Current output can rise while future productive resources deteriorate.
Growth is environmentally sustainable when its continuation does not rely on excessive resource depletion or environmental damage that undermines future wellbeing. Pollution can harm health and productivity, while damage to ecosystems can reduce future production and consumption opportunities. Investment and cleaner technology can improve the relationship between output and environmental pressure, but a lower pollution intensity per unit does not automatically mean lower total pollution. Evaluate the scale, persistence and reversibility of damage and the resources needed to sustain future output. Growth is not necessarily environmentally destructive, nor is every activity labelled green necessarily harmless.
- Sustainability
- Environmentally sustainable growth can continue without damage to resources or the environment undermining future wellbeing. More production today does not by itself show that the growth path can last.
- Intensity and scale
- Emissions intensity means emissions per unit of output. Total emissions = output x emissions intensity. Producing more can outweigh an improvement in how clean each unit is.
- Future consequences
- Resource depletion means using up natural stocks, such as fish or minerals. Depletion and pollution can damage health, ecosystems and the resources available for future production and consumption.
Cleaner per unit is not the whole result
Possible improvements
Cleaner processes, usable capital and innovation can reduce damage, but assess their full resource use rather than the label.
Relevant evidence
Check total emissions, how quickly renewable resources recover, where people are exposed and how long damage lasts. For example, lower emissions per unit do not settle whether nearby air is safe to breathe.
Worked example: Cleaner per unit, but more emissions overall
A factory produces 100 units with emissions of 10 units. After an efficiency improvement it emits 0.08 units per output unit, but production expands to 150 units. The emissions affect nearby residents.
- Initially emissions intensity is 10 / 100 = 0.10 per output unit. It falls to 0.08: each unit of output is produced with fewer emissions.
- Total emissions become 150 x 0.08 = 12, above the initial 10 because output expands faster than intensity falls.
- Residents may face greater total exposure despite the cleaner production method per unit. The health effect also depends on location, concentration and the pollutant.
- Assess total environmental impact and future productive resources, not only the efficiency label or GDP increase.
Watch out for this
If pollution per unit falls, total pollution must fall.
Total pollution depends on both output and pollution per unit. A scale increase can outweigh the intensity improvement.
Check your understanding
Output is 150 units and emissions intensity is 0.08 per unit. What are total emissions?
- 0.08 units.
- 8 units.
- 12 units.