Unit 4: Considering the Influence of Light and Thermal Phenomena on Global Climate
A. Learning more about disciplinary core ideas articulated in the US Next Generation Science Standards
The US Next Generation Standards (NGSS Lead States, 2013) includes disciplinary core ideas about global climate change that students should learn by the end of middle school: Human activities affect global warming. Decisions to reduce the impact of global warming depend on understanding climate science, engineering capabilities, and social dynamics.
Question 4.18 What relevant US NGSS disciplinary core ideas have you used in considering the influence of light and thermal phenomena on global climate change?
The US Next Generation Science Standards suggests disciplinary core ideas for teaching science topics in grades K-2, 3-5, 6-8, and 9-12. These learning progressions suggest ways to build disciplinary knowledge throughout schooling. (See: https://www.nextgenscience.org/sites/default/files/resource/files/AppendixE-ProgressionswithinNGSS-061617.pdf )
Table IV.5 presents the learning progressions articulated for teaching about disciplinary core ideas related to global climate change. Relevant topics in physical science include electromagnetic radiation, conservation of energy and energy transfer. Relevant topics in earth and space sciences include weather and climate, and global climate change. This course addresses the bolded disciplinary core ideas stated in each grade band.
|TABLE IV.5 NGSS disciplinary core ideas relevant to teaching about global climate change|
|PS4.B Electromagnetic radiation||Objects can be seen only when light is available to illuminate them.
|Objects can be seen when light reflected from their surface enters our eyes.
|The construct of a wave is used to model how light interacts with objects.
|Both an electromagnetic wave model and a photon model explain features of electromagnetic radiation broadly and describe common applications of electromagnetic radiation.|
|PS3.A Definitions of energy
|Moving objects contain energy. The faster the object moves, the more energy it has. Energy can be moved from place to place by moving objects, or through sound, light, or electrical currents. Energy can be converted from one form to another form.||Kinetic energy can be distinguished from the various forms of potential energy. Energy changes to and from each type can be tracked through physical or chemical interactions. The relationship between the temperature and the total energy of a system depends on the types, states, and amounts of matter.||The total energy within a system is conserved. Energy transfer within and between systems can be described and predicted in terms of energy associated with the motion or configuration of particles (objects).
Systems move toward stable states.
|PS3.B Conservation of energy and energy transfer
|Sunlight warms Earth’s surface.|
|Learning Progressions for Earth and Space Science|
|ESS2.D Weather and climate
|Weather is the combination of sunlight, wind, snow or rain, and temperature in a particular region and time. People record weather patterns over time.
|Climate describes patterns of typical weather conditions over different scales and variations. Historical weather patterns can be analyzed.
|Complex interactions determine local weather patterns and influence climate, including the role of the ocean.
|The role of radiation from the sun and its interactions with the atmosphere, ocean, and land are the foundation for the global climate system. Global climate models are used to predict future changes, including changes influenced by human behavior and natural factors.|
|ESS3.D Global climate change||See PS3.B:
Sunlight warms Earth’s surface
|See PS3.B: Energy can be moved from place to place by … light... Energy can be converted from one form to another form.||Human activities affect global warming. Decisions to reduce the impact of global warming depend on understanding climate science, engineering capabilities, and social dynamics.||Global climate models used to predict changes continue to be improved, although discoveries about the global climate system are ongoing and continually needed|
|• Bolded statements are addressed in this course.|
- Discuss with your group members ways in which you have used some aspects of the disciplinary core ideas that are relevant to teaching about global climate change.
- Select one of these disciplinary core ideas that has been the most interesting for you during this course and discuss how and what you have learned. Also include in your discussion at least one NGSS science and engineering practice and at least one crosscutting concept that you used while learning about this disciplinary core idea.
- [As discussed in NGSS Appendix F, science and engineering practices include asking questions (for science) and defining problems (engineering), developing and using models, planning and carrying out investigations, analyzing and interpreting data, using mathematics and computational thinking, constructing explanations (for science) and designing solutions (for engineering), engaging in argument from evidence, and obtaining, evaluating, and communicating information. As discussed in NGSS Appendix G, cross cutting concepts include patterns, cause and effect: mechanism and explanation, scale, proportion, and quantity, systems and system models, energy and matter: flows, cycles, and conservation, structure and function, and stability and change ( https://www.nextgenscience.org/resources/ngss-appendices ).]
B. Reflecting upon this exploration of the science underlying claims of global climate change
This unit began by developing understandings about the nature of light from the Sun, both of the colorful spectrum we can see and of a much larger electromagnetic spectrum not visible to our eyes. Students learned about infrared radiation and its role in the greenhouse effect, which is a natural phenomenon that generates the warm atmosphere surrounding the surface of the Earth. Students also examined evidence for the recent increase in the average global temperature of that atmosphere, the impact of that increase in average global temperature on rising sea levels, and ways that individuals, communities, states, nations, and international organizations are taking action to address global climate change issues.
Scientists base claims about global climate change on evidence. They report their studies in peer-reviewed articles that describe in detail the questions they are asking, why these questions are of interest, what already is known about these issues, how they design their investigations, what results they obtain, and what the implications are of those findings. Since 1988, the Intergovernmental Panel on Climate Change (IPCC) has provided a way for scientists all over the world to collaborate in assembling and assessing such evidence in order to provide the public and policy makers with the best information possible on which to base decisions.
C. Making connections to NGSS understandings about the nature of science
The Next Generation Science Standards articulates eight understandings that students should learn about the nature of science in Appendix H ( https://www.nextgenscience.org/resources/ngss-appendices ).
Scientific investigations use a variety of methods. As discussed in section IV.B, for example, studies of glaciers have ranged from ‘on the ground’ vivid video recordings of glacial calving events in Greenland, such as the Chasing Ice documentary, to complex analyses of data from satellites monitoring the acceleration of Antarctica’s glaciers flowing toward the ocean.
Scientific knowledge is based on empirical evidence. As discussed in section V.A.3, for example, scientists collaborating through the Intergovernmental Panel on Climate Change have provided policy makers with a series of graphs showing the increase in mean global temperature, increase in sea levels, increase in concentrations of greenhouse gases in the atmosphere, and increase in emissions of carbon dioxide from human activities from 1850 to recent times.
Scientific knowledge is open to revision in light of new evidence. As discussed in sections III.A, 2 and 3, development of knowledge about light from the Sun is a good example of this aspect of the nature of science. When Isaac Newton was exploring the nature of light from the Sun in the late 1600’s and early 1700’s, he used a prism to disperse light into its component colors and developed an explanation of rainbows. His knowledge and explorations about light were limited to light that human eyes can detect. William Herschel started with that perspective, exploring the heating effects of different colors of the spectrum produced by shining sunlight through a prism. In 1800, he reported that a thermometer placed outside the red end of the spectrum also warmed; he attributed this to “invisible rays from the sun” that were “invested with a high power of heating bodies, but with none of illuminating objects.” Scientists have now observed that energy coming to Earth from the Sun in this form of infrared radiation is almost as much as the energy in light visible to human eyes. In 1801, Wilhem Ritter discovered ultraviolet radiation from the Sun, invisible radiation beyond the violet part of the spectrum. Over the next 100 years, scientists from many different countries contributed to new knowledge about these invisible forms of light. The spectrum now ranges from very large radio waves to tiny gamma rays with “visible light that human eyes can see” being only a very small region of the entire electromagnetic spectrum.
Science models, laws, mechanisms and theories explain natural phenomena. As discussed in section IV.B, for example, the natural greenhouse effect is an explanatory model of what happens when light from the Sun shines on the Earth. As shown in Fig. 4.15, some of the light from the Sun is immediately reflected back to space; some is absorbed and warms the surface of the Earth; some gets emitted back out into the atmosphere as infrared radiation and travels on out to space; some, however, is absorbed by greenhouse gases instead and then re-emitted, with some of that infrared radiation traveling back toward the surface of the Earth. The greenhouse effect explains a natural phenomenon, the warming of our atmosphere. If more energy from the Sun enters than leaves the Earth, however, the global mean temperature will continue to increase.
Science is a way of knowing. As discussed in section V.A.3, the reports produced by the many scientists participating in the Intergovernmental Panel on Climate Change (IPCC) are examples that science knowledge is cumulative and many people from many generations and nations have contributed to science knowledge. As noted above, the IPCC Fifth Assessment’s section on The Physical Science Basis included 1409 pages prepared by Working Group 1 (https://www.ipcc.ch/report/ar5/wg1/). This working group included a team of 209 coordinating-lead authors and lead authors, 50 review editors, and more than 600 contributing authors from all over the world. Their work was reviewed by 1089 expert reviewers and 38 governments. The result was a detailed presentation of the consensus about evidence that underlies claims made about climate change by scientists from around the world. Scientists are now working on the IPCC Sixth Assessment, with updated information published in 2021 about the physical science basis of claims about global climate change ( https://www.ipcc.ch/assessment-report/ar6/ ).
Scientific knowledge assumes an order and consistency in natural systems. In particular, by the end of middle school, students should understand that science assumes that objects and events in natural systems occur in coherent patterns that are understandable through measurement and observation. As shown in Fig. 4.20, for example, observation of local mean temperatures all over the world have been combined to show global patterns in the changes in temperature from 1880 to the present, with the past five years being the warmest of the last 140 years. As shown in Fig. 4.51, for example, the World Glacier Monitoring Service is comparing the cumulative mass of ice change in glaciers all over the world based on measurements from 1950 to the present in an effort to identify patterns in what is happening to melting glaciers as the mean global temperature rises.
Science is a human endeavor. The Intergovernmental Panel on Climate Change is an example of the way that scientists all over the world are collaborating with one another to collect and analyze data that provide evidence on which to base understandings about what is happening to the Earth’s climate. The IPCC reports demonstrate that men and women from different social, cultural, and ethnic backgrounds work as scientists and engineers as well as that scientists and engineers rely on human qualities such as persistence, precision, reasoning, logic, imagination and creativity.
Science addresses questions about the natural and material world. By the end of middle school, students should understand that science limits its explanations to systems that lend themselves to observation and empirical evidence. As implied in section VIII, other aspects of human endeavor also are necessary for individuals, communities, states, nations, and international organizations to take action to address the climate change already underway and predicted for the future. Examples include individuals committing to live more sustainably based on analyzing their own carbon footprints, military experts publicly advocating for ways to prepare for a crisis denied by many, and government officials undertaking unpopular measures to reduce emissions. Such actions embodying the human qualities of commitment and courage as well as curiosity can inspire hope for the future of our planet.