Question 2 of 5: Green Engineering Principles and Newspaper LCA

Question 2: Green Engineering Principles and Newspaper LCA (25 marks)

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

(a) Targeted Durability

Design a product to last only its intended service life—e.g. single-use packaging from compostable materials instead of permanent plastic—so it degrades harmlessly rather than persisting as waste.

(b) Embedded Entropy and Complexity as an Investment

Highly ordered, complex materials (with low entropy) took large amounts of energy to create, so that investment should be preserved by reuse or remanufacture rather than destroyed by downcycling. Example: a microprocessor or precision electronic assembly embodies enormous processing energy and complexity; recovering and reusing the working component (or remanufacturing the device) preserves that embedded investment, whereas shredding it to recover trace base metals discards it. Preserving embedded complexity prevents the pollution and energy of making a complex part anew.

(c) Output-Pulled, Not Input-Pushed

Systems should be driven by actual demand ("pull") rather than by pushing material and energy through to forecast ("push"), which creates overproduction and waste. Example: a just-in-time / make-to-order production system produces goods only in response to real customer orders, so it does not manufacture excess inventory that may become obsolete and be scrapped—preventing the material and energy waste of overproduction. Printing newspapers to actual demand rather than large speculative runs is a direct instance.

(d) LCA: Newsprint versus Leased E-Readers

(i) Functional unit: delivering the daily news to one subscriber for a defined period (e.g. one year of daily editions)—so the recurring consumption of paper is compared fairly with the one-time device that is reused daily. (ii) Four stages: raw-material extraction; manufacturing/production; distribution/use; and end-of-life. (iii) Material/energy uses and higher-impact alternative by stage:

• Raw materials: newsprint consumes wood pulp, water, and ink every day; the e-reader consumes metals, rare earths, plastics, and a battery once. Per functional unit (a year of daily papers), newsprint is worse because material is consumed every single day.
• Manufacturing: paper-making and daily printing use energy repeatedly; e-reader fabrication (semiconductors, battery) is energy- and toxics-intensive but one-time. For a single day the e-reader is worse; over a year of daily editions, cumulative printing becomes the larger burden.
• Distribution/use: newspapers are physically trucked to subscribers daily (fuel, emissions); the e-reader downloads news electronically (server/network energy plus daily charging). Physical newsprint distribution is generally worse.
• End-of-life: newsprint is recyclable/compostable but generates daily paper waste; the e-reader becomes e-waste with hazardous components. Per year, newsprint waste volume is large, but the e-reader poses a concentrated hazardous-waste problem.

(iv) Stage of greatest impact for each: for newsprint, the recurring raw-material/manufacturing (paper and printing) plus daily distribution; for the e-reader, the one-time manufacturing of the device (amortized over a year of use). The e-reader is generally preferable if kept and used daily for a long period, since its fixed manufacturing burden is spread over thousands of editions.

(e) Definitions (any two)

Ecological footprint: the biologically productive land and water area needed to supply consumption and absorb waste. Cap and trade: a market system with a fixed emissions cap and tradable allowances, achieving reductions at least cost. Externalities: costs/benefits borne by third parties and not reflected in market prices.