Greener Greens?

Imaginar

• Students watch a short documentary on Quinoa produced by Channel 4 news and are then prompted to find more information about the topics raised (this raises issues of bias and reliability of data as many of the claims made in the documentary cannot be substantiated)

Criar

Explanatory notes on the use of a Student Action Cycle approach

‘Greener Greens’ is a collection of student inquiry-based research projects that question ethical and sustainability issues surrounding global food production and consumption in addition to considering potential resulting impacts on climate change from transportation and concomittant reductions in biodiversity through changes to agricultural practices. It challenges students’ assumptions that the all-year-round availability of non-seasonal fruits and vegetables is necessary, or moral, through the critical analysis of data and personal case studies. The role of science in society on a global and personal scale is used to evaluate commercial and media-based arguments for accuracy and bias. Proceeding through the ‘Greener Greens’ action cycle, students addressed the following elements and learning outcomes from the contextual strands of the Specification for Junior Cycle Science, (SJCS):

The trigger scenario for the “Greener Greens” student action cycle (SAC) was the opening of a new school canteen, just before the Christmas break, that offered, as part of its menu, ‘seasonal fruits’. When the students from two First Year class groups, who had purchased this option, were asked what they had received they responded “pineapple and bananas”. When asked by the teacher whether these items were seasonal, he was met, by and large, with shrugs and blank looks. This led to posing the question ‘How could we find out?’

The question was discussed by students in both classes, in small groups and later in pleneries where a number of strategies were proposed. These included an internet search, asking their parents, and checking food labels to identify Irish produce, which if fresh, should be in season. A ‘throw away’ comment by the teacher implying that things had been very different in his youth prompted student to suggest that they could ask their parents, or oldest relatives, as to how the availablity of fruits and vegetables might have changed over their lifetimes.

Moving from the planning stage of the SAC in class to the exploration stage at home, students tasked themselves with collecting as much information as they could for class discussions to be held the following week.

The collaborative plenaries, discussing the changes that the students’ relatives had experienced through their lifetimes, delivered dramatic diversity in responses which the classes found both remarkable and stimulating. Not only did discussion focus on the change by urban dwellers from seasonal produce purchased from a greengrocer to packaged, all-year-round supermarket provisions, but rural grow-your-own options were also mentioned. The multi-cultural nature of the classes revealed itself in differences in diets for students who had arrived from other European countries, India, Africa and Asia. Cultural differences were discussed enthusiastically and freeflowing conversations ensued. Out of all of this came an appreciation that seasonality and commercial profit were potentially opposite sides of the same coin and that supermarkets stock produce from around the World to meet customer demand. Both class groups suggested that it might be important to find out where the food they ate originated from and decided the easiest way of establishing this was to collect food labels on packaging. The establishment of the success criteria stage of the SAC would develop later as a number of collaborate and explore loops were initiated and completed by students both during and after the collection of the food labels.

In January, on return to school, the classes had assembled a large collection of supermarket packaging. Through collaboration by the students, independently in both classes, it was decided that the name of each food item, its mass and country of origin should be recorded and displayed on a World atlas in the classroom. This process was comenced by one class with ‘post-it’ notes, but very quickly disatisfaction with this method was voiced by the group as multiple product ‘post-it’ notes for countries such as Spain and Holland obscured each other. In resolving this, members of the class opted to position the labels around the atlas and join them to the country of origin with coloured string. The second class, on observing the work that had been started by the first, raised the issue that, in their opinion, the presentation would be much improved if the labels also carried illustrations of the produce. One student suggested that the distance travelled should also be included and this was readily accepted by the group who used the capital city of the country of origin, Dublin and www.distancefromto.netto determine this data. During this phase of the SAC, students in both classes spotted labels for ‘Charlotte potatoes’, whose country of origin was France. This information was rapidly shared and the class were generally annoyed that an item synonymous with Irish agriculture should be imported for sale. The teacher again offered a ‘throw away’ comment to the effect that what difference would it make where the produce came from. Students in both classes responded that if the item had to be transported then this would produce carbon dioxide which, as a greenhouse gas, could contribute to climate change. From this response, the students decided on the last two items for inclusion on data cards; namely the mass and volume of carbon dioxide produced by transporting the item and whether or not the item could be grown in Ireland. With success criteria established for communicating findings, students then proceded to conduct the task by producing computer generated labels for display on the atlas; these included web images for the produce rather than their own drawings as a consequence of student initiated negotiations that were necessary because individuals in both classes failed to agree on which of their illustrations should appear on the finished article.

Students were given an Excel spreadsheet to calculate the volume and mass of carbon dioxide produced. 

The assumptions made to set the formula for the calculation were that the fuel used was diesel (C₁₂H₂₃) with a combustion formula of

4C₁₂H₂₃  +  71O₂  ….. 48CO₂  +  46H₂O                   (a)

Using values of 50.1 kJ/mol for C₁₂H₂₃, 0 kJ/mol for O₂, -393.5 kJ/mol for CO₂and -229 kJ/mol for H₂O to solve for DG.

46(-229)  + 48(-394) - 4(50.1) = -29622 kJ for equation (a)

Therefore dividing equation (a) by 4 for 1 mole of diesel, 7,405 kJ/mol diesel yields 12 moles of CO₂

Taking energy efficiency at 50%, for every 7,405 kJ of work done, twice as much, or 24 moles of CO₂would be released.

Taking:  work done = force x distance, 100g = 1N and 1 mole of CO₂gas occupies 22.4L with a mass of 44g.

590g of Braeburn apples travelling 1,255Km from Germany:

work done  = 5.9 x  1,255,000 = 7,404.5 kJ

therefore        24 moles CO₂released = 538L = 1.06Kg

An item of packaging brought in was from Peruvian quinoa. In their research, one group of students located a vlog, from Channel 4 News, (https://www. youtube.com/watch?v=Hdl8tzldsDY),  that indicated that a consequence of the Western desire for the superfood, quinoa, was chronic malnutrition amonst Peruvian subsistence farmers and their children; figures of 14% of children under the age of 5 were quoted. This discovery acted as a trigger for another iteration of the explore, collaborate stages of the SAC. Very rapidly alternative data was retreieved that indicated that the original news vlog was a biased representation and that other factors were at play in the Andes. A discussion evolved around the reliability of data and its freedom from bias which developed into students establishing the success criteria for establishing this such that the information be located in multiple reliable sources that each substantiated each other; the use of Wikipedia was discounted as students felt that this could not be reliable if contributers were able to edit content.

Students, armed with this set of validatory tools, then decided to look at some of the other issues that had been raised during the earlier stages of the SAC, in particular, loss of biodiversity and climate change arising from monoculture agricultural practices.

The next student generated ‘conduct task’ stage of this SAC largely focussed on palm oil production; that students discovered was leading to large scale removal of endemic tropical vegation to produce massive swathes of uniform vegetation. Several environmental impacts from large scale monoculture were investigated and students’ discussions centred on boycotting products containing palm oil; which in turn generated an ‘explore’ phase to identify these.

Finally, in wrapping together all aspects of the larger topic, students suggested a variety of formats for presenting their findings. The overall concensus was to produce educational board-games that could have positive and negative choice points, such as snakes and ladders and monopoly derivatives.

Two other activities that developed out of this SAC are worth note. Both originated out of the discussions about country living and growing one’s own produce. 

The first activity  was the incubation of chicken eggs in class, where students took responsibility for turning them regularly and monitoring them through the period of incubation. Those that hatched were kept in class for a fortnight and proved a large draw for interest around the school with the classroom full of students before and after school and during breaks.

The second activity involved students attempting to grow their own produce. This was only partially successful as the term dates precluded effective work on this through the summer months; though students did suggest and start to plan a visit to an interactive centre, that promotes ecological awareness and sustainable living, to assist with their crop production.

The ‘reflect’ stage of the SAC was completed as an after module personal assessment and supported the continued maintenance of learning logs by the students.

Partilhar

OTHER SUGGESTIONS:

• Students visit a local farm/ education centre and learn about crop production.
• Students attempt to grow their own fruits or vegetables ( once planted, these need to be regularly monitored)
• Students incubate hens eggs in the classroom, turning them regularly and then watch their development for a week post hatching.