IDENTIFYING WILDERNESS

Mapping intact ecosystems can be done on a global scale using high resolution satellite imagery to assess forest extent, but this approach fails when assessing desert biomes, or indeed any areas that are not forests.

To circumvent this, James Watson and his team used a kind of reverse assessment where wilderness is defined as contiguous areas of land or ocean greater than 10,000 hectares that are deemed free of a number of indicators of human pressures.

Maps created in 2016 for terrestrial areas and in 2018 for ocean areas are based on Human Footprint maps created in the 1990s and updated today.

The advantage of mapping human pressures is that you capture actions which have the potential to damage nature and therefore drive changes in the ecological system, rather than just presence or absence of an ecological state.

Human pressures mapped in terrestrial environments include built environments; crop lands; pasture lands; population density; night-time lights; railways; major roadways; and navigable waterways. Pressures for determining ocean wilderness included sixteen indicators such as shipping lanes, fertiliser run off and fisheries.