The Human Footprint measures the cumulative impact of direct pressures on nature from human activities. Individual pressures were placed within a 0–10 scale and summed, giving a cumulative score of human pressure ranging from 0 to 50. A Human Footprint score below 3 indicates land which is predominantly free of permanent infrastructure, but may hold sparse human populations. A Human Footprint score of 4 is equal to pasture lands, and is a reasonable threshold of when land can be considered “human dominated” and species are likely to be threatened by habitat conversion. A Human Footprint score of 7 is equal to agriculture, above which a landscape will contain multiple pressures, for example agriculture with roads and other associated infrastructure, and is therefore highly modified by humans.
Details about the work are provided in the following paper: