Triple-dip La Nina

In Context

  • Recently various weather agencies like WMO and UN predicted a rare ‘triple-dip’ La Nina in 2022.

More about the news

  • World Meteorological Organization (WMO):
    • WMO recently predicted that La Niña conditions, which involve a large-scale cooling of ocean surface temperatures, have strengthened in the eastern and central equatorial Pacific with an increase in trade winds.
    • Experts say we have a high chance of experiencing our third La Niña year in a row, the first time since the year 2000.
  • UN weather agency:
    • The agency is also predicting that the phenomenon known as La Niña is poised to last through the end of this year.
  • Challenges ahead:
    • It means three straight years of La Nina effect on climate patterns like drought and flooding worldwide.
    • Its cooling influence is temporarily slowing the rise in global temperatures, but it will not halt or reverse the long-term warming trend.

La Nina & ENSO

  • About:
    • La Niña is a natural and cyclical cooling of parts of the equatorial Pacific that changes weather patterns worldwide, as opposed to warming caused by the better-known El Niño, an opposite phenomenon.
    • La Niña and trade winds:
      • Due to the cooler temperature, the trade winds above the sea surface change in character because of a difference in the wind pressures. 
      • This change in the character of the trade winds is then carried all around the world affecting different regions in different ways. 
    • El Niño Southern Oscillation (ENSO):
      • Together El Niño, La Niña and the neutral condition are called ENSO, which stands for El Niño Southern Oscillation.
      • These oscillations have one of the largest natural effects on climate.

  • Outcomes of La Nina:
    • Many regions become colder and wetter, while many others become hotter and drier
  • Causes of prolonged La Nina: 
    • Human-induced climate change amplifies the impacts of naturally occurring events like La Niña and is increasingly influencing our weather patterns.
    • Extreme El Niño and La Niña events may increase in frequency from about one every 20 years to one every 10 years by the end of the 21st century under aggressive greenhouse gas emission scenarios.

Concerns

  • For India:
    • No spring season for India:
      • La Nina usually brings wet and cold winter and spring seasons for India, but this time large parts of India do not experience a spring season at all. 
      • This happens as a north-south pressure pattern, which usually forms over India during the winter season and dissipates by spring, continuing into March and April during La Niña years. 
    • Prolonged monsoons and floods in India:
      • India can experience a prolonged monsoon season for the third year in a row. 
        • The monsoon seasons of 2020 and 2021 were also extended, leading to an increase in extreme rainfall events during the period.
      • It may lead to subsequent floods as seen in many states in the last two years. 
  • In the other parts of the world
    • Drought conditions:
      • The ongoing drought conditions in 40 percent of the United States, the years-long drought conditions in the Horn of Africa and southern South America would also likely continue and become more intense due to the continuation of the La Nina.
        • It also leads to agricultural losses in this part of the world.
    • Hurricanes:
      • It could also form an above-average hurricane season for the Atlantic Ocean, with a 65 percent probability. 
    • Heat waves & wildfires:
      • This condition could lead to devastating and unpredictable consequences for India and many other regions around the world in particular through more intense heat waves and drought and the associated risk of wildfires.

Way Ahead

  • Mitigation:
    • The current atmospheric carbon dioxide (CO2) concentrations are higher than at any time in the last two million years. 
    • To align with a 1.5°C target of limiting warming, global CO2 emissions must reach net zero around 2050, with global GHG emissions reaching net-zero 15-20 years later. 
    • A delay of 15-20 years in either net-zero CO2 or net-zero GHGs implies limiting warming to 2°C rather than 1.5°C. 
  • Need to shift from the sensational to the strategic: 
    • In order to stabilise the rise in temperatures, two things have to happen:
  • Anthropogenic emissions must become net-zero and, 
  • In the interim, cumulative emissions cannot exceed a global carbon budget.
  • Adaptation: 
    • Adaptation can be understood as the process of adjusting to the current and future effects of climate change. 
    • India has a strategy to combat climate change under the National Action Plan on Climate Change formed with the integration of similar missions at the state level. 
    • Apart from that, India has also launched the Coalition for Disaster Resilient Infrastructure (CDRI). 
    • However, climate change would require international collective action for maximum impact
    • This is because safeguarding the climate is a global requirement and any strategy in silos will only have a limited impact.

Source: IE