Impact of Climate Change on Monsoon

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    In Context

    • Monsoon in India has undergone several changes over the recent years, especially on account of climate change. 

    More about the news

    • The Indian Meteorological Department (IMD) has sighted that 2022 has seen the second highest extreme events since 1902. 
      • Persistence of intense La Nina conditions, 
      • The abnormal warming of East Indian Ocean, 
      • Negative Indian Ocean Dipole (IOD), 
      • Southward movement of most of the monsoon depressions and lows and 
      • Pre-monsoon heating over the Himalayan region are melting glaciers. 
      • This is a very complex mix.
    • Recent research indicates that monsoon rainfall became less frequent but more intense in India during the latter half of the 20th century. 

    Indian Monsoon 

    • The monsoons are experienced in the tropical area roughly between 20° N and 20° S. Following are a few reasons for the formation of monsoons in the Indian Subcontinent:
      • The differential heating and cooling of land (Indian subcontinent) and water (Ocean around subcontinent).
      • The shift of the position of the Inter-Tropical Convergence Zone (ITCZ) in summer.
        • The Inter Tropical Convergence Zone (ITCZ,) is a broad trough of low pressure in equatorial latitudes. This is where the northeast and the southeast trade winds converge. This convergence zone lies more or less parallel to the equator but moves north or south with the apparent movement of the sun
      • The presence of the high-pressure area, east of Madagascar over  the Indian Ocean.
      • The Tibetan plateau gets intensely heated during summer, which results in strong vertical air currents.
      • The movement of the westerly jet stream to the north of the Himalayas and the presence of the tropical easterly jet stream over the Indian peninsula during summer.

    Effects of Monsoon on Indian Subcontinent

    • The Indian landscape, it’s animal and plant life, its entire agricultural calendar and the life of the people, including their festivities, revolve around this phenomenon.
    • Agriculture:
      • It accounts for 18 percent of India’s growth domestic product (GDP) and employs around half of its total workforce. The monsoon rains are the main source of water for 55 percent of the country’s arable land. This means the rains are crucial — not only for India’s farmers but for its economy as a whole.
    • Rivers:
      • The monsoon brings water and sediment not only to Indian rivers but also to rivers in China, Bangladesh, etc. 
    • Festivals:
      • There are numerous traditional fasts and festivals celebrated during the wet season, some of them are Ganga Dussehra, Rath Yatras, Kanwarias, Janmashtami, Barsha Mongol Ramadan and Splash fairs are one of the most important parts of all monsoon festivals.

    Impact of Climate Change on monsoon

    • Overall:
      • 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. 
    • And these changes spell intense and frequent extreme unprecedented weather events over the places which once struggled to record even normal monsoon rains.
    • Shift of monsoon weather systems:
      • Usually, monsoon systems move across Northwest India giving rains over the region there. 
      • But this year most of the monsoon weather systems have been travelling across central parts of the country, changing the area of rainfall. 
        • As a result, States such as Madhya Pradesh, Gujarat, Rajasthan and parts of Maharashtra have been recording excess rainfall this season. 
        • West Bengal, Jharkhand, Bihar and Uttar Pradesh are experiencing the worst monsoon season of the century.
        • Experts believe that these changes are here to stay, which would continue to propel extreme weather events over the entire South Asian region.
      • Worldwide implications:
        • During the last six months, entire South Asia has been reporting a series of extreme weather events. 
        • While Bangladesh, India and Pakistan have battled severe floods, China is reeling under massive drought conditions.
    • Rice production:
      • One of the major impacts of changes in track of monsoon systems can be seen on kharif crops, particularly rice production. 
        • They form a significant share of more than 50% of total food grain production during this period.
      • The state experiencing monsoon deficit, West Bengal, Bihar, Jharkhand and east Uttar Pradesh are all rice-producing states.
    • Overall impacts on crops:
      • These uneven distribution rains along with increasing temperatures and humidity give rise to pest attacks and diseases. 
        • This will, in turn, impact the quality of the grain as well as the nutrition value may vary. 
      • According to a study, ‘Climate change, the monsoon, and rice yield in India’, very high temperatures (> 35°C) induce heat stress and affect plant physiological processes, leading to spikelet sterility, non-viable pollen and reduced grain quality. 
      • Drought, on the other hand, reduces plant transpiration rates and may result in leaf rolling and drying, reduction in leaf expansion rates and plant biomass, immobilisation of solutes and increased heat stress of leaves.

    Way Ahead

    • Slow onsets can still be taken care of through adaptation and resilience ideas but these kinds of big events are very difficult to cope with. 
      • That is where the main issue lies as the country would then have to divert development money to climate finance to combat climate change.
    • India’s hundreds of millions of rice producers and consumers are being affected negatively with these unprecedented changes which are also raising concerns over food security.
      • Short-term actions & solutions:
        • In UP, the Agriculture Meteorology division has advised carrying out the transplantation of rice and suggested the use of short-duration rice varieties. 
          • Experts have encouraged the cultivation of red gram.
          • Farmers are also recommended to opt for inter-cropping.
        • For farmers in Jharkhand, the Agrimet has suggested adopting measures to conserve moisture in the soil. 
          • No sowing is advised until there is 50 to 60mm rainfall and sufficient moisture for at least three consecutive days. 
        • Short-duration rice, millet, maize, and arha

    Source: TH

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