Summary Find out how fossils are discovered, and how we read them to show past climate change events. Show how oceans are acidified by increased carbon dioxide in the atmosphere. Science content Earth/Space: Weather, Seasons, Climate Change (K, 1, 4, 7) Earth/Space: Fossil records, Geologic time scale (7) Activities in this lesson Sedimentary uplifting (with optional fossil discovery) Ocean sediment cores CO2 acidifies water Materials Materials in the activities Procedure Do the sedimentary uplifting with fossil discovery activity to show how fossils are made and how they are revealed. Sedimentary rocks shows us what animals were alive on Earth at what time. The chemistry of the rock layers also show us how the Earth’s atmosphere and climate changed through time. As well as studying sedimentary rocks on land, the sediment layers at the bottom of the ocean reveal Earth’s history back 65 million years (the animals alive through that time as well as the climate). Show students ocean sediment core samples from the Paleocene-Eocene Thermal Maximum (PETM), show how the change of CO2 in the atmosphere changed the ocean, acidifying it so that shells were dissolved before they were deposited on the ocean bed. The CO2 in the air determines how acid our oceans are. Do the CO2 acidifies water activity to show how this works. Stress to students that the acidification of the oceans is reversible. As we lower the CO2 in the atmosphere through emission reduction, the oceans will recover. Grades taught Gr 6 Gr 7
