People rank environmental actions badly, and health care is no exception — the visible action and the large action are almost never the same one. Put six real hospital measures in order of climate impact and check your intuition against the evidence. Then take a single life-cycle question, move the system boundaries, and watch the correct answer change.
1 · Rank by climate impact — biggest lever at the top
Ranking by impact, not by ease. Two of these six are near-instant policy changes with no clinical downside, and one of them is the flagship of most hospital green committees while being close to the bottom of the list.
3 · Life-cycle lab: one surgical gown, two answers
Uses before the reusable gown is retired75
1 use150 uses
Carbon intensity of the laundry’s electricity400 g
20 g/kWh800 g/kWh
Move the system boundary
Life-cycle verdict
Reusable
Disposable
Illustrative model, transparently crude. Reusable gown manufacture is amortised over the number of uses you set; laundering is charged at about 1.15 kWh per gown against the grid intensity you set. Real assessments are far more detailed, and that is the point: the numbers below move because you moved the assumptions, not because the physical world changed. Any life-cycle claim that skips its boundary conditions should be treated with suspicion.