Question

Scenario: For each of the issues below, please decide which choice is the right one and explain why that is the case. Hint: Your justification can have economic impact but should not be on a purely economic basis.

1. We have just built a new wind farm to replace a coal-based utility power source. The wind turbines require a small amount of grease lubricant (about 20 lbs) that allows the blades to turn freely. The grease is supplied in a sealed bearing that is changed at every lube change. We have a choice between (a) - a bio-based bio-degradable lubricant that will last 3 months and (b) - a petroleum-based synthetic lubricant that will last a year to coincide with the maintenance schedule of the wind farm. Which would you use? Why?
2. A small dam on the river would provide some Inuit villagers with clean hydropower in their village. But the dam would be in the way of fish migrating up the river to spawn. A) Build the dam but put in money for buying fish for the Inuit in perpetuity. B) Don’t build the dam. C) Build the dam with a raceway for the fish. D) Supply the Inuit with power from the next village. Which one is right?
3. I plan to grow algae that use CO2 as a nutrient using wastewater from the municipal sewage. I will then burn the algae to generate power and CO2 but will send the CO2 back to the anaerobic fermenter. Voila, power with zero carbon footprint forever. Is this reasonable? Y or N
4. My sister makes her own yoghurt every night and saves a little bit of the yogurt the next day to use as starter for the next batch. She claims that is what sustainability is all about. Is she correct? Y or N.
5. My niece claims that eating any milk products at all (and red meat) is bad for the planet. She has turned vegan. Does that support a greener planet and sustainability? Y or N

Answer 1

1. Given the options, the appropriate choice would be to use the petroleum-based synthetic lubricant (b). The primary reason for this is the alignment of the product's lifespan with the maintenance schedule of the wind farm. This selection will minimize the frequency of maintenance visits, which, in turn, reduces the amount of energy and resources used for transportation and servicing. Furthermore, it is essential to consider the entire life cycle of the products, from production to disposal. The bio-based lubricant, despite being biodegradable, needs to be replaced four times more frequently, potentially leading to higher total environmental impact due to increased production, transportation, and waste generation.

2. The appropriate choice in this situation would be to build the dam with a fish raceway (C). The reason for this decision is that it allows for the simultaneous achievement of two important goals: generating clean energy and preserving local ecosystems. Constructing a fish raceway or fish ladder allows the fish to continue their migration patterns, which is crucial for maintaining biodiversity and the health of the ecosystem. While options A and D also provide clean energy, they either disrupt the ecosystem or rely on external power sources, which might not be as reliable or sustainable in the long term.

3. This scenario is reasonable in principle (Y), but there are a few caveats. This process could indeed lead to a reduction in net CO2 emissions, given that the CO2 produced when burning the algae is reabsorbed by the next generation of algae. This closed-loop system can theoretically achieve carbon neutrality. However, it's essential to consider that energy is also required for the cultivation, harvesting, and processing of the algae, as well as the operation of the power generation and CO2 capture equipment. Thus, the overall sustainability of the process depends on how that energy is generated.

4. Your sister is correct (Y), in a broad sense. Sustainability is about using resources in a way that meets current needs without compromising the ability of future generations to meet their own needs. By using a portion of today's yogurt to start the next batch, she is practicing a form of sustainability. She is reducing waste and the need for new resources (starter cultures). However, it's worth noting that this is just one small aspect of sustainability, which is a complex concept encompassing many aspects of human activity and environmental impact.

5. Your niece is correct to some extent (Y), as a vegan diet tends to have a lower environmental impact compared to a diet high in animal products. Livestock farming contributes significantly to greenhouse gas emissions, land use, and water use. It's also associated with deforestation and biodiversity loss. Therefore, transitioning to a plant-based diet can be considered a more sustainable choice in terms of resource use and environmental impact. However, it's essential to note that not all plant-based foods are equally sustainable, and factors like local availability, farming practices, and transportation distances also influence the overall environmental footprint of a person's diet.