Blue Chemistry

Education Modules > Module 3 > High School > Blue Chemistry > Impacts

Impacts—Ocean Acidification

Summary: The ocean is becoming more acidic because of carbon dioxide emissions. The change threatens the health marine organisms that depend on available calcium carbonate to make their shells. In this topic guide, students use models and real data to explore the relationship between atmospheric CO2 and ocean pH, and the impacts that pH changes have on marine organisms.

Concepts to teach:


  1. Increased levels of atmospheric CO2 leads to a decrease in ocean pH
  2. Ocean acidification leads to decreased amounts of available calcium carbonate that many marine organisms need to make their shells
  3. Scientists use data to create models that forecast future conditions

Standards: NGSS Performance Expectations

  • HS-ESS3-6. Use a computational representation to illustrate the relationships among Earth systems and how those relationships are being modified due to human activity

Specific Objectives:
Students will be able to:

  1. Use data to describe the process and driving factor behind ocean acidification
  2. Use online tools to recreate climate change model scenarios and examine effects of increased CO2 on ocean acidity and carbonate saturation levels
  3. Identify expected future impacts of ocean acidification on marine organisms and ecosystems

Activity Links and Resources:

  • Understanding Ocean Acidification from Data in the Classroom—Use NOAA data to learn about ocean acidification.
    • Teacher's Guide and resources
    • Level 1 Explore NOAA data to understand patterns and relationships that explain variation in ocean pH
    • Levels 2-4 helps students use NOAA data to explore the impacts of ocean acidification
  • The NOAA Coral Reef Conservation Program has collected excellent OA educational resources for high school learners, including:
    • The Understanding Ocean Acidification Data in the Classroom unit, above
    • The Power of pH: Changing Ocean Chemistry from Monterey Bay Aquarium - Review what pH is and how CO2 released from the burning of fossil fuels increases the acidity of the ocean
    • Ocean Acidification Lab from WHOI and OA Subcommittee, Ocean Carbon and Biogeochemistry Program—These classroom activities are designed to help students understand the science behind ocean acidification.
      dioxide released from the burning of fossil fuels increases the acidity of the ocean.
    • Virtual Urchin: Our Acidifying Ocean—With this interactive online laboratory experiment, students discover the effects of acidified sea water on sea urchin larval growth
  • Multimedia Resources about Ocean Acidification


  • The Data in the Classroom resource includes assessment components, including
    • Check for Understanding interactive questions at the end of Levels 1, 2, and 4
    • The Teacher Guide contains detailed questioning strategies, student worksheets and answer keys
    • Level 5 in the Data in the Classroom unit challenges students to come up with their own hypothesis about ocean acidification and then look for NOAA data that will support or reject that hypothesis.