A country’s per capita footprint is measured by first calculating the footprint of a range of food and fibre. For example, the sugar footprint is calculated by adding Australian sugar production to the amount of sugar we import. This tells us our sugar consumption. Then we calculate the land area needed to produce that sugar. To take into account the sugar imported, we take the world average land requirement for growing sugar in tonnes per hectare. Then we divide that area by the Australian population to find out how much land we each need for sugar production, noting whether it’s arable land, pasture, forest or sea. This calculation is done for a range of other foods and fibres. But different foods need different types of land. Sugar needs arable land. This is taken into account by using a multiplier for arable land, pasture, forest and sea. For example, arable land is 2.8 times more productive than world average land. So we take the per capita food footprint of a country for food grown on arable land and convert it to a world average footprint by multiplying it by 2.8. The factor for pasture is 0.5, forest 1.1 and sea 0.2. Next, we add on the areas needed for energy use and cities. Energy area is the area needed to sequester the CO2 from our energy use (see the table above). Cities are factored in because built up land is unavailable for biological production. Now we have a figure in hectares showing a per capita footprint. Exhaustive? But we’re not finished yet! Now we look at bio-capacity so we can find out if a country is living within its means. We’ve already factored in the different values of various land types. But each country doesn’t have an equal amount of arable land, pasture, forest and sea. To adjust for this and to allow global comparison, the productivity of a country’s arable land is compared with the global average productivity of arable land, then scaled up or down. For example, Italy’s arable land is 1.49 times more biologically productive than world average arable land. So if Italy has 0.21 hectares of arable land per person, we multiply it by 1.49 to reflect that country’s bio-capacity. Then we do the same for pasture, forest and sea. Now we have a world equivalent bio-capacity for each country which can be compared with the per capita footprint we calculated earlier. We subtract 12% for biodiversity, restricting our appropriation of nature to 88%. Many countries are in deficit. Some are in surplus. The world is in deficit. What can we learn? The affluent (us) must reduce the size of our footprint very soon.