Key Idea: Sustainability at HL is about reading the ledger and ranking the interventions. Digital systems sit on both sides of the climate account, and the intervention closest to manufacturing beats the one that is easiest to talk about.
Paper 1 Section B
- Extended response on climate, resources or waste
- Concepts — systems, change, values — named explicitly
- Named cases rather than general environmental claims
Paper 3
- Recommend a measure for the statement's situation
- Justify it by ranking against the alternatives
- State its limits, then conclude
Everywhere else
- 4.3: environmental contexts are the SL version
- 2.6: rebound is a feedback loop with a name
- 4.2: supply chains separate value from cost
The climate ledger
| Adds | Saves and enables |
|---|---|
| Electricity for data centres | Journeys not made |
| Emissions from making devices | Buildings heated only when used |
| Water for cooling | Grids balanced so less generation is wasted |
| Demand created by efficiency | Renewables, which cannot be balanced without it |
Variable wind and solar output cannot be scheduled, so balancing supply against demand requires continuous digital measurement and control. The grid that renewables need is a digital system, so the two are not opposed.
Rank before you recommend
By how close each gets to manufacturing
- Longer use — repairability, parts and a guaranteed support period. Strongest, because it reaches the stage that dominates.
- A second owner — refurbishment, so one manufacture serves two owners.
- Recover the materials — recycling, which acts after the emissions have already happened. Weakest, and most popular.
- And the enforcement question — a waste rule applies inside a border and the waste crosses it legally, so the duty has to fall on the manufacturer.
Important: Cheaper per use produces more uses, so a saving per use is not a saving overall. An efficiency measure has to be judged on the total rather than on the rate.
Exam-style questions
A committee is choosing between a recycling target, an export ban and a repair requirement to reduce a country's electronic waste. Recommend one and justify it.
🔒 Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Justify the claim that measures aimed at individual behaviour are the wrong response to the climate cost of digital technology.
🔒 Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Quick check
Why are renewables and digital systems not opposed? Variable output cannot be scheduled, so balancing needs continuous digital measurement and control.
What is rebound? Cheaper per use produces more uses, so a saving per use is not a saving overall.
The ranking rule Rank by how close an intervention gets to the manufacturing stage, because that is where the footprint is.
Why target the producer for waste? It is the one party the exporting country can reach, because it sells into that market and wants to continue.
Exam tips
- State the ranking before recommending. Paper 3 rewards the reasoning that led to a choice more than the choice itself.
- Aim at the large entry, not the popular one.
- Say who your measure reaches and why that party can be reached.