Answer:
a. Desertification
Step-by-step explanation:
Desertification refers to the process in which a fertile piece of land is converted into deserts. This process occurs due to unavailability of water for crops and unwise cutting of tree in large quantity. Due to global warming, many areas turns into deserts and no vegetation is present there. Due to this Desertification process, agricultural land is useless which directly impact on the economic condition of the region due to unavailability of food for humans and goods for export to earn foreign exchange.