- The Sun is the primary source of energy for Earth's climate system.
- Sunlight reaching the Earth can heat the land, ocean, and atmosphere. Some of that sunlight is reflected back to space by the surface, clouds, or ice. Much of the sunlight that reaches Earth is absorbed and warms the planet.
- When Earth emits the same amount of energy as it absorbs, its energy budget is in balance, and its average temperature remains stable.
- Climate is regulated by complex interactions among components of the Earth system.
- Earth's climate is influenced by interactions involving the Sun, ocean, atmosphere, clouds, ice, land, and life. Climate varies by region as a result of local differences in these interactions.
- The interconnectedness of Earth's systems means that a significant change in any one component of the climate system can influence the equilibrium of the entire Earth system. Positive feedback loops can amplify these effects and trigger abrupt changes in the climate system. These complex interactions may result in climate change that is more rapid and on a larger scale than projected by current climate models.
- Life on Earth depends on, is shaped by, and affects climate.
- Life—including microbes, plants, and animals and humans—is a major driver of the global carbon cycle and can influence global climate by modifying the chemical makeup of the atmosphere. The geologic record shows that life has significantly altered the atmosphere during Earth's history.
- Our understanding of the climate system is improved through observations, theoretical studies, and modeling.
- The components and processes of Earth's climate system are subject to the same physical laws as the rest of the Universe. Therefore, the behavior of the climate system can be understood and predicted through careful, systematic study.
- Environmental observations are the foundation for understanding the climate system. From the bottom of the ocean to the surface of the Sun, instruments on weather stations, buoys, satellites, and other platforms collect climate data. To learn about past climates, scientists use natural records, such as tree rings, ice cores, and sedimentary layers. Historical observations, such as native knowledge and personal journals, also document past climate change.
- Human activities are impacting the climate system.
- The overwhelming consensus of scientific studies on climate indicates that most of the observed increase in global average temperatures since the latter part of the 20th century is very likely due to human activities, primarily from increases in greenhouse gas concentrations resulting from the burning of fossil fuels.
- Climate change will have consequences for the Earth system and human lives.
- Melting of ice sheets and glaciers, combined with the thermal expansion of seawater as the oceans warm, is causing sea level to rise. Seawater is beginning to move onto low-lying land and to contaminate coastal fresh water sources and beginning to submerge coastal facilities and barrier islands. Sea-level rise increases the risk of damage to homes and buildings from storm surges such as those that accompany hurricanes.
- Climate plays an important role in the global distribution of freshwater resources. Changing precipitation patterns and temperature conditions will alter the distribution and availability of freshwater resources, reducing reliable access to water for many people and their crops. Winter snowpack and mountain glaciers that provide water for human use are declining as a result of global warming.
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- By the end of grade 5:
- Research on a problem should be carried out-for example, through Internet searches, market research, or field observations-before beginning to design a solution. An often productive way to generate ideas is for people to work together to brainstorm, test, and refine possible solutions. (Core Idea: Engineering, Technology, and Applications of Science, ETS 1.B)
- By the end of grade 8:
- The ocean exerts a major influence on weather and climate by absorbing energy from the sun, releasing it over time and globally redistributing it through ocean currents. Greenhouse gases in the atmosphere absorb and retain the energy radiated from land and ocean surfaces, thereby regulating Earth’s average surface temperature and keeping it habitable. (Core Idea: Earth and Space Science 2.D)
- Human activities, such as the release of greenhouse gases from burning fossil fuels, are major factors in the current rise in Earth’s mean surface temperature (global warming). (Core Idea: Earth and Space Science 3.D)
- A solution needs to be tested, and then modified on the basis of the test results, in order to improve it. Models of all kinds are important for testing solutions, and computers are a valuable tool for simulating systems. Simulations are useful for predicting what would happen if various parameters of the model were changed, as well as for making improvements to the model based on peer and leader (e.g., teacher) feedback. (Core Idea: Engineering, Technology, and Applications of Science, ETS 1.B)
- By the end of grade 12:
- Climate change can occur when certain parts of the Earth’s system are altered. Geological evidence indicates that past climate changes were either sudden changes caused by alterations in the atmosphere; longer changes (e.g., ice ages) due to variations in solar output, or Earth’s orbit. The time scales of these changes varied from a few to millions of years. Changes in the atmosphere due to human activity have increased carbon dioxide concentrations and thus affect climate. (Core Idea: Earth and Space Science 2.D)
- Though the magnitudes of humans’ impacts are greater than they have ever been, so too are humans’ abilities to model, predict, and manage current and future impacts. Thus science and engineering will be essential both to understanding the possible impacts of global climate change and to informing decisions about how to slow its rate and consequences - for humanity as well as for the rest of the planet. (Core Idea: Earth and Space Science 3.D)
- Anthropogenic changes (induced by human activity) in the environment - including habitat destruction, pollution, introduction of invasive species, overexploitation, and climate change - can disrupt an ecosystem and threaten the survival of some species. (Core Idea: Life Science 2.C)
- Humanity faces major global challenges today, such as the need for supplies of clean water and food or for energy sources that minimize pollution, which can be addressed through engineering. (Core Idea: Engineering, Technology, and Applications of Science, ETS 1.A)
- Both physical models and computers can be used in various ways to aid in the engineering design process. (Core Idea: Engineering, Technology, and Applications of Science, ETS 1.B)
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- Make sense of problems and persevere in solving them.
- Reason abstractly and quantitatively.
- Model with mathematics.
- Use appropriate tools strategically.
- Attend to precision.
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