Land degradation
Land degradation is a process in which the value of the biophysical environment also biochemical environment is affected by a combination of human-induced processes acting upon the land.[1] It is viewed as any change or disturbance to the land perceived to be deleterious or undesirable.[2] Natural hazards are excluded as a cause; however human activities can indirectly affect phenomena such as floods and bush fires.
Expert projections suggest that land degradation will be an important theme of the 21st century, impacting agricultural productivity, biodiversity loss, environmental change, and its effects on food security.[3] It is estimated that up to 40% of the world's agricultural land is seriously degraded.[4]
According to the Special Report on Climate Change and Land of the Intergovernmental Panel on Climate Change, "About a quarter of the Earth's ice-free land area is subject to human-induced degradation (medium confidence). Soil erosion from agricultural fields is estimated to be currently 11 to 20 times (no-tillage) to more than 100 times (conventional tillage) higher than the soil formation rate (medium confidence)."[5]
The United Nations estimate that about 30% of land is degraded worldwide, and about 3.2 billion people reside in these degrading areas, giving a high rate of environmental pollution.[6] About 12 million hectares of productive land – which roughly equals the size of Greece – is degraded every year. This happens because people exploit the land without protecting it.[7][8] The United Nations Sustainable Development Goal 15 has a target to restore degraded land and soil and achieve a land degradation-neutral world by 2030.[9]
In addition to the usual types of land degradation that have been known for centuries (water, wind and mechanical erosion, physical, chemical and biological degradation), four other types have emerged in the last 50 years:[11]
Overall, more than 36 types of land degradation can be assessed. All are induced or aggravated by human activities, e.g. soil erosion, soil contamination, soil acidification, sheet erosion, silting, aridification, salinization, urbanization, etc.
Public awareness and education[edit]
Increasing public awareness about the importance of land conservation, sustainable land management, and the consequences of land degradation is vital for fostering behavioral change and mobilizing support for action. Education, outreach campaigns, and knowledge-sharing platforms can empower individuals, communities, and stakeholders to adopt more sustainable practices and become stewards of the land.
Sensitivity and resilience are measures of the vulnerability of a landscape to degradation. These two factors combine to explain the degree of vulnerability.[10] Sensitivity is the degree to which a land system undergoes change due to natural forces, human intervention or a combination of both. Resilience is the ability of a landscape to absorb change, without significantly altering the relationship between the relative importance and numbers of individuals and species that compose the community.[20] It also refers to the ability of the region to return to its original state after being changed in some way. The resilience of a landscape can be increased or decreased through human interaction based upon different methods of land-use management. Land that is degraded becomes less resilient than undegraded land, which can lead to even further degradation through shocks to the landscape.