Human Impacts

Apply scientific principles to design a method for monitoring and minimizing a human impact on the environment.

Construct an argument supported by evidence for how increases in human population and per-capita consumption of natural resources impact Earth's systems.

Ask questions to clarify evidence of the factors that have caused the rise in global temperatures over the past century.

Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.

Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.

• Weather and climate are influenced by interactions involving sunlight, the ocean, the atmosphere, ice, landforms, and living things. These interactions vary with latitude, altitude, and local and regional geography, all of which can affect oceanic and atmospheric flow patterns.
• Because these patterns are so complex, weather can only be predicted probabilistically.
• 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.

• Human activities have significantly altered the biosphere, sometimes damaging or destroying natural habitats and causing the extinction of other species. But changes to Earth’s environments can have different impacts (negative and positive) for different living things.
• Typically as human populations and per-capita consumption of natural resources increase, so do the negative impacts on Earth unless the activities and technologies involved are engineered otherwise.

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). Reducing the level of climate change and reducing human vulnerability to whatever climate changes do occur depend on the understanding of climate science, engineering capabilities, and other kinds of knowledge, such as understanding of human behavior and on applying that knowledge wisely in decisions and activities.

• Sometimes parts of different solutions can be combined to create a solution that is better than any of its predecessors.
• Models of all kinds are important for testing solutions.
• A solution needs to be tested, and then modified on the basis of the test results in order to improve it. There are systematic processes for evaluating solutions with respect to how well they meet criteria and constraints of a problem.

• Although one design may not perform the best across all tests, identifying the characteristics of the design that performed the best in each test can provide useful information for the redesign process—that is, some of those characteristics may be incorporated into the new design.
• The iterative process of testing the most promising solutions and modifying what is proposed on the basis of the test results leads to greater refinement and ultimately to an optimal solution.

• Develop and use a model to describe phenomena.
• Develop a model to describe unobservable mechanisms.
• Develop a model to generate data to test ideas about designed systems, including those representing inputs and outputs.
• Develop a model to predict and/or describe phenomena.

• Collect data to produce data to serve as the basis for evidence to answer scientific questions or test design solutions under a range of conditions.
• Plan an investigation individually and collaboratively, and in the design: identify independent and dependent variables and controls, what tools are needed to do the gathering, how measurements will be recorded, and how many data are needed to support a claim.
• Conduct an investigation and evaluate the experimental design to produce data to serve as the basis for evidence that can meet the goals of the investigation.

• Construct a scientific explanation based on valid and reliable evidence obtained from sources (including the students’ own experiments) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.
• Construct a scientific explanation based on valid and reliable evidence obtained from sources (including the students’ own experiments) and the assumption that theories and laws that describe nature operate today as they did in the past and will continue to do so in the future.
• Construct an explanation that includes qualitative or quantitative relationships between variables that predict phenomena.
• Apply scientific ideas to construct an explanation for real-world phenomena, examples, or events.
• Construct an explanation that includes qualitative or quantitative relationships between variables that describe phenomena.
• Undertake a design project, engaging in the design cycle, to construct and/or implement a solution that meets specific design criteria and constraints.
• Apply scientific ideas or principles to design, construct, and test a design of an object, tool, process or system.

• Cause and effect relationships may be used to predict phenomena in natural or designed systems.
• Relationships can be classified as causal or correlational, and correlation does not necessarily imply causation.
• Phenomena may have more than one cause, and some cause and effect relationships in systems can only be described using probability.

• Time, space, and energy phenomena can be observed at various scales using models to study systems that are too large or too small.
• Phenomena that can be observed at one scale may not be observable at another scale.
• Proportional relationships (e.g. speed as the ratio of distance traveled to time taken) among different types of quantities provide information about the magnitude of properties and processes.

• Models can be used to represent systems and their interactions—such as inputs, processes and outputs—and energy, matter, and information flows within systems.
• Systems may interact with other systems; they may have sub-systems and be a part of larger complex systems.

• Explanations of stability and change in natural or designed systems can be constructed by examining the changes over time and processes at different scales, including the atomic scale.
• Stability might be disturbed either by sudden events or gradual changes that accumulate over time.
• Small changes in one part of a system might cause large changes in another part.
• Explanations of stability and change in natural or designed systems can be constructed by examining the changes over time and forces at different scales.

Use a model to describe how variations in the flow of energy into and out of Earth’s systems result in changes in climate.

Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.

Use a computational representation to illustrate the relationships among Earth systems and how those relationships are being modified due to human activity.

Use a computer simulation to model the impact of proposed solutions to a complex real-world problem with numerous criteria and constraints on interactions within and between systems relevant to the problem.

• The foundation for Earth’s global climate systems is the electromagnetic radiation from the sun, as well as its reflection, absorption, storage, and redistribution among the atmosphere, ocean, and land systems, and this energy’s re-radiation into space.
• Gradual atmospheric changes were due to plants and other organisms that captured carbon dioxide and released oxygen.
• Changes in the atmosphere due to human activity have increased carbon dioxide concentrations and thus affect climate.
• Current models predict that, although future regional climate changes will be complex and varied, average global temperatures will continue to rise. The outcomes predicted by global climate models strongly depend on the amounts of human-generated greenhouse gases added to the atmosphere each year and by the ways in which these gases are absorbed by the ocean and biosphere.

• The sustainability of human societies and the biodiversity that supports them requires responsible management of natural resources.
• Scientists and engineers can make major contributions by developing technologies that produce less pollution and waste and that preclude ecosystem degradation.

• Though the magnitudes of human impacts are greater than they have ever been, so too are human abilities to model, predict, and manage current and future impacts.
• Through computer simulations and other studies, important discoveries are still being made about how the ocean, the atmosphere, and the biosphere interact and are modified in response to human activities.

• When evaluating solutions, it is important to take into account a range of constraints, including cost, safety, reliability, and aesthetics, and to consider social, cultural, and environmental impacts.
• Both physical models and computers can be used in various ways to aid in the engineering design process. Computers are useful for a variety of purposes, such as running simulations to test different ways of solving a problem or to see which one is most efficient or economical; and in making a persuasive presentation to a client about how a given design will meet his or her needs.

Criteria may need to be broken down into simpler ones that can be approached systematically, and decisions about the priority of certain criteria over others (trade-offs) may be needed.

• Use a model to provide mechanistic accounts of phenomena.
• Develop and use a model based on evidence to illustrate the relationships between systems or between components of a system.
• Use a model to predict the relationships between systems or between components of a system.

• Plan and conduct an investigation individually and collaboratively to produce data to serve as the basis for evidence, and in the design: decide on types, how much, and accuracy of data needed to produce reliable measurements and consider limitations on the precision of the data (e.g., number of trials, cost, risk, time), and refine the design accordingly.
• Science investigations use diverse methods and do not always use the same set of procedures to obtain data.
• New technologies advance scientific knowledge.
• Scientific inquiry is characterized by a common set of values that include: logical thinking, precision, open-mindedness, objectivity, skepticism, replicability of results, and honest and ethical reporting of findings.

• Apply scientific reasoning to link evidence to the claims to assess the extent to which the reasoning and data support the explanation or conclusion.
• Construct and revise an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.
• Apply scientific principles and evidence to provide an explanation of phenomena and solve design problems, taking into account possible unanticipated effects.
• Apply scientific ideas to solve a design problem, taking into account possible unanticipated effects.
• Design, evaluate, and/or refine a solution to a complex real-world problem, based on scientific knowledge, student-generated sources of evidence, prioritized criteria, and tradeoff considerations.

• Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.
• Systems can be designed to cause a desired effect.
• Cause and effect relationships can be suggested and predicted for complex natural and human designed systems by examining what is known about smaller scale mechanisms within the system.

• The significance of a phenomenon is dependent on the scale, proportion, and quantity at which it occurs.
• Algebraic thinking is used to examine scientific data and predict the effect of a change in one variable on another (e.g., linear growth vs. exponential growth).
• Using the concept of orders of magnitude allows one to understand how a model at one scale relates to a model at another scale.

• When investigating or describing a system, the boundaries and initial conditions of the system need to be defined and their inputs and outputs analyzed and described using models.
• Models (e.g., physical, mathematical, computer models) can be used to simulate systems and interactions—including energy, matter, and information flows— within and between systems at different scales.
• Models can be used to predict the behavior of a system, but these predictions have limited precision and reliability due to the assumptions and approximations inherent in models.

• Much of science deals with constructing explanations of how things change and how they remain stable.
• Change and rates of change can be quantified and modeled over very short or very long periods of time. Some system changes are irreversible.
• Feedback (negative or positive) can stabilize or destabilize a system.
• Systems can be designed for greater or lesser stability.