241 for the material. The cost is $24.95 US.

2) Rosenzweig, C. and G.H. Ropes, 1990. Hothouse Planet. EME Corporation, P.O. Box 2805, Danbury, Connecticut.

"This program enables students to study the Greenhouse Effect - its causes, its potential impact on Earth's climate and sea level, and what can be done to minimize likely adverse outcomes.

Students are able to observe the results of changes in the factors that affect global temperature and sea level, including changes in specific regions and selected cities of North America."

The software is available from EME Corporation, P.O. Box 2805, Danbury, Connecticut 06813-2805.

3. STUDENT ACTIVITIES - A DEBATE

There are several aspects of the increasing greenhouse effect problem that are known and several that are not known, as indicated in the Instructor's Guide. For example, it is clear that atmospheric concentrations of the greenhouse gases are increasing. Also, the greenhouse effect theory is well established.

Several areas that are uncertain or less certain and require further investigation include many aspects of climatic modelling, the effects of climatic change (on agriculture, for example), and adaptation to climatic change (how people can respond to reduce the negative effects).

The purpose of the debate would be to discuss and clarify what is known and not well known, as well as to practice debating skills. Students could search newspapers to find articles which may be a useful starting point.

The clarification of the definition of the various scientific terms is necessary for a useful debate on this subject. Part of the controversy stems from misuse of terms, such as the confusion of "greenhouse effect" and future global warming. The Glossary (Appendix C, page 49) is provided for this purpose.

4. OTHER STUDENT ACTIVITIES

The following are taken from Rosenzweig and Ropes (1990):

1) List manufactured products whose sales would increase as global temperatures increase. Also list those products whose sales would probably decrease as global temperatures rise.

2) Ask a school administrator and/or custodian to describe the problems that flooding in your school would cause.

The following are ideas for investigation which can be expanded upon or changed to be made more or less sophisticated, as needed:

• What is global warming?

• How could global warming affect drought on the prairies?

• Why should we care?

• Investigate and describe some of the positive and negative impacts of drought in the Canadian Prairie Provinces?

• Investigate and describe some ways that people could reduce the negative effects of drought.

• Compare and contrast the possible effects of climatic change in different parts of the world.

• How would climatic warming affect the recreational activities that you enjoy?

• How might climatic change affect wildlife and their habitat?

• Investigate and describe some of the possible effects of climatic change on agriculture in Saskatchewan.

• What can be done?

• How might the negative effects be avoided?

• How might the positive effects be enhanced?

These ideas may be investigated by means of several methods, such as by interviews with experts or people who could be affected, by field experiments, or through literature reviews. The interviews with other students or with experts using some of the above questions could be video taped to be shown to other students, parents, and others (Adams 1993, p. comm.).

5. ENVIRONMENTAL MONITORING EQUIPMENT

The following monitoring equipment can be displayed and demonstrated:

• CO2 sampler (Gastec)

• maximum and minimum thermometers

• precipitation gauges

• acid rain automatic collector

• air sampler equipment

• hand-held wind meter

Instructions for use are included with the equipment or can be obtained from the supplier. Some, such as the precipitation gauges and thermometers, are readily available. Others such as the acid rain automatic collector are only available at the Saskatchewan Research Council.

Another research activity would be to design a comprehensive environmental monitoring program selecting from and perhaps expanding upon the above list.

Environmental monitoring is the scientific foundation to provide information about the changes to our environment. Carefully designed and executed monitoring programs and the assessment of data from these programs are of considerable value to global environmental change work and all of its benefits.

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E.E. Wheaton

As requested by the Saskatchewan School Trustees Association, a module on this topic is included to provide further background information for the development of appropriate responses to global change. The work regarding ethics and global warming is at an early stage and is an essential part in determining and evaluating response actions.

The two main references for this section include a statement from the Calgary Institute for the Humanities, University of Calgary (1992), and a publication entitled "Caring for the Earth - A Strategy for Sustainable Living" published by the World Conservation Union, the United Nations Environment Programme and the World Wide Fund for Nature (IUCN/UNEP/WWF 1991).

A framework for the process of protecting the climate may also be developed by students based on the development of their knowledge of the source and sinks of the greenhouse gases.

The statement put forward by the Calgary Institute for the Humanities for use as a basis in formulating Canada's negotiating strategy at the United Nations Conference on Environment and Development in 1992 is as follows:

"There is an ethical obligation to avoid the negative consequences of human induced global warming as long as this obligation does not affect unacceptably the quality of life of people, especially those whose quality of life is lowest. There is a further obligation to ensure that any negative consequences of warming are allocated equitably among humans and are not imposed unilaterally on some groups by others.

The ethical bases of these obligations are several. One is the requirement to avoid needless suffering by humans and non-humans. Another is the requirement to preserve the natural environment as something valuable to and valued by humans - as a source of good health, economic resources, recreation and beauty. This second requirement is one aspect of a larger responsibility to ensure a decent quality of life for future generations, a responsibility that is central to the concept of sustainable development. Finally, there is a duty to preserve nature as something valuable in itself apart from its usefulness to humans.

The above ethical obligations can be arrived at either by secular analysis or from any of the world religions. All or most of these obligations should be widely accepted in a pluralist society."

This statement also lists examples of ethical action. These are listed in the section "What Can We Do" in the Instructor's Guide.

One of the requirements in a user's guide to caring for the Earth (The World Conservation Union/United Nations Environment Programme/World Wide Fund for Nature 1992:3) is "to secure a widespread and deeply - held commitment to a new ethic, the ethic for sustainable living, and to translate its principles into practice." The guide states that environmental values and criteria should be incorporated as key factors in all national and business decision processes. This user's guide contains many recommendations (many of them regarding global warming) in a setting of environmental ethics and values.

Although these sources contain many instructions on what to do, teaching people how to make ethical decisions should also be emphasized (Aikenhead 1993, p. comm.). This would be appropriate for future work in this area.

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Climatic Change Glossary

E.E. Wheaton

* Definitions which are useful for the student exercise on shifting ecoclimates (Appendix A).

Acid Precipitation (rain) - the deposition of strong acids from the atmosphere in the form of rain, snow, fog or dry particles. The acid in the rain is the result of pollution caused primarily by the discharge of sulphur oxides and nitrogen oxides into the atmosphere from the burning of coal and oil, during the operation of smelting industries and from transportation. In the atmosphere these gases combine with water vapour to form acids. The pH of rain is naturally somewhat acidic. Precipitation in uncontaminated remote areas usually has a pH of about 5 (Lutgens and Tarbuck 1992).

Aerosol - a suspension of fine liquid or solid particles in a gas (e.g., smog, fog, mist).

* Aspen Parkland - the transition zone between the boreal forest and the grassland, consisting of a mosaic of aspen and grassland patches.

Atmosphere - the envelope of air surrounding the Earth. Most weather events are confined to the troposphere, the lower approximately 10 kilometres of the atmosphere.

* Boreal Forest - the vegetation zone extending across northern Canada and Eurasia that is dominated by a few species of cold tolerant conifers.

Carbon Dioxide (CO2) - the most important and abundant greenhouse gas, accounting for about two-thirds of the greenhouse effect. The 25% increase in CO2 since 1880 is attributed principally to combustion of fossil fuel from industrialization and deforestation.

Chlorofluorocarbons (CFCs) - gases that are compounds of carbon, fluorine and chlorine. In addition to contributing to greenhouse warming, CFCs deplete stratospheric ozone, which leads to increased harmful ultra-violet radiation at the Earth's surface. CFCs are used in refrigerants, aerosols, insulating material and solvents.

* Climate - the synthesis of day-to-day weather variations in a locality. The climate of a specified area is represented by the statistical collection of its weather conditions during a specified interval of time, which is usually taken to include the following weather elements: temperature, precipitation, humidity, sunshine, and wind velocity.

* Climatic Change - describes longer-term changes in values of specific climatic variables between average periods.

Climatic Variability - describes the observed year-to-year differences in values of specific climatic variables within an averaging period (typically 30 years).

Drought - an extended period of dry weather that lasts longer than expected or than normal and leads to measurable losses (crop damage, water supply shortages, etc.)

* Ecoclimatic Region - a large area of the Earth's surface characterized by distinctive ecological responses to climate, as expressed by vegetation, and reflected in water, soils and wildlife.

* Ecosystem - an integrated and stable association of living and nonliving resources functioning within a defined physical location. The term may be applied to a unit as large as the entire Ecosphere. More often it is applied to some smaller division.

Evaporation/Evapotranspiration (of water) - the physical process by which water is transferred from the Earth's surface to the atmosphere through the evaporation of water or ice into water vapour, and through transpiration from plants.

* Forest Tundra - the northern most part of the subarctic zone, where trees are confined to valleys and tundra occurs on ridges.

* Grassland - vegetation zone dominated by grasses, generally occurring in climates too dry for tree growth.

* Growing Season - the part of the year when the growth of natural and cultivated vegetation is made possible by sufficiently high temperatures, usually when the average daily temperature remains above 5°C.

* Growing Degree-Day - a measure of the departure of the mean daily temperature from a base temperature (typically 5°C); one degree-day for each degree of departure above this standard during one day.

* Greenhouse Effect - a popular term used to describe the roles of water vapour, carbon dioxide and other trace gases in keeping the Earth's surface warmer than it would be otherwise. These "radiatively active" gases are relatively transparent to incoming shortwave radiation, but are relatively opaque to outgoing long wave radiation. The latter radiation, which would otherwise escape to space, is trapped by these gases within the lower levels of the atmosphere. The subsequent reradiation of some of the energy back to the surface maintains surface temperatures higher than they would be if the gases were absent. There is concern that increasing concentrations of greenhouse gases, including carbon dioxide, methane and chlorofluorocarbons, may enhance the greenhouse effect and cause global warming.

* Greenhouse Gases (a popular term for radiatively active gases) - those gases, such as water vapour, carbon dioxide, tropospheric ozone, nitrous oxide, and methane, that are transparent to solar radiation but opaque to long wave radiation. Their action is similar to that of glass in a greenhouse, but the process causing warming in a greenhouse differs from that involved in the greenhouse effect. Thus, the terms greenhouse effect and greenhouse gases are misnomers. Also see greenhouse effect.

Heat Island - the region of warm air over a city where temperatures are higher than in surrounding rural areas.

Heat Wave - a period with more than three consecutive days of maximum temperatures at of above 32°C.

* Interpolate - to estimate values of a function between two known values; to make insertions of estimated values.

* Isoline - lines joining points of equal values. Some examples include contour lines, isotherms and isobars.

* Latitude - angular distance north or south from the Earth's equator measured through 90 degrees. For example, the Saskatoon Climate Reference Station is at about 52° 09¢ North latitude.

* Longitude - the arc or portion of the Earth's equator intersected between the meridian of a given place and the prime meridian (as from Greenwich, England) and expressed either in degrees or in time. For example, the Saskatoon Climate Reference Station is at about 106° 36¢ W longitude.

Methane (CH4) - a hydrocarbon also known as natural gas. Sources include ruminant livestock, rice paddies, biomass burning, coal mining, oil production, landfills, and wetlands.

Nitrous Oxide (N2O) - a colourless gas derived from fossil fuel and biomass combustion, fertilizers, landfills and coal seams.

Radiational Cooling - the cooling of the Earth's surface and nearby air that results when the surface loses more heat than it gains.

Solar radiation spectrum - the range of different types of wavelengths of the radiant energy from the sun. The solar radiation spectrum consists of (a) X-rays, gamma rays and ultraviolet rays (about 9% of the total energy); (b) visible light rays (about 41%) and (c) invisible infrared and heat rays (50%).

Sustainable Development - development that ensures that the use of resources and the environment today does not damage prospects for their use by future generations.

* Tundra - vegetation zone dominated by low plants (mosses, lichens, dwarf shrubs, grasses, and sedges), occurring in climates too cold for tree growth.

Volcanic aerosols - fine solid or liquid particles suspended in the atmosphere as a result of volcanic eruptions.

Weather - state or condition of the atmosphere with respect to heat or cold, wetness or dryness, calm or storm, and clearness or cloudiness for a certain period of time.

Sources of definitions: Millenann (1988); Ecoregions Working Group (1989); Hogan (1992); Phillips (1990); Rosenzweig and Ropes (1990); Strahler (1979); Webster's Dictionary; Wheaton et al. (1987).

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