Lesson overview

This lesson examines the impacts of changes associated with climate change on the ocean, in particular, the impacts on particularly fragile ‘sentinel’ ocean environments, the Polar regions (Arctic and Antarctic) and tropical Coral Reefs. This lesson will explore some of the major impacts on these two ‘sentinel’ systems, and consider some of the implications for humans.

Learning outcomes

• Understand the range of potential impacts of increased CO₂ in the atmosphere
• Locate on a map areas of the ocean affected by climate change
• Describe how habitats such as the Arctic and coral reefs are being negatively impacted by human activity.
• Consider appropriate human responses

Lesson steps

1. Consequences of increased atmospheric CO₂ on the ocean (15 minutes)

Introduce the learning objectives using slide 2. Then share an overview of the impact of warming on the ocean using slides 4 to 11. Students should then use the information on the Student Sheet Climate change and the ocean to complete a mind map. This could be done individually, in pairs, or in small groups. A simpler set of recall questions is available as well on slide 13, with answers on slides 14 to 15.

2. Sentinel environments (5 minutes)

Explain that certain environments are particularly sensitive to environmental changes, making them both at severe risk; but also very suitable indicators of changes (much like the ‘canary in the coalmine’). Two particular environments are particularly appropriate ‘sentinels’ of the effects of atmospheric carbon dioxide. A series of slides is used to structure teacher exposition on these sentinel systems.

Slide 17 shows the sea surface temperature, which as expected is warmed in the tropics and cooler at the poles. However, the big issue is the sea surface temperature anomaly, the difference in current temperatures from the average. This is shown on slide 18. Particular note should be drawn to the ocean around Svalbard in the Arctic, showing an above 3ºC warming.

Slides 19 and 20 elaborate on the problems of a warming Arctic, and the fact that this is the fastest warming region on the planet.

Slides 21 to 24 focus on coral bleaching (if you are not familiar with this process, see the Teacher Update Will coral reefs survive this century? linked from this lesson’s resources.

Coral bleaching is a very visual change to an essential ocean ecosystem. Coral supports 25% of all marine species, as well as millions of lives and livelihoods. However, by 2100, there could be no or very little coral reef left as we know it.

3. The Arctic (15 minutes)

Sea ice is the dominant feature of the Arctic Ocean. It provides a habitat for animals and algae. Its presence is a key factor in the system of ocean circulation, and its bright surface helps to reflect solar heat back into the atmosphere. Use the embedded video on slide 26 to show how sea ice changes in both the Arctic and the Antarctic through the seasons. Then hand out the Student Sheet Arctic sea ice data analysis to students and go through the graphs using the slides. Students should then answer the questions on the accompanying student sheet.

Review the answers as well as the implications of Arctic sea ice loss using the answer sheet.

4. Tropical coral reefs (20 minutes)

Students may have an idea of what the coral reef looks like. In this section, students will watch two short videos showing the reef around the Maldives. The first video embedded on slide 32 shows a healthy reef. Students will probably note the diversity of different fish life, the variety of colours and movement. If students were in the water, they would probably hear the snap, crackle, and pop of life on the reef.

The second video embedded on slide 33 shows coral rubble after bleaching. Bleaching occurs when warmer ocean temperatures can lead to coral dying. After coral has died, the structures are battered by the waves and turn into rubble. With the loss of coral there is less life overall. Review the videos using the questions on slide 34. Coral scientists feel emotions too, and mention their feelings of sadness and anger when they see damaged coral reefs, and how they can use these to power their work to protect the reef.

Dependent on lesson timing, use the creative activity on Student Sheet Coral reef: Maldives case study to develop students’ communication skills.

5. Reflection on conservation (5 minutes)

The lesson ends by asking students to reflect on the changes to the Polar/Arctic and/or coral reefs environments, and consider implications for international collaboration to solve these issues given the complexities of ocean governance.

Geography KS3

• Locate the world's countries, using maps to focus on major ocean regions, concentrating on their environmental regions
• Understand how human and physical processes interact to influence and change landscapes, environments, and the climate;
• Physical geography relating to weather and climate, including the change in climate from the Ice Age to the present; and glaciation and hydrology.
• Build on their knowledge of globes, maps, and atlases, and apply and develop this knowledge routinely in the classroom and in the field.

Cross-curricular connections

• Science: Relationships in an ecosystem, environmental changes, and effects on living things; Earth and atmospheric science, including climate change and its effects on the environment