All About Digital Earth Watch—Part II: Engaging Learners—Chapter 9
integrative teaching about scientific concepts
Global Systems Science (GSS) is part of the Digital Earth Watch team and serves as a prime example of how DEW tools and techniques can be applied in formal education curricula. GSS is an integrated, interdisciplinary course with a target audience encompassing the entire range of high school students from grades nine through twelve. It emphasizes how scientists from a wide variety of fields work together to understand significant problems of global impact. GSS stresses the “big ideas” of science, such as the concept of an interacting system, the coevolution of the atmosphere and life, the goal of a sustainable world, and the important role that individuals play in both impacting and protecting our vulnerable global environment.
introduces all of the other books in the Global Systems Science series, and presents four key ideas that thread through the entire course: First, the Earth has tremendously diverse environments, yet it is a single planet that we all call “home.” Second, we can better understand the Earth if we think of it in terms of systems. Third, everything is connected to everything else. And fourth, the goal of global studies is to find out what we can do to sustain life on Planet Earth—now and in the generations to come. To learn about the value of laboratory work for investigating Earth systems, students design and conduct controlled experiments to determine how to sustain life inside a terrarium. They also begin using the Digital Earth Watch software in two investigations:
ABCs of Digital Earth Watch Software
although not an exhaustive work incorporating all features of DEW software, this book is a great introduction for students to get started in the use of digital image analysis software. Students use the software "ColorBasics" to explore the basics of light and color, how color can be analyzed as combinations of three primary colors. They use "DigitalImageBasics" software to learn the fundamentals of digital images: pixels, measuring length and area. The most advanced software is "AnalyzingDigitalImages" that has tools for students to measure light, color and to finally analyze satellite images in terms of both color and temporal changes.
The next three books in the GSS series are concerned with key environmental problems which affect the entire planet—climate change, depletion of the world’s ozone layer, and loss of biological species. These issues are included in the GSS curriculum because they are clearly global in nature, each represents a potential threat to life and prosperity on planet Earth, and each illuminates important aspects of the interaction between human activities and Earth systems.
addresses the once controversial question of how human activities may be changing Earth’s climate. It takes students on a “field trip” to Mauna Loa Observatory where they see how scientists have measured carbon dioxide in the Earth’s atmosphere since 1957. They graph and interpret data from Mauna Loa and other observatories which led to the prediction, in 1988, that atmospheric changes will cause the entire globe to gradually warm up.
Students also measure carbon dioxide in the laboratory to find out how much is contained in various samples: classroom air, human breath, pure CO2, and car exhaust.
The book goes on to show how some scientists challenged the discoveries at Mauna Loa the early 1990’s, and the consensus of opinion about global climate change that finally emerged. The book identifies scientific questions that remain unanswered, and involves students in thinking about the economic, political, and ethical implications of regulating human activities to reduce the likelihood of global climate change.
In the context of this book, students may use DEW software with data sources such as
MyNASAdata, climate.nasa.gov, and EOS-Webster.
is a success story about how people around the globe are cooperating to solve a serious environmental problem. Ozone gas in the upper atmosphere shields our planet from ultraviolet sunlight that is thought to cause skin cancer and cataracts in humans, and may be harmful to a wide variety of plants and animals. The story of how the scientific world came recognize the depletion of ozone and discovered the connection with production of certain chemicals used in refrigerators, air conditioners, and the computer industry demonstrates that science can be an exciting and adventuresome field, and that people in a wide variety of careers often play important roles in scientific discoveries.
The fascinating epilogue, in which more than 100 countries agreed to phase out the ozone-destroying chemicals, clearly shows the connection between science and social action. Since ozone will continue to be depleted for several decades due to chemicals already in the atmosphere, students learn how to protect themselves by monitoring the levels of UV radiation in their community, and experimenting with Sun block to see if it really offers protection from the ultraviolet rays of the Sun.
There is an investigation "The Effect of Increased UV on Plants" which
lends itself well to the use of DEW software in analysis of plant health by color analysis.
In the investigation "Ozone Monitoring," data from ozone-monitoring satellites are used, and a great enhancement of the investigation is to get such data from the source, as well as ozone maps, and do analyses with AnalyzingDigitalImages software.
is about the endangerment and extinction of entire species of plants and animals throughout the world due to human actions, beginning with the case study of the buffalo.
Students learn about the value of biodiversity, from the discovery of new medicines and materials, to the protection of food crops and global systems. Students put into perspective the current loss of biodiversity through laboratory work on how species can adapt to changing conditions, theories about how new species evolve, and studies concerning the natural causes of extinctions. Further laboratory work illustrates the vital importance and fragility of soil in supporting entire communities of plants and animals; and how soil productivity is impacted by certain agricultural practices.
Finally, students consider the history of actions that people around the world have taken to protect endangered species, up to current debates in Congress, and international agreements to preserve biodiversity.
Digital Earth Watch is relevant to this subject area in the realm of loss of biodiversity of plant life. The essential theme of DEW as measuring vegetation health is intrinsically valuable in studies of loss of plant biodiversity.
Some of the student books put global environmental problems into context by focusing on the natural systems within which human activities occur. Such understanding is essential if we are to grapple with key global problems, and eventually find ways for humans to prosper and thrive without diminishing the rich diversity of life on Planet Earth.
Life and Climate
is about how our atmosphere and climate came to be as they are today, how life on Earth evolved, and how the evolution of life and climate have affected each other since the Earth was formed. Students find the story of how tiny plants brought oxygen to the Earth’s atmosphere and how changing climates may have brought about the evolution of our human ancestors in Africa five million years ago. They construct timelines and place milestones in the development of life. They learn about the gradual acceptance of tectonic plate theory, and how the movement of tectonic plates is affect climate changes that in turn affect the evolution of life. In the laboratory, students experiment with dissolving rocks to explore the long term carbon cycle which has contributed to the long term stability of the Earth’s climate. In the final chapter, they consider what the Earth’s past can tell us about its future.
Particularly relevant to this book is the DEW investigation What's Been in Your Backyard over the Past Centuries?
is about the interdependence of all living things and the nonliving environment. It is also about how human activities are changing ecosystems around the world. Through case studies students learn about the vastly different kinds of ecosystems, or biomes, on our planet. They discover that humans have been changing ecosystems for thousands of years; but that the pace of change has increased with the rapid growth of human populations in the last century. In the laboratory, students investigate the variables that are important in the process of decomposition, and relate their findings to the biogeochemical cycles that maintain Earth’s biosphere.
Through interviews, they “meet” scientists like Samira Omar of Kuwait, studying the ecological effects of the Gulf War; and Dr. Dagmar Werner, working to preserve the biodiversity of the rain forests of Central America. They will also find out what people in the United States are doing to reduce human impact on ecosystems, and consider ways that their own actions can make a difference.
Biome maps are great for analysis with AnalyzingDigitalImages sofware.
is about the way energy flows through the atmosphere, oceans, land, and living things. Analyzing the flow of energy is a very useful way to understand Earth systems. For example, through laboratory investigations, students explore the process of convection, and see how to use this process to understand earthquakes and volcanoes, global winds, and ocean currents. In other lab activities they experiment with the variables that affect water flowing through a bottle, and then apply their insights about dynamic equilibrium to understanding how the greenhouse effect is expected to change the Earth’s climate. In the last chapter your students learn about how some of the energy that flows through living systems has been stored, over millions of years, in the form of fossil fuels; and how all that stored energy is being released to power civilization for only a few short decades. With this background, your students are asked to think about how the flow of energy through Earth systems affects their daily lives, and how life might be different for their children and grandchildren.
AnalyzingDigitalImages software can be very useful in studies pertinent to this book, with satellite images of ocean properties, weather, cloud cover, ice cover, and of course vegetation. In the chapter on volcanoes, there is opportunity to do analyses of vegetation changes associated with the eruption of Mt St. Helens.
GSS is concerned not only with identifying problems, but arriving at solutions. Two aspects of our modern age stand out as possibly the most important underlying causes of global environmental change—the rapidly growing human population, and the ways in which people use natural resources for energy. Yet within both areas there is reason to hope that intelligent decisions by individuals can reduce the impact of these problems and lead to a habitable world for future generations.
begins by inviting students to take an inventory of the ways that they use electricity. By “following the wires” back to a power plant, and from there to a grid of all power plants in the country, students begin to grasp the vast infrastructure that supports our way of life. Through laboratory experiments they learn the basic principles on which electrical devices work; and through a brief history, they learn how our national energy policy came to be. They also learn about the huge amounts of Earth materials that are used for transportation, home heating, and industry on a daily basis, and the small fraction of that energy that is actually put to use. In the last portion of the unit, students conduct simple experiments in which they discover that conservation will allow us to maintain our current levels of energy usage while saving billions of dollars and reducing our impact on the environment. They also explore new technologies for satisfying the energy needs of a growing human population while keeping the impact of energy use to a minimum.
This book is rich with opportunities for digital image analysis, from maps of solar illumination for suitability of solar energy use to maps of fossil fuel resources.
addresses a fundamental problem: even if we can change our habits to use only clean and efficient sources of energy such as solar, wind, and water power, global environmental problems will continue to worsen if the world’s population continues to grow at the present rate. Today (2009) there are nearly 7 billion people on Earth, and the population increases by about one million every four days. Yet it is difficult for students to see the effects of population growth. They are therefore asked to think about the quality of their own lives as a starting point, and to recognize how satisfying their needs takes a share of the Earth’s resources. By comparing their own lives with conditions in countries such as China and India, they will be in a better position to consider what may happen if the human population continues to grow as rapidly as it is today. Through mathematical investigations, students learn about factors that contribute to the rate of population growth, and the idea of carrying capacity, which relates an ecosystem to the populations it can sustain. The cultural and religious dimensions of efforts to curb population growth are sensitively discussed, and students are encouraged to form their own opinions about what can and should be done by individuals and by governments to control the growth of the global human population.
To round out the series, and make the GSS course suitable as an Earth Science sequence, the subject of astronomy is central to two of the books.
A Changing Cosmos
is the best of material derived from the Hands-On Universe (HOU) project and builds on Solar System Science with more advanced use of Image Processing Software in a series of investigations:
Finding Features—a Browser's Guide to the Universe;
Measuring Size—using "pixel plate scale" of telescope images to measure sizes of things such as a lunar crater or orbits of Jupiter's moons;
Measuring Color—colors of stars, the HR diagram, and how stars evolve according to their mass;
Measuring Distance—how the cosmological distance ladder is used to determine the distance to far away objects, including how Cepheid Variable stars are used to measure distances to galaxies;
Measuring Brightness—photometry; and
Searching for Supernovae—how astronomers find supernovae—exploding stars.
This book stays within the overall GSS theme by dealing with the question of cosmic catastrophes that can affect Earth and especially the danger of asteroid impact and its effects on life.
GSS embraces the technology developed for Digital Earth Watch, and puts it to work in a carefully developed curriculum first through guided investigations illuminating key societal problems we are facing, and then ideally, students are in a position to design their own investigations using DEW tools to explore new questions that they arrive at themselves.
Solar System Science
(formerly Hands-On Solar System) lets students load images from professional telescopes into image processing software developed for use in the classroom, and learn key concepts in astronomy, mathematics, and technology. Solar System Science blends content learning with critical thinking skills and processes such as data interpretation, measurement techniques, and using appropriate tools for exploration.