La Nina Phenomenon and Global Temperature Trends

The World Meteorological Organization (WMO) has reported that the cooling La Nina phenomenon may develop in the equatorial Pacific Ocean over the next three months. However, this event is expected to be weak and short-lived. La Nina is part of the El Nino Southern Oscillation (ENSO) cycle, characterised by cooler-than-normal ocean temperatures in the central and eastern Pacific. This phase typically results in a temporary cooling effect on global average temperatures.

Current Climate Context

The year 2024 is projected to be the hottest on record, with global average temperatures surpassing a 1.5°C anomaly compared to pre-industrial levels. The WMO indicates there is a 55% chance of La Nina developing between December and February. If La Nina occurs, it will likely be followed by a return to ENSO neutral conditions. This fluctuation occurs within the broader context of human-induced climate change, which continues to elevate global temperatures and intensify extreme weather events.

Impacts of La Nina and El Nino

La Nina can temporarily cool global temperatures but is unlikely to counterbalance the warming effects of greenhouse gases. The presence of these gases has led to unprecedented weather patterns. Despite the potential emergence of La Nina, extreme weather events have become the new norm. Record-breaking rainfall and flooding have been observed globally, alongside hurricanes and typhoons that are rapidly intensifying due to higher ocean temperatures.

Regional Temperature Records

Recently, regions such as Southeast Asia and the Caribbean Islands have experienced higher temperatures. For example, Indonesia recorded its hottest night ever on Belitung Island, with a minimum temperature of 26.8°C. This marks a historic milestone as the area surpassed the 26°C threshold for the first time on record. Such anomalies are indicative of broader climatic shifts affecting seasonal patterns.

Future Projections

Looking ahead, the WMO warns that even if a La Nina event develops, its cooling impact will be insufficient to mitigate the ongoing rise in global temperatures. The interplay between natural climate phenomena and human-induced changes will continue to shape weather patterns and temperature trends in the coming years.

Questions for UPSC –

1. Examine the role of human-induced climate change in exacerbating extreme weather events globally.
2. Discuss in the light of recent climatic changes, the significance of the El Nino and La Nina phenomena in influencing global temperatures.
3. Critically discuss the implications of record-breaking temperatures on agricultural practices worldwide.
4. With suitable examples, discuss the relationship between ocean temperatures and the intensity of tropical cyclones.

Answer Hints:

1. Examine the role of human-induced climate change in exacerbating extreme weather events globally.

1. Human-induced climate change leads to increased greenhouse gas emissions, trapping more heat in the atmosphere.
2. Higher global temperatures contribute to more frequent and severe weather events, such as hurricanes, floods, and droughts.
3. Extreme weather patterns are becoming the new norm, impacting ecosystems and human livelihoods.
4. Climate change alters precipitation patterns, leading to either excessive rainfall or prolonged dry spells.
5. Vulnerability of communities increases, especially in developing regions, due to inadequate infrastructure to handle extreme weather.

2. Discuss in the light of recent climatic changes, the significance of the El Nino and La Nina phenomena in influencing global temperatures.

1. El Nino and La Nina are key components of the El Nino Southern Oscillation (ENSO) that influence global weather patterns.
2. El Nino typically leads to warmer global temperatures, while La Nina can have a temporary cooling effect.
3. Recent climatic changes show that even La Nina’s cooling impact is insufficient to counteract the warming from greenhouse gases.
4. The current trend indicates that 2024 may be the hottest year on record, despite potential La Nina development.
5. Both phenomena interact with human-induced climate change, complicating predictions of weather patterns and temperature fluctuations.

3. Critically discuss the implications of record-breaking temperatures on agricultural practices worldwide.

1. Record-breaking temperatures can lead to crop failures, reduced yields, and increased pest infestations.
2. Higher temperatures affect planting and harvesting seasons, disrupting traditional agricultural calendars.
3. Increased heat can lead to water scarcity, affecting irrigation and overall crop health.
4. Farmers may need to adapt by shifting to more heat-resistant crop varieties or changing farming practices.
5. Economic impacts include increased food prices and food insecurity, particularly in vulnerable regions.

4. With suitable examples, discuss the relationship between ocean temperatures and the intensity of tropical cyclones.

1. Warmer ocean temperatures provide more energy for tropical cyclones, leading to increased intensity and rapid intensification.
2. Hurricanes in the North Atlantic have shown trends of higher wind speeds and rainfall linked to elevated sea surface temperatures.
3. Typhoons in the Northwest Pacific also exhibit similar patterns, with record-breaking intensities observed in recent years.
4. Examples include Hurricane Harvey (2017) and Typhoon Haiyan (2013), both of which were fueled by warm ocean waters.
5. As ocean temperatures rise due to climate change, the frequency and severity of tropical cyclones are expected to increase further.