Over the last fortnight the Year 4, 5 and 6 students have had incursions run by Belinda Bloxsome from CSIRO Sustainable Futures. Our whole school Mappen focus this term has been a study on Sustainability. The Year 4 and 5 classes have been learning more about the fragile biodiversity of St Emilie’s Bushland and the Year 6 students having been studying the CSIRO Carbon Concerns unit. These resources are available to schools through the Sustainable Futures program. Sustainable Futures is an education program that combines the latest in climate science with education in sustainability.
Over the two week period Belinda presented a variety of interesting activities to designed to challenge the students ideas about such topics as global warming, greenhouse gases, climate change, fossil fuels and the carbon cycle.
Week one for the gold classes focused on the Biodiversity Hotspot of South West WA. The students visited our school bushland to investigate in detail native flora. We then returned to class and Belinda showed the students how to upload the details on to the Living ATLAS of Australia. This is a citizen science initiative and anyone can do it. Here is an image of the students at work in the bushland.
Week two for the Blue classes was about carbon dioxide in the atmosphere and how the increase in carbon dioxide is affecting our climate and contributing to ocean acidification. The students conducted a most interesting investigation. They worked in their collaborative teams of three. Our investigation question – is there more carbon dioxide in our breath or in the air around us?
The students used red cabbage juice as a pH indicator. They squirted the liquid into each beaker using pippettes.
The students blew up two balloons. One balloon they filled with air from their lungs. The other balloon was filled with air from the atmosphere using a pump to collect it.
Once the students had trapped the air, they slowly ‘bubbled it’ into the beaker.
The students had to observe if there was change of colour in the liquid in each beaker and compare the colour to the pH indicator strip.
The students recorded their findings on a table for ‘before’ and ‘after’. As a class we worked out the average.
We concluded that the beaker with the gas from the air we breathed out became slightly more acidic (with a lower number). The carbon dioxide from our breath reacts with the water in the cabbage solution to form carbonic acid which changes the pH of the cabbage solution.
We compared these findings to ocean environments and concluded that the average pH of seawater at the ocean’s surface is 8.1, slightly alkaline but more acidic than the average pH before the industrial era began. When carbon dioxide from the atmosphere reacts with water it forms carbonic acid. The result is a lowering of the pH and a decrease in carbonate ion concentration in the water. Less carbonate ions in the water makes it difficult for marine organisms such as coral to build calcium carbonate shells and skeletons.