What’s the news?
- According to a report by the World Meteorological Organization (WMO), the past seven years were the warmest on record, and 2021 did not see record-breaking temperatures because of a La Niña event at the start and end of the year. The average global temperature in 2021 was about 1.11 (± 0.13) °C above the pre-industrial level.
- The report comes as north, central and western India reel under an onslaught of pre-monsoon heat waves, with temperatures in March breaching century-old records.
- As per the report, four key climate change indicators such as greenhouse gas concentrations, sea level rise, ocean heat and ocean acidification have set new records in 2021.
- Extreme weather led to economic damage worth hundreds of billions of dollars and triggered shocks for food, water security and displacement that worsened in 2022.
- The world must act in this decade to prevent ever worsening climate impacts and to keep temperature increase to below 1.5°C above pre-industrial levels for which “Renewable” is the only path to real energy security, stable power prices and sustainable employment opportunities.
- The WMO report added that ocean surface temperatures were at a record high. The upper 2000m depth of the ocean continued to warm in 2021 and would continue to do so in the future, a change which is irreversible on centennial to millennial time scales.
- Some glaciers have reached the point of no return and this will have long-term repercussions in a world in which more than 2 billion people already experience water stress.
- The heat trapped by human-induced greenhouse gases will warm the planet for many generations to come. Sea level rise, ocean heat and acidification will continue for hundreds of years, unless means to remove carbon from the atmosphere are invented.
About La Nina
- La Nina is the “cool phase” of ENSO, a pattern that describes the unusual cooling of the tropical eastern Pacific.
- The surface winds across the entire tropical Pacific are stronger than usual, and most of the tropical Pacific Ocean is cooler than average. Rainfall increases over Indonesia (where waters remain warm) and decreases over the central tropical Pacific (which is cool). Over Indonesia, there is more rising air motion and lower surface pressure. There is more sinking air motion over the cooler waters of the central and eastern Pacific.
- The ENSO cycle is a scientific term that describes the fluctuations in temperature between the ocean and atmosphere in the east-central Equatorial Pacific.
- La Niña is sometimes referred to as the cold phase of ENSO and El Niño as the warm phase of ENSO. These deviations from normal surface temperatures can have large-scale impacts not only on ocean processes, but also on global weather and climate.