Effect of GHG Emission on monsoon
Q. Which of the following are reasons for weakening of monsoon and erratic pattern of it?
1) Increased greenhouse gas (GHG) emissions
2) Atmospheric aerosols
3) Land-use changes- Published on 21 Apr 16a. 1, 2
b. 1, 3
c. 2, 3
d. All of the above
ANSWER: All of the above
- The monsoon is mainly driven by thermal contrast between the Indian subcontinent and the adjoining ocean.The South Asian Monsoon has been weakening since the 1950s with an increased incidence of extreme rainfall events.
- It is attributed to increased greenhouse gas (GHG) emissions, atmospheric aerosols and land-use changes.
- Land use changes includes deforestation.
- The reduction in land-sea temperature contrast is also attributed mostly to a strong warming in the Indian Ocean. This is due to global warming.
- Greenhouse gases trap the heat over land and sea and result in both the land and sea being warm, that is the thermal contrast is greatly reduced. This leads to a weakening of the monsoon circulation and the result is a weakened monsoon.
- However, a warmed up atmosphere can hold more moisture and this situation can result in heavy rainfall over some regions.
