Climate change and Indian monsoon-
✓Monsoon in India has undergone several changes over the years, especially on account of climate change.
✓A shift in the track of monsoon systems, like low pressure and depression travelling south of their position and flash floods are a result of this change.
● Effect of climate change:
✓Intense and frequent extreme unprecedented rainfall over the places which once struggled to record even normal monsoon rains.
✓Threat on food security.
✓The IMD has clearly sighted that 2022 has seen the second highest extreme events since 1902.
● Reasons for rainfall variability:
✓Persistence of intense La Nina conditions,
✓Abnormal warming of East Indian Ocean
✓Negative Indian Ocean Dipole (IOD)
✓Southward movement of monsoon depressions and lows
✓Pre-monsoon heating over the Himalayan region
Excess and deficit rainfall
conditions
✓States such as Madhya Pradesh, Gujarat, Rajasthan and parts of Maharashtra have been recording excess rainfall this season.
✓These changes are believed to continue to propel extreme weather events over the entire South Asian region.
✓Entire South Asia has been reporting a series of extreme weather events.
✓Bangladesh, Pakistan and India have battled severe floods.
✓China is reeling under massive drought conditions.
● Rice production:
✓This year, the monsoon was potentially influenced by La Nina also — the cooler than usual Pacific conditions.
✓It impacted rice production which formed a significant share of more than 50% of total food grain production during this period.
✓Due to southward movement of majors, Bihar, West Bengal and Uttar Pradesh, which account for a third of the country’s total rice production, have been highly deficit.
● Impact of Uneven distribution of rain:
✓Rise to pest attacks and diseases
✓Impact on the quality of the grain
✓Variation in the nutrition value
✓Heat stress and affect on plant physiological processes
✓Spikelet sterility, non-viable pollen and reduced grain quality
✓Drought reduces plant transpiration rates
✓Can cause leaf rolling and drying
✓Reduction in leaf expansion rates and plant biomass
● Conclusion:
✓Research indicates that monsoon became less frequent but more intense in India during the latter half of the 20th century.
✓Scientists and food experts believe that a better rainfall scenario could have helped increase the harvest.
✓However, India’s rice producers and consumers are being affected negatively with these unprecedented changes which are also raising concerns over food security.
