Question

Direct and indirect loss of natural area from urban expansion

Answer 1

Explanation:

Global losses of natural area are primarily attributed to cropland expansion, whereas the role of urban expansion is considered minor. However, urban expansion can induce cropland displacement, potentially leading to a loss of forest elsewhere. The extent of this effect is unknown. This study shows that indirect forest losses, through cropland displacement, far exceed direct losses from urban expansion. On a global scale, urban land increased from 33.2 to 71.3 million hectares (Mha) between 1992 and 2015, leading to a direct loss of 3.3 Mha of forest and an indirect loss of 17.8 to 32.4 Mha. In addition, this urban expansion led to a direct loss of 4.6 Mha of shrubland and an indirect loss of 7.0 to 17.4 Mha. Guiding urban development towards more sustainable trajectories can thus help preserve forest and other natural area at a global scale.