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Off Base - Acidity of oceans

NOAA Ocean Explorer

This lesson guides a student inquiry into properties of the ocean's carbonate buffer system, and how changes in atmospheric carbon dioxide levels may affect ocean pH and biological organisms that depend on calcification.

Activity takes two 45-minute class periods. Basic chemistry laboratory equipment required.

Learn more about Teaching Climate Literacy and Energy Awareness»

ngssSee how this Activity supports the Next Generation Science Standards»
High School: 1 Performance Expectation, 4 Disciplinary Core Ideas, 6 Cross Cutting Concepts, 7 Science and Engineering Practices

Climate Literacy
About Teaching Climate Literacy

Climate's role in habitats ranges and adaptation of species to climate changes
About Teaching Principle 3
Other materials addressing 3a
Increased acidity of oceans and negative impacts on food chain due to increasing carbon dioxide levels
About Teaching Principle 7
Other materials addressing 7d

Excellence in Environmental Education Guidelines

2. Knowledge of Environmental Processes and Systems:2.1 The Earth as a Physical System:B) Changes in matter
Other materials addressing:
B) Changes in matter.
2. Knowledge of Environmental Processes and Systems:2.2 The Living Environment:A) Organisms, populations, and communities
Other materials addressing:
A) Organisms, populations, and communities.
2. Knowledge of Environmental Processes and Systems:2.2 The Living Environment:C) Systems and connections
Other materials addressing:
C) Systems and connections.
2. Knowledge of Environmental Processes and Systems:2.4 Environment and Society:A) Human/environment interactions
Other materials addressing:
A) Human/environment interactions.
2. Knowledge of Environmental Processes and Systems:2.4 Environment and Society:E) Environmental Issues
Other materials addressing:
E) Environmental Issues.

Notes From Our Reviewers The CLEAN collection is hand-picked and rigorously reviewed for scientific accuracy and classroom effectiveness. Read what our review team had to say about this resource below or learn more about how CLEAN reviews teaching materials
Teaching Tips | Science | Pedagogy | Technical Details

About the Science

  • An example of how both laboratory and field work support the understanding of global changes.
  • Activity has a strong chemistry component.
  • Great way of researching the buffer mechanism of the ocean by performing experiments.
  • Comment from scientist: Activity is based on the very newest scientific research.
  • A lot of good supplemental materials listed. This is a clever activity for students to understand buffering. The hands-on part of the activity should help the students understand how seawater can absorb some CO2 (as carbonic acid) before the pH changes. I like that this important concept is incorporated into a larger discussion about ocean acidification due to CO2 emissions, and how acidification will affect coral reefs and other organisms.

About the Pedagogy

  • Activity shows the dangers anthropogenic activity has on the ocean. It also reflects on our standard of living and the implications it has for the environment. This makes the students think and might even result in questioning the necessity of some of the luxuries we have.
  • Complete activity with pedagogic guidance embedded within the activity.
  • Nice blend of hands-on and Web research/worksheet activities.
  • Includes worksheets that could be used for assessment.

Next Generation Science Standards See how this Activity supports:

High School

Performance Expectations: 1

HS-PS1-6: Refine the design of a chemical system by specifying a change in conditions that would produce increased amounts of products at equilibrium

Disciplinary Core Ideas: 4

HS-PS1.B2:In many situations, a dynamic and condition-dependent balance between a reaction and the reverse reaction determines the numbers of all types of molecules present.

HS-ESS2.D1: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.

HS-ESS2.D4: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.

HS-LS2.C2:Moreover, 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.

Cross Cutting Concepts: 6

Patterns, Cause and effect, Scale, Proportion and Quantity, Systems and System Models, Energy and Matter, Stability and Change

HS-C1.5:Empirical evidence is needed to identify patterns.

HS-C2.1:Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.

HS-C3.1:The significance of a phenomenon is dependent on the scale, proportion, and quantity at which it occurs.

HS-C4.2: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.

HS-C5.4: Energy drives the cycling of matter within and between systems.

HS-C7.1:Much of science deals with constructing explanations of how things change and how they remain stable.

Science and Engineering Practices: 7

Asking Questions and Defining Problems, Planning and Carrying Out Investigations, Analyzing and Interpreting Data, Using Mathematics and Computational Thinking, Constructing Explanations and Designing Solutions, Obtaining, Evaluating, and Communicating Information

HS-P1.4:ask questions to clarify and refine a model, an explanation, or an engineering problem

HS-P3.1:Plan an investigation or test a design individually and collaboratively to produce data to serve as the basis for evidence as part of building and revising models, supporting explanations for phenomena, or testing solutions to problems. Consider possible confounding variables or effects and evaluate the investigation’s design to ensure variables are controlled.

HS-P4.1:Analyze data using tools, technologies, and/or models (e.g., computational, mathematical) in order to make valid and reliable scientific claims or determine an optimal design solution.

HS-P5.2:Use mathematical, computational, and/or algorithmic representations of phenomena or design solutions to describe and/or support claims and/or explanations.

HS-P6.2: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.

HS-P6.4:Apply scientific reasoning, theory, and/or models to link evidence to the claims to assess the extent to which the reasoning and data support the explanation or conclusion.

HS-P8.5:Communicate scientific and/or technical information or ideas (e.g. about phenomena and/or the process of development and the design and performance of a proposed process or system) in multiple formats (i.e., orally, graphically, textually, mathematically).

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