OPSC Prelims-2022, GS: Answer Key - Download

Daily Current Affairs

Warm Winter Season

Syllabus- Environment and Ecology [GS Paper-3]

Context- The India Meteorological Department (IMD) has predicted a warm winter season across the country and says the minimum temperature may remain above normal.

Key Highlights 

  • The sudden winter warming in 2023 is due to several factors – climate change,  strong El Nino, sea ice not renewed after the winter, reduced aerosol emission and increased solar activity.  
  • In September, the climate warming exceeded 1.5 °C and two months later it exceeded 2°C. The world is currently 2°C warmer than  pre-industrial times. 
  • According to recent IMD observations, the region has remained  above the 2.4 °C threshold. This is further exacerbated by regional factors such as the Western Disturbance and a cyclone in the Bay of Bengal, with above-normal minimum temperatures making it a warm winter for the country.  

Factors related to winter warming: 

    • Climate change: greenhouse gases trap heat, so the Earth is not a snowball. 
      • But the 2 trillion tons of fossil carbon in the atmosphere trap more heat and  will continue to do so until countries around the world stop burning fossil fuels for heat or electricity. 
      • Human emissions and other activities contributed to about 1.2 °C of warming.  
    • El Nino: The climate cycle of Pacific El Nino-Southern Oscillation (ENSO) has the greatest influence on climate.  
      • El Nino will  peak in the next two months, but its effects could continue through 2024, when the global average temperature will increase by 0.15°C.  
  • El Nino condition: 
      • Warmer than normal sea surface temperature was measured in the equatorial Pacific Ocean.
      • During the El Nino phase, the seas of South America warm up. This, in turn, generally raises the average  temperatures  of the Earth. 
  • Antarctic Sea Ice Melting: Arctic sea ice decline and failure to recover is contributing to winter warming. Usually, the circle of frozen sea water around the ice continent reaches its greatest extent in September.  
    • In summer, darker water is exposed, which absorbs more heat. This means more heat goes into the oceans instead of back into space. 
  • Increase in solar activity: Solar maximums have been predicted for 2025 and there is a clear increase adding more heat to the atmosphere. However, the effect is only about 0.05°C, or about a third of  El Niño. 
  • Volcanic activity: Volcanic eruptions generally cool the planet because their large aerosols block sunlight. But the biggest volcanic eruption of this century near Tonga in 2022 did the opposite. 
    • That’s because the Hunga Tonga-Hunga Ha’apai volcano was under the sea, and its explosive force vaporized huge amounts of seawater—and water vapor is a greenhouse gas. 
    • This is estimated to add 0.035 °C over about five years. 
  • Reduction of aerosol emissions: In 2020, new international shipping regulations came into force requiring low-sulfur fuels, reducing sulfur dioxide emissions by approximately 10%. 
    • Atmospheric aerosols trap heat and increase atmospheric warming. However, the effect is small and increases warming by an estimated 0.05 °C by 2050. 

Consequences of winter warming: 

  • Extreme heat: Warming below 4°C will set new high temperatures along the west coast and southern India, with significant impacts on agriculture. 
  • Variable rainfall: A 2°C increase in global average temperature will make India’s summer monsoon highly unpredictable. 
    • If warming is 4°C, an extremely wet monsoon  is predicted to occur every 10 years by the end of the century, which is currently only possible once every 100 years. Dry years are expected to be drier and wet years wetter. 
  • Drought: Drought is expected to become more common, especially in the regions of Northwest India, Jharkhand, Orissa and Chhattisgarh. Due to extreme heat, harvests are expected to decline significantly  by the 2040s.  
  • Agriculture and food security: Seasonal water shortages, rising temperatures and seawater intrusion threaten crops and the country’s food security. 
    • If warming is below 2 degrees by the 2050s, the country could import more than twice as much grain as it would need without climate change. 
  • Melting glaciers: As temperatures warm up to 2.5°C, melting glaciers and loss of snow cover over the Himalayas are likely to threaten the stability and reliability of northern India’s predominantly glaciated rivers, particularly the Indus and Brahmaputra.  
  • Sea level rise and related problems: If India is near the equator, the sea level of the peninsula will rise much more than at higher latitudes. 
    • Sea level rise and storm surges would lead to saltwater intrusion into coastal areas, affecting agriculture, degrading groundwater quality, contaminating drinking water and potentially increasing outbreaks of diarrhea and cholera because the cholera bacterium survives longer in saltwater. 
  • Migration and conflict: Impacts of climate change  on agriculture and livelihoods may increase the number of climate refugees.  

What does a warmer winter mean for Indian states? 

  • The higher temperature is likely to cause melting of glaciers in mountainous regions like Jammu and Kashmir, Himachal Pradesh, Arunachal Pradesh and Uttarakhand.  
  • On the other hand,  the plains of Rajasthan, Haryana and Punjab are expected to have a 75% chance of above normal maximum temperatures, which would make hotter days common over a much larger area. 
  • The southern Indian states are expected to experience cooler days and nights compared to the northern hills and plains.

Source: Indian Express

Practice question:

Q. During an El Niño event, which weather patterns are often observed?
  1. Intense hurricanes in the Atlantic.
  2. Prolonged drought conditions in some regions.
  3. Enhanced monsoon rains in Southeast Asia.
  4. Decreased temperatures in the Northern Hemisphere.
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