Desertification is the gradual degeneration of land productivity and quality caused due to climate change or anthropogenic activities. It is not the extension of deserts but a reduction in capacity of land to provide services.
Desertification is caused by multiple factors like Overgrazing, groundwater exploitation, Unsustainable farming etc.
Why desertification doesn't have climatic boundaries:
1. Primarily associated with Arid regions, but increased climatic pressure has extended it to semi-arid and sub-humid regions.
2. The northward movement of arid lands is its prominent indicator. E.g.: Southern Punjab showing conditions similar to the dry Rajasthan.
3. Climate change has impacted rainfall duration and volume, further extending the dry regions.
4. Land degradation is a global concern- from Canada to the Kalaharis of Africa.
5. Climate activities like ocean currents, trade winds influence precipitation, leading to erosion either via excess (water erosion) or deficiency (wind erosion).
Desertification would lead not only to erosion of soil and productivity loss, but also economic crisis and food security challenges. It is thus necessary for a global action to fight the menace that knows no national or climatic boundaries.