Jump to main content

What To Do About CO₂?


Grade Range
Group Size
2-4 students
Active Time
70-90 minutes
Total Time
70-90 minutes
Area of Science
Green Chemistry
Environmental Science
Ocean Sciences
Key Concepts
Carbon dioxide, carbon capture, carbon cycle, green chemistry, climate change, acids and bases, ocean acidification, greenhouse gases, renewable resources
A bowl of dry ice with carbon dioxide gas spilling over the sides and all over the table.


Where does CO₂ come from and how does excess carbon dioxide in the atmosphere affect the ocean and aquatic life? In this lesson students are introduced to the carbon cycle and explore pH and acidification with hands-on experiments. They then connect their experimental data with real-world data to evaluate claims about carbon dioxide and ocean acidification. Finally, students are introduced to how different companies and research groups are using green chemistry to build carbon capture technologies and use that carbon as a material for new eco-friendly products.

Learning Objectives

NGSS Alignment

This lesson helps students prepare for these Next Generation Science Standards Performance Expectations:


Decide if you will be doing both experiments outlined in the Explore section, or just one of them.

For Experiment #1 each student group will need:

For Experiment #2 each student group will need:

Also needed:

Background Information for Teachers

This section contains a quick review for teachers of the science and concepts covered in this lesson.
Our partner Beyond Benign also offers additional training in the theory and practice of green chemistry in the classroom. Explore Beyond Benign's professional development opportunities.

The pH scale ranges from 1 (acidic) to 14 (basic) with 7 designated as neutral. Ocean water is typically slightly basic.

Atmospheric carbon dioxide from both natural sources and human impact (e.g., the burning of fossil fuels) can be absorbed by ocean water where it dissolves and becomes carbonic acid. In the last century, the increased output of carbon dioxide from human activities has led to a measurable increase in atmospheric carbon. In turn, this has led to a measurable increase in dissolved CO2 in the ocean, and more acidic ocean waters. This phenomenon is known as ocean acidification. Ocean acidification reduces the availability of calcium carbonate minerals which are heavily used in the building and repair of many skeletons and exoskeletons in marine organisms including coral and shellfish.

The principles of green chemistry are being applied to prevent ocean acidification by capturing excess carbon dioxide before it is released into the atmosphere. This technology is cutting edge and evolving quickly. Watch the video to learn more about green chemistry.

Prep Work (20 minutes)

Engage (20 minutes)

Explore (30-50 minutes)

Reflect (20 minutes)


Make Career Connections

Free science fair projects.