La Nina

In Context

• A recent study shows that the ongoing La Nina may become the longest on record.
  • This indicates a major shift in natural climatic patterns in a warming world.

More about the News

• There are chances that the current La Nina could continue through the southwest monsoon season, winter of 2022 and even early 2023.
• This is especially evidenced by La Nina’s strong continuation through the summer of 2022 and its involvement in the early, intense and extensive heatwaves in northwest and central India.
• What happens during the La Nina event?
  • During a La Nina event, cooler-than-average sea surface temperatures prevail over the east and the central Pacific Ocean. 
  • 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. 
  • Many regions become colder and wetter, while many others become hotter and drier. 
• The character of La Nina, an ocean-atmosphere event that usually brings down global temperatures, is changing.
• Cause: 
  • 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

• 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 did not experience a spring season at all. 
  • This happened as a north-south pressure pattern, which usually forms over India during the winter season and dissipates by spring, continued into March and April this year. 
• Prolonged monsoon and floods in India:
  • India can experience a prolonged monsoon season for the third year in a row, for instance. 
  • 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. 
• Drought conditions in the other parts of the world:
  • 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.
• 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 an 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: DTE