This guide points K-12 educators to the best sites for teaching about climate change: several that offer first rate background material, and othersthat include detailed lesson plans and experiments. It begins with Top Ten Things You Need to Know about Global Warming and a note about why there is so much controversy surrounding this issue.
Climate change is a great topic for students to study because it integrates so many subjects: energy, environment, geography, politics, chemistry, biology, economics, and more. It requires students to use analytical tools and math skills, and to exercise their abilities to research, think and understand complex issues. The web sites reviewed in this guide offer everything you need to create your own unit on climate change and global warming.
There are a number of widely held misconceptions about climate change, and unfortunately, these are reflected in some of the educational materials available on the web. It is therefore crucial for teachers to educate themselves and their students with accurate information and be careful not to reinforce common but incorrect notions. The following primer is a good place to begin.
Certain gases that trap heat are building up in Earth's atmosphere. The primary culprit is carbon dioxide, released from burning coal, oil and natural gas in power plants, cars, factories, etc. (and to a lesser extent when forests are cleared). The second is methane, released from rice paddies, both ends of cows, rotting garbage in landfills, mining operations, and gas pipelines. Third are chlorofluorocarbons (CFCs) and similar chemicals, which are also implicated in the separate problem of ozone depletion (see #5 below). Nitrous oxide (from fertilizers and other chemicals) is fourth.
#2 Earth's average temperature has risen about 1 degree F in the past 100 years and is projected to rise another 3 to 10 degrees F in the next 100 years.
While Earth's climate has changed naturally throughout time, the current rate of change due to human activity is unprecedented during at least the last 10,000 years. The projected range of temperature rise is wide because it includes a variety of possible future conditions, such as whether or not we control greenhouse gas emissions and different ways the climate system might respond. Temperatures over the US are expected to rise more than over the globe as a whole because land areas closer to the poles are projected to warm faster than those nearer the equator.
#3 There is scientific consensus that global warming is real, is caused by human activities, and presents serious challenges.
Scientists working on this issue report that the observed global warming cannot be explained by natural variations such as changes in the sun's output or volcanic eruptions. The most authoritative source of information is the UN Intergovernmental Panel on Climate Change (IPCC) which draws upon the collective wisdom of many hundreds of scientists from around the world. The IPCC projects global temperature increases of 3 to 10 degrees F in the next 100 years and says that human activity is the cause of most of the observed and projected warming.
#4 There's a difference between weather and climate.
Weather refers to the conditions at one particular time and place, and can change from hour to hour, day to day, and season to season. Climate, on the other hand, refers to the long-term average pattern of weather in a place. For example, we might say that the climate of South Florida is warm, moist and sunny, although the weather on a particular day could be quite different than that. Long-term data are needed to determine changes in climate, and such data indicate that Earth's climate has been warming at a rapid rate since the start of intensive use of coal and oil in the late 1800s.
#5 The ozone hole does not cause global warming.
Ozone depletion is a different problem, caused mainly by CFCs (like Freon) once used in refrigerators and air conditioners. In the past, CFCs were also used in aerosol spray cans, but that use was banned in the US in 1978. CFCs deplete the stratospheric ozone layer that protects life on Earth from excess ultraviolet light that can cause skin cancer and cataracts in humans and other damage to plants and animals. An international agreement has phased out most uses of CFCs but the ozone layer is only just beginning to recover, partly because these chemicals remain in the atmosphere for a long time. (Although ozone depletion is not the cause of global warming, there are a number of connections between the two. For example, many ozone-depleting compounds are also greenhouse gases. Some of the compounds now replacing CFCs in order to protect ozone are also greenhouse gases. And ozone itself is a greenhouse gas. In addition, while greenhouse gas build-up causes temperatures close to Earth's surface to rise, it cause temperatures higher up, in the stratosphere, to fall. This stratospheric cooling speeds ozone depletion, delaying the recovery of the ozone hole.)
#6 Global warming will have significant impacts on people and nature.
As temperatures continue to rise, precipitation is projected to come more frequently in the form of heavy downpours. We can probably expect more extreme wet and dry conditions. In the western US, where snowpack provides free storage of most of the water supply, reduced snowpack will make less water available in summer. Coastal areas will become more vulnerable to storm surges as sea level rises. Plant and animal species will migrate or disappear in response to changes in climate; New England may lose its lobsters and maple trees as they move north into Canada. Natural ecosystems such as coral reefs, mangrove swamps, arctic tundra, and alpine meadows are especially vulnerable and may disappear entirely in some areas. While global warming will have impacts on natural and human systems all around the world, the largest impacts will be on many natural ecosystems and on people who live in developing countries and have few resources and little ability to adapt. On the positive side, warmer winters will reduce cold-related stresses and growing seasons will lengthen. And there will be tradeoffs in some areas, such as less skiing but more hiking; and fewer killing frosts but more bugs.
#7 Sea level has already risen due to warming and is projected to rise much more.
Many people are under the mistaken impression that only if the polar ice caps melt will sea level rise. In fact, average sea level around the world has already risen 4 to 8 inches in the past 100 years due to global warming and is expected to rise another 4 to 35 inches (with a best guess of around 19 inches) by 2100. The primary reason for this rise is that water expands as it warms. The second reason is that glaciers all over the world are melting, and when land-based ice melts, the water runs to the sea and increases its level. Thousands of small islands are threatened by the projected sea-level rise for the 21st century, as are low-lying coastal areas such as southern Florida. Of course, if there is any significant melting of the polar ice sheets, the additional rise in sea level would be enormous (measured in feet not inches). This is projected to occur on a time scale of millennia rather than centuries.
#8 Saving energy and developing alternative energy sources would help.
Each of us can reduce our contribution to global warming by using less greenhouse-gas-producing energy: driving less, choosing fuel efficient cars and appliances (like refrigerators and water heaters), and using solar energy where feasible for water and space heat. We can encourage our political and business leaders to institute policies that will save energy and develop alternative energy sources that do not release carbon dioxide. We can preserve existing forests and plant new ones. But even if we take aggressive action now, we cannot completely prevent climate change because once carbon dioxide is in the atmosphere, it remains there for about a century, and the climate system takes a long time to respond to changes. But our actions now and in the coming decades will have enormous implications for future generations.
#9 An international agreement known as the Kyoto Protocol has been negotiated to reduce greenhouse gas emissions, but the US is not participating in it.
Because of its high energy consumption, the US has long emitted more carbon dioxide than any other country. Because carbon dioxide remains in the atmosphere for about 120 years, it accumulates, becomes equally distributed around the world, and has global effects. Thus, while using large amounts of energy to achieve economic growth, the US and other wealthy nations have unintentionally burdened the rest of the world with a long-term problem. And many negative impacts of climate change are likely to be more severe for poorer countries that lack the resources to adapt. The US has more technological and financial resources than other nations. The role of the US in reducing its own emissions and sharing its technologies with other nations will thus be critical to the success of international efforts to limit climate change. Meanwhile, we do not have to wait for the government to take action. Some companies, governments and individuals have already committed to reducing their emissions of greenhouse gases without laws or treaties requiring them to do so.
#10 Protecting the world's climate by stabilizing atmospheric concentrations of greenhouse gases will require enormous reductions in current emissions.
Even if ratified, the Kyoto Protocol in its present form is only a start and would not be nearly enough to stabilize climate. It is estimated that greenhouse gas emissions would have to be reduced to less than one third of current levels to stabilize atmospheric concentrations. This would require a major transformation of the energy sector. A mix of new and existing energy technologies will be needed to achieve this, including large increases in energy efficiency and renewable energy. Researchers are also developing technology to capture and bury carbon dioxide thousands of feet underground. Major increases in public and private research and development are needed to make the necessary technologies available as rapidly and economically as possible.
Why So Much Controversy?
With such strong scientific consensus that global warming is real and is largely due to human activities, why is there so much controversy in the press and among the public? Why do some people keep insisting it is just an unproven theory? Some reasons involve communication breakdowns, but even more important is the deliberate campaign by special interests, including some in the fossil fuel industry, to undermine or cast doubt on the science.
Climate science can be confusing and is not easily explained in sound bites or brief newspaper articles. Many well-intentioned reporters are ill equipped to get the story right and their mistakes are often perpetuated as other reporters use previous articles as source material for new ones. Partly as a result of such problems, many people erroneously believe that global warming is caused by increased heat entering the atmosphere due to ozone depletion caused by CFCs.
In addition, most scientists discuss their research in terms that the public cannot easily understand. They also use some words that mean different things to a lay audience than they do to scientists. For example, when scientists speak of "aerosols," they are referring to tiny atmospheric particles, while to lay people, an "aerosol" is a spray can.
But the most significant reason for the controversy is that some special interests have mounted an active campaign to raise doubts and create confusion about this issue. For legitimate and other reasons, a very small number of scientists raise questions about whether warming has or will occur. When they do, special interests work hard to amplify and distribute the views of these "contrarians" in order to create confusion among the press, policymakers and public and give the impression that there is still a major scientific debate about the reality and causes of climate change. (Note: not all fossil fuel companies are implicated in this disinformation campaign. Some, in fact, have acknowledged the scientific realities and are taking steps to reduce their greenhouse gas emissions [see a list of such companies at the Pew Center on Global Climate Change]).
Given all this confusion and controversy, it is particularly important that teachers and students have access to reliable information about climate change. It is our hope that this teachers guide will be of some assistance toward that end.
EPA GLOBAL WARMING SITE
You can get up to speed on climate change issues quickly and efficiently at this site from the US Environmental Protection Agency. "Frequently Asked Questions" (FAQ) is a good place to begin. Another good section, "In the News," offers brief summaries of the latest developments in climate science and policy and provides links for further details. "Publications" provides links to authoritative reports from the top sources. "Outreach" offers a variety of very useful fact sheets (basic to advanced) to get you and your students started, as well as brochures that deal with particular aspects of the subject, such as "Climate Change and Birds" and "Climate Change and Public Lands." One fact sheet, "Straight Talk on Global Warming," deals with some of the most common misunderstandings and misrepresentations about the issue.
The "Outreach" section also includes publications that deal with policies and technological strategies for reducing human-induced climate change. Links to online tools are provided for calculating emissions reductions from various strategies. These tools can easily form the basis of classroom activities such as calculating carbon dioxide emissions reductions from walking to school instead of being driven, thus helping students relate personally to this global scale issue. The glossary is quite extensive and fairly technical and is a great resource for teachers and more advanced high school students.
A much simpler and far less comprehensive glossary for younger students can be found at EPA's Global Warming Kids Page. Elementary and Middle School students will find this page an accessible place to begin. It includes simple explanations of the issues and characterizes scientists as "climate detectives" searching for clues in ice cores, tree rings and satellite data. It also provides links and games to appeal to younger students.
UN CLIMATE INFORMATION KIT
This is an excellent resource for information on climate change from the United Nations, World Meteorological Organization, and five other international agencies. The 63-page guide (downloads in pdf) is clearly written in plain English, and offers comprehensive information on the science of global climate change, potential impacts, adaptation and mitigation strategies, and policies. This policy emphasis - what the world is doing about climate change - sets this material apart. Data charts, including greenhouse gas emissions and their sources, are another useful feature. This thorough guide was updated in the summer of 2001 with information from the latest reports of the Intergovernmental Panel on Climate Change (IPCC), the leading authority on the subject. Note: International units are used in this guide, so take this opportunity to familiarize your students with converting degrees Celsius to Fahrenheit and metric measurements to English ones (e.g., meters to feet).
Additional Technical Resources
INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE
Teachers and older students who want more detailed technical information and a global perspective can go directly to the reports of the Intergovernmental Panel on Climate Change (IPCC). The IPCC was organized under the auspices of the United Nations and represents the combined wisdom of the world's leading climate scientists. "Summaries for Policymakers" are available on line for the three working groups of the IPCC: I. the scientific basis of climate change, II. impacts, adaptation and vulnerability, and III. mitigation, as well as several special reports.
US NATIONAL ASSESSMENT OF CLIMATE CHANGE IMPACTS
To gain a better understanding of what global warming will mean for the United States, visit the site of the US National Assessment of the Potential Consequences of Climate Variability and Change. The 150-page "Overview" report, "Climate Change Impacts on the US," is full of information and is written in accessible language, while the much longer "Foundation" document is a more technical report with scientific references. Both deal with climate change and its projected impacts on each region of the US and on five key sectors: agriculture, water, human health, forests, and coastal areas and marine resources.
PEW CENTER ON GLOBAL CLIMATE CHANGE
The Pew Center on Global Climate Change is an independent, non-partisan organization dedicated to providing credible information and innovative solutions to addressing climate change. Funded by the Pew Charitable Trusts and other sources, the Center produces reports by leading experts on climate change science, economics, policies, and solutions. It has also enlisted dozens of major companies in an effort to use the power of the marketplace to address climate change. The website offers an excellent set of resources that are useful for teachers and more advanced students, from the full text of the Center's reports, to current articles and editorials, to lists of sites for more information.
UNION OF CONCERNED SCIENTISTS (UCS) CURRICULUM GUIDE
The UCS has produced a set of teaching materials designed to accompany "Global Warming: Early Warning Signs"- a science-based world map depicting local and regional consequences of global climate change. The map can be found at www.climatehotmap.org/. While UCS and the other organizations that produced the map are advocacy groups that call for policy actions on climate change, the lesson plans in the UCS Curriculum Guide are scientifically accurate, pedagogically sound, and do not reflect a bias. Rather, they encourage students to collect and analyze data and draw their own conclusions.
The 30-page Curriculum Guide is geared towards grades 9-12, but individual exercises are adaptable to other grade levels. Each activity is structured to include an initial "Engagement" exercise, one or more steps of a student "Exploration" project, and ideas for extended study. The activities align with National Learning Standards for Science, Geography, Social Studies, Language Arts, Environmental Education, and Technology, and the specific standards addressed by each activity are identified.
The web resources suggested for teacher and student use are authoritative and first rate.
Four activities are presented:
Climate Change in My City: Students use an historical climate index to analyze climate change at local, regional, and global scales.
Oral History Project: Students interview older residents in the community about climate changes during their lifetime and compare the results to a climate change index that is based on historical temperature measurements.
Climate Change and Disease: Students research the relationship between hosts, parasites, and vectors for common vector-borne diseases and evaluate how climate change could affect the spread of disease.
Climate Change and Ecosystems: Students research the interdependencies among plants and animals in an ecosystem and explore how climate change might affect those interdependencies and the ecosystem as a whole.
US DEPARTMENT OF ENERGY'S ARM EDUCATION SITE AND LESSON PLANS
The Atmospheric Radiation Measurement (ARM) Program is part of the US Department of Energy's strategy to understand global climate change. The lesson plans available at this site were designed for middle school grade levels, but can be modified by the teacher for both the high school and elementary levels. The lesson plans include objectives, materials needed, important points to understand, preparation steps, and procedures. These are fairly traditional science experiments but are of good quality and scientific accuracy.
The 40 lesson plans cover a variety of basic climate issues such as the composition and structure of the atmosphere, why the Earth is hotter at the equator, and the reasons for the seasons. The lessons also delve into the details of climate change and its impacts; for example, there are several lessons that illustrate why sea level rises in a warming climate. Teachers can choose from among these 40 lessons and develop an excellent series on climate change. Background information is needed for most lessons and is provided at the site. It is thorough without being overwhelming, though teachers may have to help some students in understanding the more technical information. The site also gives two quizzes (one basic and one more advanced) to test students understanding. These are graded instantly on line, with each answer explained.
Another excellent resource on the ARM site is the list of frequently asked questions sent in by students, along with answers from an ARM scientist. A tremendous amount of information can be found in these answers and they respond to very common questions and misconceptions among students and the public in general. Some answers also identify additional websites as sources of further information. The section "Cool Sites" offers a good selection of additional resources on the web.
What Can I Do About It?
After learning about climate change, some students may want to know what they as individuals can do about it. This site from Environmental Defense offers 20 simple steps to reduce an individual's contribution to global warming and gives the approximate carbon dioxide reduction attained by taking each step. While Environmental Defense is an advocacy group that supports strong measures to mitigate climate change, the suggested actions are simply those that are widely recommended to reduce energy use and its environmental impacts.
Searching the Web for Other Materials
Climate and weather have long been important science subjects. Increasing concern about human activities altering Earth's climate makes these ever more relevant areas of inquiry. Finding high quality background materials and lesson plans can be a challenge. Sorting through the plethora of information posted on the Internet, some of dubious quality, is notoriously difficult.
Internet searches for climate change education materials yield hundreds of websites, many of which are poor in quality. Some reflect a bias that global warming is either not occurring or is nothing to be concerned about. Others reflect an opposite bias: that every harmful weather event is caused by global warming and that the effects of climate change will be cataclysmic everywhere. Still others contain major or minor scientific errors.
It is therefore essential to determine the credibility of any information you come across. What is the source? For example, weather reporters of local television stations are not leading authorities on climate change. And some groups with green sounding names, like the Global Climate Coalition, are actually lobbying and advocacy arms of some in the fossil fuel industry. If you come across "The World Climate Report," for example, you'll see that it bills itself as "the nation's leading publication covering the breaking news concerning the science and political science of global climate change." But in fact, it presents a view that is radically contrary to the scientific consensus on this issue. It is published by the "Greening Earth Society," whose mission, funded by some in the fossil fuel industry, is to discredit the science of climate change and prevent action on this issue.
In addition, many errors of scientific fact are extremely widespread, and because they have been repeated so often, they can be easily mistaken for truth. Examples of widespread errors include confounding the issues of climate and ozone, and mistakenly citing polar ice cap melting as the leading cause of current sea level rise due to warming. The bottom line: use extreme caution when choosing materials from the web and always carefully consider the source.
Susan Joy Hassol, 2000-2002
Glaciers are melting, sea levels are rising, cloud forests are dying, and wildlife is scrambling to keep pace. It's becoming clear that humans have caused most of the past century's warming by releasing heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than in the last 650,000 years.
We call the result global warming, but it is causing a set of changes to the Earth's climate, or long-term weather patterns, that varies from place to place. As the Earth spins each day, the new heat swirls with it, picking up moisture over the oceans, rising here, settling there. It's changing the rhythms of climate that all living things have come to rely upon. [Watch Polar Bears 101].
What will we do to slow this warming? How will we cope with the changes we've already set into motion? While we struggle to figure it all out, the face of the Earth as we know it—coasts, forests, farms and snow-capped mountains—hangs in the balance.
The "greenhouse effect" is the warming that happens when certain gases in Earth's atmosphere trap heat. These gases let in light but keep heat from escaping, like the glass walls of a greenhouse.
First, sunlight shines onto the Earth's surface, where it is absorbed and then radiates back into the atmosphere as heat. In the atmosphere, “greenhouse” gases trap some of this heat, and the rest escapes into space. The more greenhouse gases are in the atmosphere, the more heat gets trapped.
Scientists have known about the greenhouse effect since 1824, when Joseph Fourier calculated that the Earth would be much colder if it had no atmosphere. This greenhouse effect is what keeps the Earth's climate livable. Without it, the Earth's surface would be an average of about 60 degrees Fahrenheit cooler.
In 1895, the Swedish chemist Svante Arrhenius discovered that humans could enhance the greenhouse effect by making carbon dioxide, a greenhouse gas. He kicked off 100 years of climate research that has given us a sophisticated understanding of global warming.
Levels of greenhouse gases (GHGs) have gone up and down over the Earth's history, but they have been fairly constant for the past few thousand years. Global average temperatures have stayed fairly constant over that time as well, until recently. Through the burning of fossil fuels and other GHG emissions, humans are enhancing the greenhouse effect and warming Earth.
Scientists often use the term "climate change" instead of global warming. This is because as the Earth's average temperature climbs, winds and ocean currents move heat around the globe in ways that can cool some areas, warm others, and change the amount of rain and snow falling. As a result, the climate changes differently in different areas.
Aren't temperature changes natural?
The average global temperature and concentrations of carbon dioxide (one of the major greenhouse gases) have fluctuated on a cycle of hundreds of thousands of years as the Earth's position relative to the sun has varied. As a result, ice ages have come and gone.
However, for thousands of years now, emissions of GHGs to the atmosphere have been balanced out by GHGs that are naturally absorbed. As a result, GHG concentrations and temperature have been fairly stable. This stability has allowed human civilization to develop within a consistent climate.
Occasionally, other factors briefly influence global temperatures. Volcanic eruptions, for example, emit particles that temporarily cool the Earth's surface. But these have no lasting effect beyond a few years. Other cycles, such as El Niño, also work on fairly short and predictable cycles.
Now, humans have increased the amount of carbon dioxide in the atmosphere by more than a third since the industrial revolution. Changes this large have historically taken thousands of years, but are now happening over the course of decades.
Why is this a concern?
The rapid rise in greenhouse gases is a problem because it is changing the climate faster than some living things may be able to adapt. Also, a new and more unpredictable climate poses unique challenges to all life.
Historically, Earth's climate has regularly shifted back and forth between temperatures like those we see today and temperatures cold enough that large sheets of ice covered much of North America and Europe. The difference between average global temperatures today and during those ice ages is only about 5 degrees Celsius (9 degrees Fahrenheit), and these swings happen slowly, over hundreds of thousands of years.
Now, with concentrations of greenhouse gases rising, Earth's remaining ice sheets (such as Greenland and Antarctica) are starting to melt too. The extra water could potentially raise sea levels significantly.
As the mercury rises, the climate can change in unexpected ways. In addition to sea levels rising, weather can become more extreme. This means more intense major storms, more rain followed by longer and drier droughts (a challenge for growing crops), changes in the ranges in which plants and animals can live, and loss of water supplies that have historically come from glaciers.