Summary Look at the ways that humans are having a big enough environmental impact that we are changing the chemistry and ecosystems of the world Science content Earth/Space: Sustainable practices, Interconnectedness (2, 5, 7) Activities in this lesson CO2 acidifies water Ocean sediment cores Oil spill clean up simulation Procedure The amount of CO2 in the air determines how acidic our oceans are. We’ll see how this works. Do the CO2 acidifies water activity. In the same way, CO2 in air increases from emissions, the acidity of the ocean increases. More info: The air does not have as much CO2 as your breath. The oceans are currently absorbing about a quarter of the CO2 released into the atmosphere. Ocean has changed by 0.1pH unit, which is a 30% increase, since the industrial era. Lakes are more variable because of the rock type they are in, but they are also becoming more acidic. A tiny change in acidity has a profound effect on ocean life (making shells), and so food chains. Continue with activity: Luckily this acidification is reversible. So if we can reduce the CO2 in the air the ocean water pH will rise again. Try it: waft and shake in air, which has less CO2 than your breath, keep cycling, to see what happens. With emissions reduction, the CO2 in air goes down and oceans will recover. Look at ocean sediment cores show us a historical global warming event, and the effect on the oceans. At our current rate of emissions, we are releasing CO2 into the air faster than this event. The image also shows how the oceans recovered - if we choose as a society to vastly reduce our emissions, the oceans can recover. Another impact on oceans is oil spills. We can choose to vastly reduce oil extraction and transportation. As long as we are moving oil around the world, there are likely to be spills that harm ocean life. We will model how spills are cleaned up to see how effective they are.oil spill cleanup activity. Cleaning up an oil spill is a huge task. If it happens it needs to be done properly. We should be reducing the amount of oil we burn anyway, so with less in use, the spills will also drop. Grades taught Gr 7
