What is the source of almost all energy on earth

The sun warms the planet, drives the hydrologic cycle, and makes life on Earth possible. The amount of sunlight received on Earth's surface is affected by the reflectivity of the surface, the angle of the sun, the output of the sun, and the cyclic variations of Earth's orbit around the sun.

The basic science of solar energy and the role it plays for Earth's climate can be understood by middle school students, but the complexities of the Earth's energy balance remains an area of active scientific research. Thus, this topic is both elemental and complex.

This principle is related to Energy Literacy Principle 2: Physical processes on Earth are the result of energy flow through the Earth system.

Show students the basic mechanics of the climate system

Understanding the role of solar radiation in the Earth's climate system can help us grasp important concepts such as:

The causes of the seasons.

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Seasons are caused by the tilt of Earth's axis. The tilted axis means that the northern and southern parts of Earth do not receive equal amounts of solar radiation (energy per unit area). When the southern hemisphere is tilted toward the sun, it is summer in the southern hemisphere and winter in the northern hemisphere. (Principle 1c)

The reasons ice ages occur.

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The ice ages were caused by changes in the distribution of solar radiation received over Earth's surface. The path of Earth's orbit is not constant. Variations in Earth's orbital path causes the solar radiation reaching any point on Earth's surface to change. (Principle 1d)

 
How the amount of energy emitted from the sun (sun's luminosity) changes over time.

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The sun's output is not constant. Its luminosity (total energy emitted by the sun) has increased over geologic time, and varies slightly over shorter time scales.

 
Why recent climate warming has not been caused by increases in the sun's energy output.

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The sun's energy output has not changed enough over the last decades to account for the increases in temperatures that have been observed during this same time. (Principle 1e)

 
Most forms of energy that humans use are derived from solar energy.

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Many forms of energy that humans use ultimately derive from solar radiation, such as food, hydrocarbons (such as oil and natural gas), wind energy, hydroelectric power, and of course, solar energy.

Helping students understand these ideas

Throughout most science education programs and standards, the role of the sun in providing energy to the Earth system is included, but often in a disjointed way. The seasons and their importance in driving seasonal weather patterns and animal migration may be taught in primary school and then not revisited for many years, if at all.

Moreover, students of all ages, including college students and adults, have difficulty understanding what causes the seasons. In addition to the axial tilt, factors that come into play in people's mental models include the belief that Earth orbits the sun in an elongated elliptical path; confusion about the relative size, motion, and distance of the earth from the sun; how light travels; the length of Earth's revolution around the sun; and even the period of rotation. One strategy to mitigate this common misconception is to ensure that the "reasons for the seasons" are adequately addressed in high school, when students have sufficient background in geometry and physics to grasp the concepts (McCaffrey & Buhr, 2008).

A persistent misconception is that our recent climate warming is due to changes in the sun's incoming energy, rather than increases of greenhouse emissions. This can be addressed by examining records of solar output and comparing them to global temperature records. The data clearly shows that the sun's irradiance is not correlated with Earth's temperature.

Excellent explanations for this can be found at Skeptical Science: Sun and Climate: Moving in Opposite Directions and with a graphic from Bloomberg: What's Really Warming the World? This engaging graph is made with NASA data and model output.

Bringing these ideas into your classroom

Solar radiation is the fundamental energy driving our climate system, and nearly all climatic and biologic processes on Earth are dependent on solar input. Energy from the sun is essential for many processes on Earth including warming of the surface, evaporation, photosynthesis and atmospheric circulation. Thus, examining how the sun fuels different processes on Earth can be a part of many types of science courses. Many of the science concepts relating to this principle can be addressed by encouraging seasonal observations, participating in citizen science programs with students (such as GLOBE), and periodically revisiting the basics of how the amount and intensity of solar energy affects Earth's climate.

The ways that the Sun's energy drives the climate system can be taught from a very basic level on upward through the most sophisticated scientific approaches.

Integrating Solutions - The science concepts that relate to solar radiation can be expanded to include solar energy engineering and technology, including solar ovens, passive solar design, solar thermal energy and solar electricity. This can help raise awareness for alternatives to the use of fossil fuel and create a forum for discussions about solutions to climate change that our society can adopt.

Teaching materials from the CLEAN collection

Middle school

• Globes and other physical models can be used to show the tilt of Earth's axis and how that affects the distribution of sunlight during different seasons, such as in My Angle on Cooling: Effects of Distance and Inclination.
• Introduction to Earth's Climate - This lesson is an introduction to Earth's climate and covers key principles regarding Earth's unique climate, atmosphere, and regional and temporal climate differences.
• Feeling adventuresome? Amazing Albedo is a hands-on activity that involves measuring the temperature of different colored surfaces.

High school

• The Climate: A Balancing Act applet allows students to adjust parameters that affect Earth's energy balance: incoming solar radiation, the albedo effect, the greenhouse effect, and outgoing radiation.
• Students can learn how orbital cycles and ice ages are well correlated with the Milankovitch Cycles Climate Applet.
• This Seasons Interactive visualization tool can become the basis for open-ended exploration of how solar radiation varies with location and season.
• The Solar Influence: Climate Change video from the National Academies can help reinforce the evidence that solar activity is not causing global warming.

College

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References

What's the Sun's Role in Climate Change? - NASA offers an readable yet authoritative look at why solar activity, solar cycles, and sunspots are not related to today's climate warming. NASA has a related post that debunks the myth of an impending ice age.

Sun and Climate: Moving in Opposite Directions This page from the Skeptical Science website provides clear answers to common questions and misunderstandings about climate change.

What's Really Warming the World? - This animated graphic compares different forcings that are acting on Earth's climate. Climatic changes caused by orbital variation, the sun's luminosity, and volcanic emissions are compared with the effect of greenhouse emissions. The graphic is very engaging and the data is from NASA's Goddard Institute for Space Studies (GISS).

McCaffrey & Buhr, 2008: Clarifying Climate Confusion. - Journal article from Physical Geography about common misconceptions in climate science.

Page 2

Earth's climate is governed by several different types of processes.

Oceanic, atmospheric, biologic, and geologic processes all drive the climate system and result in regional differences in climates on Earth. Many climatic processes such as the greenhouse effect and the carbon cycle are the result of the interplay between the "spheres" of the Earth system (atmosphere, cryosphere, geosphere, biosphere). Feedbacks between various components work to exacerbate or mitigate changes to the climate.

Climate cycles, feedbacks, and interplay between causes and effects

These ideas address some of the natural complexities of our climate system and build a foundation for the understanding of key components such as the carbon cycle, the greenhouse effect, and interactions and feedback loops. These topics are active areas of climate research and include important questions such as:

• How aerosols play a role in the changing climate. These small airborne particles have both a cooling and warming effect and originate from both natural and human-caused sources.
• How feedbacks in the climate system contribute to the effects of increasing atmospheric CO2.
• How oceanic processes are integral in the distribution of heat, absorption of CO2, and changes in circulation patterns.
• Why some past climate changes have been gradual and others abrupt.

On a more basic level, the processes covered in this principle can easily be observed, such as:

• Compared to air, water takes a long time to warm up or cool down.
• A cloudy night will be warmer than a clear night (if all other factors remain equal).
• The overall climate of a region is not solely determined by its latitude but is also influenced by factors such as proximity to oceans or mountain ranges.

Helping students understand these ideas

The natural greenhouse effect is a common area of misunderstanding. Educators should strive to explain this concept in a way that is as simple as possible but is still accurate.

• Most of the Sun's energy that reaches Earth's surface is short wave radiation, which warms the surface and is transformed into long-wave infrared that radiates back toward space.
• Most of the gases in the atmosphere do not trap the outgoing radiation.
• However, greenhouse gases in the atmosphere such as water vapor, carbon dioxide, methane, and nitrogen oxides are very powerful in absorbing the outgoing radiation and re-radiating it in all directions.
• The re-radiation of energy causes the lower atmosphere to warm, and in turn, warms Earth's land surface and oceans.

Attempts to oversimplify the greenhouse effect can be counter-productive and further confuse learners. For younger students, the mental model of how the natural greenhouse effect is like a "blanket" that keeps heat under the covers may be appropriate, but a key difference is that a blanket retains heat that is generated by your body (or the Earth, in the analogy). In reality, the heat energy is originally coming from the Sun, not from the Earth.

High school and certainly, college students should have a clearer understanding of the mechanics of the greenhouse effect. This concept is essential to understanding how human activities are impacting the climate system.

Full comprehension of the carbon cycle requires an understanding of biogeochemical systems. Students also have to understand the different time scales at which carbon exchange takes place in the different reservoirs. Learning about the carbon cycle lays an important foundation to the understanding of the impact of burning fossil fuels. As shown in the famous Harvard Private Universe study, students struggle to build the connection between mass production through photosynthesis and carbon uptake, the burial of biomass, and fossil fuels - all these concepts are part of the carbon cycle.

The terminology of positive and negative feedback in a system can often lead to misunderstanding because the words 'positive' and 'negative' have other meanings. It is clearer to use the term 'self-reinforcing cycle' to describe the way that positive feedback can amplify the initial input. Negative feedback can be termed a 'self-dampening cycle.'

Bringing these ideas into your classroom

Just because a process is complex does not mean it needs to be complicated. Teaching these basic climate science topics may be best handled by an approach that allows depth over breadth. If students are able to address a single topic with sufficient depth, they can come to an understanding of nuances like feedback loops or deep ocean circulation. So a good tactic would be to set aside time to explore a topic and several facets within it. An important part of climate literacy is an appreciation for scientific complexity, and even young learners can comprehend that a seemingly simple and linear process can be quickly complicated by other factors.

Another strategy for teaching these principles is the Earth systems science approach. This method teaches students about the "spheres" of the Earth system: the atmosphere, cryosphere, geosphere, and biosphere. An Earth systems approach is an effective way to illustrate the interplay between different components of Earth and that processes do not occur in isolation. Learn more and find specific examples from the InTeGrate project: Teach Systems Thinking or Incorporating Systems Thinking in the Classroom.

Teaching materials from the CLEAN collection

Middle school

High school

• This short Greenhouse Effect Video from atmospheric scientist Scott Denning gives a candid and entertaining explanation of how greenhouse gases in Earth's atmosphere warm our planet. This video could also be useful for professional development for teachers.
• Ocean Currents and Sea Surface Temperature students access sea surface temperature and wind speed data from a NASA site, plot and compare data, draw conclusions, and link them to the topic of global climate change.
• Carbon on the Move is a 3-part lab activity where students investigate the global carbon cycle and study the effects of specific feedback loops.
• A slide show and case study from the New York Times shows one example of self-reinforcing feedback occurring today, As Permafrost Thaws, Scientists Study the Risks.
• Students can explore feedbacks further with this data-rich activity that examines albedo and the rate of snowmelt in the Arctic, Arctic Climate Curriculum: Exploring Arctic Climate Data.

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References

The Study of Earth as an Integrated System from NASA - a quick "explainer" on the various components of the climate system, including forcings, feedbacks, and tipping points.

What Factors Determine Earth's Climate? from the IPCC - a dense, one-page summary of the climate system, complete with a classic diagram of Earth's energy balance.

Carbon and Climate - an educational website with a carbon cycle applet for modeling your own projection on carbon emissions and future carbon sinks.

Page 3

Life affects the climate system and in turn, the climate dictates where and how species can survive.

Life affects the composition of the atmosphere and therefore the climate because different life forms take in and release gases like carbon dioxide, methane and oxygen at different rates. Climatic conditions help to shape various ecosystems and habitats around the globe. A particular climate can be a boon to one species and a devastation to another. As the climate changes, species and ecosystems respond by adapting, migrating, or reducing their population. Gradual shifts in the climate are easier to adapt to than abrupt swings, and this is certainly true for humans as well as other species. Studies of Earth's climatic history indicate that climates have changed in the past and resulted in dramatic shifts in ecosystems. The most recent geological period the Holocene (about last 10,000 years), however, has been unusually stable.

There is a dynamic balance between life and climate

The manner in which the earth sustains life is of vital importance on many levels.

• The conditions on Earth such as temperature, moisture, oxygen concentration, and sunlight, are what sustain life.
• Throughout geologic history, life on Earth has affected the climate system and vice versa.
• Extinctions of species, both in the geologic past and in the present day, can be linked to changes in climate.
• Unraveling past climatic changes is key to understanding present and future shifts in the climate.
• Changes in climate will result in shifting ecosystems. It is not possible to predict the details of specific effects of climate change on each of the world's ecosystems.
• Although the concentrations of greenhouse gases have changed throughout Earth's history, there is no natural analog to today's rapid increases in human-created greenhouse gas emissions.

Helping students understand these ideas

Like much of climate science, these concepts span multiple scientific disciplines. Teaching these ideas is a way to illustrate how scientific thinking benefits from sharing expertise among different types of scientists.

This topic can be introduced by brainstorming for conditions that are needed for life to thrive. Students can explore how life exists in many parts of the earth system, such as in the depths of the oceans or in acidic hot springs. Life is robust and versatile. Nonetheless, all organisms need certain conditions to live.

The planet currently exists at a temperature that is neither boiling nor permanently frozen. This is due to the natural greenhouse effect that causes the atmosphere to retain outgoing heat. A possible misconception is to confuse the natural greenhouse effect with the enhancement of this effect caused by emissions of greenhouse gases from fossil fuel burning (McCaffrey & Buhr, 2008). This is an ideal opportunity to discuss the difference between natural processes and human effects. For example, if a certain amount of a greenhouse gas allows life on Earth to flourish, then is more of it better?

When teaching about the interplay between climate and life, the differences between natural and human caused changes should be emphasized. Questions may arise such as: Are all natural changes good? Are all human-caused effects bad? Is our current climate the "right" climate? It's important to emphasize that the recent increases in greenhouse gas concentrations in the atmosphere are unprecedented in the geologic past. Comparing natural and human-caused changes can foster stewardship of the planet among students.

Teaching about the limited ability of organisms to adapt to climate change should not lead to gloom-and-doom scenarios. Instead try to foster an understanding that humans have a responsibility to stabilize the natural climatic conditions in order to preserve the environments in which humans and the surrounding ecosystems thrive.

Bringing these ideas into your classroom

Many of these ideas are part of the life science curriculum but they integrate concepts from physical sciences, geography, and other disciplines. Possible topics to teach an understanding of this principle are:

• Seasonal migrations of species.
• The effects of the spring "green up" in the northern hemisphere and the resulting seesaw pattern in atmospheric CO2 concentrations as as illustrated by the Carbon Dioxide Exercise.
• Decade-scale events such as insect outbreaks, forest succession, or drought.
• The role of life to shape climate, particularly in the creation of Earth's oxygen-rich atmosphere.
• The 100,000 year cycle of ice ages, the role of CO2 in enhancing the temperature swings, and the response of biologic systems to these dramatic shifts in climate.
• Periodic mass extinction events that punctuate the geologic record and were likely related to climatic changes.

Another approach that may be engaging for older students is the delicate relationship between life and the climate. Many students will be surprised to learn of past mass extinction events and other sharp swings in the balance of the biosphere. This is a key place to discuss the role of humans in changing our environment and climate.

Teaching materials from the CLEAN collection

Middle school

• Temperature and precipitation as limiting factors in ecosystems - Students correlate graphs of vegetation vigor, temperature, and precipitation data for four diverse ecosystems to determine which climatic factor is limiting growth.
• The Ocean's Green Machines is a video about phytoplankton - the base of the marine food web, the source of half of the oxygen on Earth, and an important remover of CO2 from the atmosphere.
• Classroom experiments such as Uptake of Carbon Dioxide from Water by Plants can visibly show effects that are normally not observable. These demonstrations show the role of plants in mitigating the acidification caused when CO2 is dissolved in water.

High school

• Students can explore climate-driven ecosystem effects such as with an animation that shows Pine Bark Beetle Outbreaks and Climate. There are many resources about pine beetles in the CLEAN collection, including several videos.
• Why Fly South? How Climate Change Alters the Phenology of Plants and Animals will walk students through the process of plotting 30 years of data that shows the date of the first lilac bloom and the number of days of ice cover of nearby Gull Lake.
• The Once and Future Corals is a narrated slide show that illustrates how coral reefs are in danger from pollution, ocean temperature change, ocean acidification, and climate change. In addition, scientists discuss how taking cores from corals yields information on past changes in ocean temperature.
• Project Budburst is a citizen science project that looks at the impact of humans on plants and animals in the environment.

College 

Carbon Cycle - a brief explanation of the carbon cycle from NOAA.

Basics of the Carbon Cycle and the Greenhouse Effect provides a brief and easy to understand summary of the cutting edge research questions in this field.

CarbonTracker This NOAA tool is a CO2 measurement and modeling system to keep track of sources and sinks of carbon dioxide around the world.

xkcd Timeline of Earth's Average Temperature illustrates the stable climate throughout the Holocene.

Global Warming 55 million years ago, an article from the Smithsonian that summarizes the Paleocene-Eocene Thermal Maximum, which offers insights into our current climate conditions. This is an area of ongoing research, particularly because of its relevance to modern climate change.

Page 4

Climate changes for many reasons, and on many different time scales.

These key ideas illustrate the differences between weather and climate and unravel some of the processes that cause natural climate variability, and abrupt climate change, and human-caused climate change. Understanding climate variability such as the El Niño/Southern Oscillation is critically important in helping scientists tease apart natural variation from human-induced climate change. In this principle the human impact on the climate through burning of fossil fuels is clearly differentiated from naturally occurring climate processes.

These ideas help sort out different ways that climate can change

Students frequently conflate weather with climate. While related, weather occurs over short (hours to days) time scales, and climate occurs over seasons and longer time spans. Because of these common confusions, it is especially important to clarify topics such as:

• A spell of unusually cold or warm weather neither negates nor confirms human-caused climate change. Climate is defined as a long-term pattern with naturally occurring variability.
• The climate has changed throughout the history of Earth, to varying degrees, over different time periods and due to different causes.
• Human-caused warming is not the same thing as Earth's "natural" warming. Scientists use many lines of evidence to differentiate human-caused changes from natural cycles.
• Weather and climate can both vary to a large degree over very small distances.
  

Helping students understand these ideas

A helpful starting point is to establish the difference between weather and climate. Weather events occur over minutes to hours to weeks, while climate is a longer-term pattern that plays out over seasons, years and into millennia. Both can change abruptly, but the reasons for the changes are often very different.

Understanding natural climatic processes that drive multi-year cycles (like the El Niño/Southern Oscillation) requires an understanding of basic climatic patterns and processes as well as feedback effects. Once students can appreciate the complexity of the climate system they will be able to understand that global warming doesn't necessarily result in warming at every location but that some (few) places might experience a net cooling despite the global trend of rising temperatures. Likewise, the occurrence of brief periods of cooling during a long-term trend of warming does not negate the fact that the climate is indeed warming.

The single most common misconception in the public's understanding of climate change is that the climate has changed in the geologic past, which some people incorrectly extrapolate to mean that humans cannot affect the climate today. Regardless of a student's mastery of climate science in class, they are virtually guaranteed to encounter this misconception outside of class. Educators can be pro-active in developing a robust understanding of these concepts and reinforcing them with multiple types of learning activities.

• Many processes on Earth have more than one cause. Forest fires occur naturally, yet they also can be caused by arson. The presence of a natural cause does not negate the reality of a human trigger.
• Throughout geologic history, we know that more greenhouse gases in the atmosphere equates to a warmer climate, regardless of the source of the greenhouse gases (from the ocean, from wildfires, from volcanoes, from melting permafrost, etc.). So as humans add CO2 and other greenhouse gases to the atmosphere, we know that it also has the same warming effect. The physical process is the same either way.
• A key difference between past climate changes and today's climate change is the rate of change. Today's warming is much more rapid that past shifts in climate. This makes it harder for ecosystems to adapt.
• Read the Skeptical Science rebuttal of this misconception.

A related misconception is that humans cannot fix climate change. But if we know that the climate becomes warmer due to the addition of greenhouse gases, then we also know that adding less of them will reduce this effect. It is important to avoid a sense of hopelessness. These ideas are further discussed in Humans can take action, the guiding principle of climate literacy.

Bringing these ideas into your classroom

The two most basic cycles—the diurnal cycle and the annual cycle—are great places to begin exploring variability of weather and climate over time and space. Beyond these basic concepts, students can learn about climate variation on longer time scales, and how some changes are cyclic and others are not. These topics also afford the opportunity to present the key differences between weather and climate

It can be difficult to describe processes that operate on different time scales. Specific strategies that can help students understand this are using visualizations and teaching with simulations. Both of these approaches allow students to "observe" a process at work and get an overview of complex processes and relevant feedback loops.

A third concept that can enrich these ideas is to describe how scientific evidence can illuminate things that happened long ago. Scientific principles from geology, paleoclimatology, and atmospheric science have been used together to understand how climate systems have responded to changes on Earth in the past.

Teaching materials from the CLEAN collection

Middle school

High school

College

Find activities and visuals for teaching this topic

Search by grade level: middle school high school intro college upper college search all grade levels

References

What's Really Warming the World? - This animated graphic compares different forcings that are acting on Earth's climate. Climatic changes caused by orbital variation, the sun's luminosity, and volcanic emissions are compared with the effect of greenhouse emissions. The graphic is very engaging and the data is from NASA's Goddard Institute for Space Studies (GISS).

Climate Science Supplement from the 2014 National Climate Assessment report offers a thorough but readable explanation for both natural and human-caused changes in the climate system. Contains appealing diagrams that can be downloaded and reused for slides and handouts.

NASA Website about Difference between Weather and Climate - Summary written for a lay audience and supported by some NASA graphs.

NCAR Website about Difference between Weather and Climate- brief summary written for a lay audience.

The Biggest Control Knob: Carbon Dioxide in Earth's History by Richard Alley, presented at AGU in 2009, this video steps viewers through the geologic evidence for the role of CO2 in driving Earth's climate. Dr. Alley is an engaging and entertaining speaker.

What does past climate change tell us about global warming? This page from the Skeptical Science website provides clear answers to common questions and misunderstandings about climate change.

Page 5

When it comes to climate science, how do scientists know what they know? This aspect of climate literacy addresses the essential question of how we go about studying and understanding the climate system. Climate science follows the same methods and principles of all scientific research, and is based on asking questions, making observations, testing ideas, interpreting data, peer review, and communication of findings. The process of science has demonstrated its reliability over the course of hundreds of years, and it has brought benefits to all aspects of human society.

Because of its policy implications, climate science tends to be challenged more than other types of science. But that does not refute the overwhelming amount of scientific knowledge we have gained on this topic. Studies repeatedly show that climate researchers virtually all agree that human activities are altering the climate system. Nonetheless, some portion of the general public is under the impression that scientists are still debating whether or not humans are changing the climate. In fact, climate science is one of the most rigorous examples of scientific inquiry, practiced over several decades by scientists all over the world, and from multiple scientific disciplines. As this research expands our understanding, Its basic findings have remained unchanged since the late 1950s.

Science is a formal process, with built-in integrity

Many people do not know how science is actually conducted. A good starting place is to describe the iterative process of scientific research: from the collection of observations, review of prior research, analysis of data, modeling of various scenarios, and communication of findings, Because so few people know an active scientist (let alone a climate scientist), and many researchers do not communicate their research to non-technical audiences, it is important to help learners understand some of the basics of the work of climate scientists. These concepts are not unique to climate science; all areas of scientific research share common themes such as:

• Data is collected through a wide range of tools and techniques.
• Data is rigorously checked for quality and accuracy. When scientists use the term "uncertainty," they do not mean that they are unclear in their understanding. Uncertainty is a mathematical term that expresses a range of measured values, rather than one specific pinpoint.
• Models are a set of mathematical equations that are developed by measuring known processes that operate on Earth. Models are compared to actual observations in a process called calibration. Climate models can reproduce the same variations we see in today's climate, purely by using mathematics. Only once a model is well-calibrated is it used to project future changes in climate.
• The process of peer review allows for transparency in methods, results, analysis, and conclusions. Data is made available such that any analysis can be repeated by other researchers. Published work is scrutinized by others who are knowledgeable in the details of that topic. Scientists share data, methods, and results with other scientists.
• Peer reviewed publications are an important part of the scientific research process. Even though these articles are usually very technical and often hard to understand by a non-expert, they still serve as the primary way that climate science is communicated.
• Scientific agencies such as NOAA, NASA, and the US Geological Survey are public institutions that serve the citizens by studying the Earth.

Helping students understand these ideas

An area of common confusion that educators, students, and the public have is that climate scientists disagree as to whether or not climate change is happening, or if it is happening, whether or not humans are the primary cause. There are a variety of reasons for this, but the bottom line is the vast majority of scientists who study climate and publish in peer reviewed journals do agree that human activity is causing the planet to warm. A related area of confusion is that most people don't understand how climate scientists know what they know, which can make the findings harder to appreciate. This is partially because scientists aren't always good at communicating their research to non-technical audiences, and partially due to the way science is communicated in the media.

Another hurdle is the perception that understanding science is overly challenging. Here, educators can take active steps to engage students in science. Students will experience for themselves that science can be fun, intuitive to understand, and relevant to everyday life.

Bringing these ideas into your classroom

The best - and most fun - way to help students relate to the scientific process is to immerse them in it. The process of engaging in science can be accessible to all grade levels and can be brought into the classroom with a variety of approaches. There are countless relevant scientific questions to examine. Whether in teams or as individuals, learners can become immersed in the inquiry process of research, observations, data analysis, synthesis, and presentation that lies at the heart of all robust science.

• Make measurements of weather: temperature, rainfall, wind, snow, etc.
• Measure the temperature of different colored surfaces to explore albedo (the reflectiveness) of different materials.
• Use local meteorological data to answer questions.
• Compare local or measured data to other time periods or places.
• Measure energy use.
• Communicate findings to peers or the community.

Another tactic is for students to watch videos of engaging scientists at work. Climate scientists like Richard Alley (Earth: The Operators' Manual) and Katherine Hayhoe (Global Weirding) are masters of communicating climate science in an approachable, engaging style.

Teaching materials from the CLEAN collection

Middle school

• Using a Very, Very Simple Climate Model in the Classroom - Through a simple online model, students learn about the relationship between these and learn about climate modeling while predicting temperature change over the 21st century.
• In the Global Climate Change and Sea Level Rise activity, students will practice the steps involved in a scientific investigation as they learn why ice formations on land (and not those on water) will cause a rise in sea level upon melting.
• Evidence of Ice-Free Seas and Reading Antarctica's Rock Cores are fun, hands-on activities where students make sediment cores and learn about past climate history.
• GLOBE Observer is a citizen science project that helps scientists to look at the changes in clouds, water, plants, and other life. There is an app that allows anyone to report observations in five key areas.

High school

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References

Observed Climate Change from the 2014 National Climate Assessment: "Global climate is changing and this change is apparent across a wide range of observations. The global warming of the past 50 years is primarily due to human activities." Contains excellent, downloadable graphics.

NOAA's Climate Dashboard (on the bottom half of this page) displays 12 different datasets of climate change, including atmospheric CO2, sea level, snow cover and glacier size.

NASA Vital Signs - Scroll through the tabs to view current data for CO2, global temperature, Arctic sea ice minimum, ice sheets, and sea level.

The Real Process of Science is an updated, realistic replacement for the cookbook-style "scientific method." This interactive graphic from Berkeley highlights the cyclic process of scientific inquiry and advancement.

Process of Science - This web resource from VisionLearning contains 16 modules describing various aspects of scientific inquiry, data analysis, peer review, ethics and more.

Scientific Consensus: Earth's Climate is Warming - from NASA, with a list of scientific statements from agencies in the U.S. and abroad.

The 97% consensus on global warming from Skeptical Science offers a summary of research that measures the amount of agreement in the climate science community.

Examining the Scientific Consensus on Climate Change, P. Doran, M. Zimmerman. EOS, Transactions American Geophysical Union, 2009, vol. 90, no. 3, p. 22, 200. This article compares the consensus views of scientists and the general public on climate change.

RealClimate - Read real-time discussions of emerging climate science and policy, written by climate scientists.

Page 6

The potential for human activities to increase the temperature of the Earth through greenhouse gas emissions has been described and calculated for over a century. Volumes of scientific research across multiple scientific disciplines agree that humans are warming the climate, and the 2013 IPCC Fourth Assessment Report states, "Human influence on the climate system is clear. This is evident from the increasing greenhouse gas concentrations in the atmosphere, positive radiative forcing, observed warming, and understanding of the climate system." (From the IPCC AR5)

There is overwhelming evidence that human activities, especially burning fossil fuels, are leading to increased levels of carbon dioxide and other greenhouse gases in the atmosphere, which in turn amplify the natural greenhouse effect, causing the temperature of the Earth's atmosphere, ocean, and land surface to increase. That greenhouse gases "trap" infrared heat is well established through laboratory experiments going back to 1856 when Eunice Foote first measured the effect.

The well-documented trend of increasing of CO2 in the atmosphere is caused by the burning of fossil fuels and massive land cover changes. The "smoking gun" that shows clearly that human activities are responsible for recent increases in carbon dioxide in the atmosphere is provided by carbon isotopes (carbon atoms of different atomic weight). These isotopes allow scientists to "fingerprint" the source of the carbon dioxide molecules, which reveal that the increased CO2 in the atmosphere is caused by fossil fuel burning (see references).

The human causes of climate change are some of the most important concepts to teach

Due to the basic physics of heat-trapping gases and an exponential rise in population and energy consumption, humans have become a force of nature. Clearly, this is a topic with enormous political, socio-economic and emotional dimensions, but the scientific results show clearly that:

• Human activities, particularly the combustion of fossil fuels, are altering the climate system.
• Human-driven changes in land use and land cover such as deforestation, urbanization, and shifts in vegetation patterns also alter the climate, resulting in changes to the reflectivity of the Earth surface (albedo), emissions from burning forests, urban heat island effects and changes in the natural water cycle.
• Because the primary cause of recent global climate change is human, the solutions are also within the human domain.
• Because we understand the causes of climate change, that paves the way for effective solutions to be developed and deployed. (Learn more about teaching about solutions.)
  

Helping students understand these ideas

The human impact on climate change is the most frequently misunderstood aspect of climate science. Some sectors of the public continue to debate whether these ideas can be true, despite the well-established science. There are several possible reasons why students may resist the conclusion that humans are altering the climate. This concept may be uncomfortable to students due to feelings of guilt, political resistance, or genuine lack of scientific understanding. Furthermore, projections of the effects of climate change on our society can frighten, overwhelm, or discourage students. This can result in denial or resistance to learning. Furthermore, even if a student possesses a firm grasp of this topic, it is nearly certain that at some point this knowledge will be challenged outside of class. Building a solid and careful scientific argument is essential.

Educators are encouraged to introduce this topic with generous scaffolding that establishes the foundations of the process of science, the underlying principles of climate science, and a reliance on the robust scientific research that supports this conclusion. Several strategies are presented on this page about Teaching Controversial Environmental Issues which emphasizes the affective and emotional aspects of student learning.

It may be tempting to have a debate about this topic, but that may not be the most effective way to characterize it. A debate suggests that there are two credible, opposing viewpoints, when in fact the scientific community is virtually unanimous about the human causes of climate change. Secondly, debating a topic can reinforce misconceptions and cause unnecessary controversy in the classroom. That said, careful discussion of diverse viewpoints is absolutely essential. Role playing can be one way to represent broad perspectives, while maintaining scientific accuracy.

Bringing these ideas into your classroom

Even though this topic can be a sensitive one, it is also an essential facet to understanding climate change. Educators are urged not to shy away from the human role in shaping the climate, but instead to approach it in a deliberate manner, with pacing and framing intentionally designed to help your students understand the science and reconcile the meaning.

• When possible, use data-driven explanations.
• Avoid assigning blame or judgement. As atmospheric scientist Scott Denning puts it, CO2 traps heat "because of its molecular structure, not because capitalism is evil. It's just bad luck!" (Scott Denning Research Group, ppt for Engaging Hostile Audiences)
• Weave solutions into the discussion every step of the way. This prevents feelings of hopelessness and also shows the scientific and technical responses that are needed to curb the worst effects of climate change.
• Foster a classroom environment where all perspectives are welcome. Invite students to voice their doubts, fears, or uncertainties. (Learn more about creating a validating classroom environment.)

Teaching materials from the CLEAN collection

Middle school

High school

Related Pedagogic Methods:

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7. Climate Change has Consequences

Most people are aware of the increasing frequency of extreme weather events, which is what climate scientists predicted for a warming world. The impacts of climate change on humans and environmental systems have become a focus for resource managers, medical professionals, emergency managers, insurance companies, and military planners. A great challenge of the 21st century will be to prepare communities to adapt to climate change while reducing human impacts on the climate system (known as mitigation). Additional factors such as poverty, a lack of resources, the absence of political will, and the necessity for nations to work together add further complexity to this challenge. Many jobs and industries will be affected by the changes that are happening or are anticipated for the future.

Climate change has profound impacts at home and afar, today and in the future

The importance of this principle is readily apparent: our climate is changing and so is our world. Symptoms of climate change are all around us: extreme weather, diminishing sea ice, year after year of record-breaking warmth, drought, fires, and stress to ecosystems. Many of these consequences will create hardship for humans. Some key points are:

• The impacts of human-caused climate change are already being seen, from polar regions, to our backyards, to communities around the world.
• Consequences of climate change will affect the biosphere on many levels, from coral bleaching, to dying forests, to species extinction.
• Human infrastructure is threatened by a changing climate, such as encroachment of coastlines, stress to the energy grid, and shifting structures as a result of melting permafrost.
• A warming climate threatens mountain snowpacks, fresh water supplies, and hydropower that serve millions of people.
• Changes in climate and precipitation patterns are impacting agriculture and food security.
• Populations that are already vulnerable in terms of sea level rise and food security are poised for the greatest hardships. Political unrest, migration of refugees, and global economic impacts are all visible outcomes. Some of these effects are already evident.

Helping students understand these ideas

Educators know that linking classroom topics to relevant news is a powerful way to engage students. The impacts of climate change are all too easy to find, but nonetheless using a local example is an effective way to draw students into the topic and help them unravel the science.

Keep in mind that alarming students and the public about the impact of climate hazards, such as droughts and extreme events, can be counter-productive and cause people to ignore the warnings, feel hopeless, or succumb to denial. However, glossing over the severity of the impacts and the enormous social and environmental ramifications of climate change can lead to a society that is ill-prepared to deal with change. Finding a balanced approach and avoiding a "despair deficit" is clearly a good practice, both inside and outside of the classroom.

Another challenge for fostering public awareness for the consequences of climate change is that many of the effects are far away and may not directly touch the lives of our students in an obvious way. Two solutions to this are to use local data and examples to examine climate changes that affect your region, or to employ a case study approach that will allow students to gain a deeper sense of how these impacts will profoundly affect people and ecosystems in faraway areas.

Bringing these ideas into your classroom

Here are a few pedagogic strategies for teaching about climate impacts.

• Because climate change affects so many parts of our lives, the theme can be woven into a range of topics throughout a course or a unit. Subjects such as history, economics, or health can all touch on climate change. Climate impacts needn't only be addressed within the specific context of an earth science class.
• Student teams can investigate climate impacts on different parts of the earth system. Teams could learn how climate is affecting the cryosphere, coral reefs, birds, forests, native peoples, agriculture, transportation, diseases, national security, and many other avenues.
• A geographic approach could be used to examine impacts in different parts of the world.
• Students could write or read narrative stories about how climate affects people.
• Students could use imaginary time travel to visit the climate of the future, which would vary depending on actions we take today.
• Students could use local climate data such as temperature, snowfall, and streamflow. Similarly, students could learn about economic impacts such as maple syrup production, crop yields, and winter recreation.
• Role-playing activities could be used to explore how the climate affects people in different walks of life such as farmers, construction workers, insurance agents, or pilots.

Integrating Solutions

When teaching about climate impacts, it's also a good idea to touch on solutions to climate change. Ideally, students can feel informed and empowered, rather than discouraged about the world's problems. Some possibilities include:

• Draw on case studies showing successful emissions reduction strategies.
• Explore adaptation strategies for humans, plants, and animals.
• Create an atmosphere of creativity and problem-solving as we all strive to meet this grand challenge.
• These ideas are discussed more fully on the next page, Humans can take action to reduce climate change and its impacts.

Teaching materials from the CLEAN collection

These concepts are well-represented in the CLEAN resources. One way to narrow the search is to look for a specific type of impact like melting ice and permafrost, sea-level rise, extreme weather, or impacts to plants and animals. Alternatively, you can search by regions, like the US Southwest or US coastal areas.

Despite the best efforts of the CLEAN team to keep our teaching materials up-to-date, impacts to the climate system are changing rapidly. Be sure to seek up-to-date graphics and data to supplement some of these activities.

Middle school

• Loss of Arctic sea ice has been making a lot of headlines. The Ch-Ch-Ch-Changes lesson plan allows students to analyze and explore this topic with graphing and hands-on activities.
• What if the Ice Shelves Melted? - This hands-on lesson from ANDRILL involves making a model of Antarctica and then using their model to explore the impact of potential ice shelf melting and break-up.
• Investigating Coral Bleaching Using Real Data - This sequence of 5 activities uses real-world data to understand how scientists monitor coral bleaching events.
• Ten Signs of a Warming World is an interactive website that provides descriptive information and data related to ten compelling climate indicators.

High school

College

Find activities and visuals for teaching this topic

Search by grade level: middle school high school intro college upper college search all grade levels

Fourth National Climate Assessment Report - Published in 2018, this report focuses on the impacts of climate change. This is an ideal "one-stop-shop" for information, data, and reusable graphics on the effects of climate change.

2014 National Climate Assessment Report summarizes the impacts of climate change on the United States, now and in the future. The report can be explored by region and uses clear, simple messages to streamline the findings.

The Effects of Climate Change from NASA - Short explanations of the major effects of climate change, with links to a deeper dive.

How Much is Sea Level Rising? - This page from the Skeptical Science website provides clear answers to common questions and misunderstandings about climate change.

Arctic Climate Impact Assessment from the Union of Concerned Scientists, this article describes observed climatic changes as well as predicted impacts. Topics include sea ice, ecosystems, albedo and sea level rise.

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