Work out environmental impact score instantly with clear inputs, formula shown and shareable results.
A common environmental impact assessment method scores magnitude, spatial extent and duration to give a consequence value, then multiplies by probability. The result is banded to determine whether mitigation is essential, required or unnecessary. Scoring criteria must be defined explicitly for the scores to be defensible.
Impact score
Consequence = magnitude + extent + duration; impact score = consequence x probability
Environmental impact assessment methodologies and significance criteria are prescribed by regulation and guidance. Scoring must be undertaken by competent assessors.
Because a certain small impact and an unlikely catastrophic one should not score alike. Multiplying consequence by probability captures risk rather than mere magnitude.
No. They structure professional judgement rather than replace it. Transparency about the scoring criteria and reasoning matters far more than the arithmetic.