Global Temperature Records and the Role of La Niña
Last month was the hottest January on record, with the global average surface air temperature reaching 1.75 degrees Celsius above the pre-industrial level (1850-1900 average). This was noted by Europe’s Copernicus Climate Change Service (C3S).
La Niña and Its Expected Impact
- La Niña is part of the El Niño Southern Oscillation (ENSO) which affects global weather patterns through changes in sea temperatures in the Pacific Ocean.
- The ENSO has three phases: warm (El Niño), cool (La Niña), and neutral.
- Typically, La Niña leads to a cooling effect on global temperatures due to stronger trade winds pushing warmer waters westward.
Unexpected Temperature Trends in January 2025
Despite La Niña conditions, January 2025 experienced high temperatures due to the following reasons:
- The La Niña cycle was weaker than expected, emerging later than anticipated in December 2024.
- The rate of increase in atmospheric carbon remained high, exacerbating warming.
- Reduction in aerosols due to clean air policies may have lessened the cooling effect they typically provide by scattering solar radiation.
Significance and Implications
This record-breaking warmth indicates a potential decline in the effectiveness of natural cooling phases like La Niña to mitigate rising global temperatures.
- Experts emphasize the need to drastically reduce greenhouse gas emissions to prevent further warming.
- In 2024, atmospheric greenhouse gas levels were the highest ever recorded, highlighting the urgent need for intervention.