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Ocean acidification and CO2 absorption
In this practical experiment, students model the process of ocean acidification by generating carbon dioxide in an enclosed water–air system. As CO₂ dissolves in the water, it forms carbonic acid, lowering the pH and changing the colour of an indicator, demonstrating how rising atmospheric CO₂ affects marine chemistry. A follow-up investigation compares CO₂ solubility in warm and cold water, helping students understand how global warming reduces the ocean’s ability to absorb carbon dioxide and buffer climate change.
©The Royal Meteorological Society. All rights reserved.
Preparation
What you need
- The ocean acidification and absorption activity guide
Equipment
- Bicarbonate of soda (baking soda)
- White vinegar
- Bromothymol blue Indicator (diluted with water: 8 ml bromothymol blue (0.04% aqueous) to 1 litre of water)
- 2 x 500 ml Beakers
- Small plastic or paper cup (100 ml)
- Masking tape
- 2 x Petri dishes or lid for large beakers
- Teaspoon or 5 ml measuring cylinder
- Two sheets of white paper
- Safety glasses and lab coat
Location
Indoors
Resources
Step by step
- Download the ocean acidification and absorption activity guide.
- Read the guidance for step by step instructions for each activity.
Curriculum links
This activity can be used to support curriculum knowledge and skill development in Chemistry, Geography and Physics, alongside enhancing nature education, with age appropriate adaptations.
Thumbnail image: ©The Royal Meteorological Society. All rights reserved.