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Define the ratio and comparison
Denominators are positive; the relative-change identity additionally requires a positive emissions baseline.
Inspect the original counterexample
Prior emissions 100 and denominator 10 give intensity 10. Current emissions 120 and denominator 15 give intensity 8. Emissions rise 20%, denominator rises 50% and intensity falls 20%.
Define the denominator before comparing
If D is revenue measured in millions of a stated currency, intensity has mass per million revenue units. If D is physical production, the result has another unit and interpretation. Do not combine unlike denominators in a peer table.
Handle a zero numerator baseline honestly
When prior emissions are zero, both intensity levels can still be calculated, but percentage change relative to that zero is undefined. Report absolute change and the levels rather than assigning an invented 100% or 0% change.