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.