Lesson C2 - Thermal expansion of the ocean and sea level rise

MAIN SUBJECTS

Natural sciences

DURATION

Preparation: 15min

Activity: 1h–1h30

SUMMARY

The students carry out an experiment to ascertain how the thermal expansion of seawater contributes to sea level rise. A documentary analysis allows them to discuss the different impacts of sea level rise (on ecosystems and human communities).

KEY IDEAS

As the temperature of the atmosphere rises, so does the temperature of the ocean.
The global mean sea level has already risen around 15 cm since 1900. According to different scenarios, it will rise further – by between 25 cm and over 1 m by 2100.
Water, like all liquids, expands in volume when heated. This is called thermal expansion, and is one cause of sea level rise.
Due to sea level rise, coastal regions will increasingly be flooded, leading to coastal erosion.
In 2010, about 30 % of the global population lived less than 100 km from the ocean.
Coastal ecosystems are at risk of being altered or destroyed.
Saltwater may seep into groundwater.