How will El Niño impact Bangladesh’s climate and agriculture this year?

El Niño is a worldwide climate phenomenon characterised by the warming of surface waters in the equatorial Pacific Ocean, which exerts an influence on the ionosphere and overall climate of its surroundings. El Niño can trigger adverse effects on the monsoon season, leading to below-normal rainfall and prolonged droughts. 

The heightened risk of El Niño-induced dry weather conditions in 2023/24 could harm cereal production. In light of this situation, anticipatory planning to prepare for such events may benefit Bangladesh.

ENSO stands for El Niño-Southern Oscillation. It is a significant climate event that involves the interactions between the ocean and the atmosphere in the equatorial Pacific region. ENSO denotes the irregular and recurring fluctuations in sea surface temperatures and atmospheric pressure patterns, exerting substantial influences on global weather and climate patterns. 

ENSO comprises two primary phases – El Niño and La Niña. 

During El Niño, sea surface temperatures in the central and eastern Pacific Oceans become unusually warm, resulting in significant climate impacts worldwide. It causes warm weather during winter, leading to dry and inadequate summer monsoons. These effects encompass alterations in precipitation patterns, droughts, floods and shifts in storm tracks. 

On the other hand, during La Niña, the sea surface temperatures in the same region become cooler than average, and it can also result in distinct weather patterns across different regions. El Niña emerges at irregular intervals of approximately two to seven years. However, El Niño tends to occur more frequently than La Niña.

El Niño, with its global impact, also may affect Bangladesh significantly. Let's consider the World Meteorological Organisation's (WMO) forecast regarding the occurrence of an El Niño event as accurate. Bangladesh may experience below-average rainfall or irregular precipitation patterns in that case, and warmer conditions can bring droughts. 

As per the forecast by WMO, the active phase of El Niño commenced in July, and its effects are already being observed in the country. This is evident through extreme temperatures during the pre-monsoon period and the extraordinary occurrence of high temperatures even during the monsoon season. 

Moreover, Bangladesh is experiencing reduced rainfall in both pre-monsoon and monsoon periods. The intensification in extreme weather is accompanied by a gradual increase in the apparent temperature, making the conditions even more challenging for the populace. 

Similar patterns were observed in 2016 during the active phase of El Niño. This highlighted the significance of understanding and preparing for the impacts of this climate phenomenon on Bangladesh and its weather patterns. 

The agrarian economy of Bangladesh heavily relies on the monsoon for favourable yields. However, this year, El Niño is expected to disrupt the country's weather conditions, potentially affecting agriculture. 

The weather conditions of Bangladesh from April to July concerning temperature and rainfall were almost similar to the El Niño forecast. Insufficient rainfall during the monsoon season in Bangladesh has a profound impact on rain-fed staple crop production. 

Recent data from the Bangladesh Meteorological Department (BMD) reveals that the country experienced significantly lower rainfall and higher temperatures than the average of the last 30 years. Specifically, the rainfall was reduced by 65% in April, 42% in May, 18% in June and nearly 43% in July, a critical period for the rainy season. In the first week of August, 252mm of rainfall occurred, almost 60% compared to average rainfall. 

The average temperatures experienced an above normal temperature in the country from April to July.  The maximum temperatures experienced a steady rise over April, May, June and July, with increases of 2.2°C, 1.8°C, 1.8°C and 2.6°C, respectively. 

Conversely, the minimum temperatures exhibited a fluctuating pattern – a slight decrease of 0.1°C and 0.5°C in April and May, followed by an increase of 0.6°C and 1.2°C in June and July. These unusual weather situations from April to July this year have already challenged agricultural activities in Bangladesh.

During this year's El Niño occurrence, there could be a significant impact on rainfall, potentially affecting crops such as cereals, pulses, and others. The projected changes in rainfall patterns may result in severe heatwaves and drought conditions, adversely affecting crop growth and productivity. 

Insufficient rainfall may lead to a shortage of irrigation water, impeding crop germination, growth and development. Furthermore, the temperature rise can affect crop development, leading to reduced yields. 

Heat stress might become a concern, particularly for temperature-sensitive crops, posing a risk to overall productivity. El Niño can also impact the prevalence and distribution of pests and diseases. 

Additionally, increased humidity during El Niño can create an environment conducive to the growth of fungal diseases. According to FAO analysis, if an El Niño event materialises, it could lead to dry weather conditions impacting croplands, potentially resulting in adverse implications on crop yields in the 2023/2024 season. 

By ratifying localised contingency plans, Bangladesh can mitigate the potential impacts caused by El Niño. By closely monitoring climate patterns and predicting potential adverse weather events such as droughts, floods or extreme temperatures, the authority can provide timely information to farmers. 

However, the government should increase the allocation of resources to support agricultural research and development initiatives to develop climate-resilient crop varieties. The government should focus especially on drought and heat stress tolerance, innovative farming practices and efficient water management techniques. 

Strengthening early warning systems and fostering awareness among communities to link warnings with proactive actions is essential in preparing for and managing the impacts of El Niño. Ensuring that the extension workers are adequately trained and equipped to guide climate-smart farming techniques, crop management strategies, and pest and disease control measures is essential. This will help farmers adopt resilient practices and make informed decisions. 

The government can provide market support and facilitate market linkages for farmers. This includes establishing fair pricing mechanisms, improving market infrastructure and promoting value-addition and agro-processing activities. 

To have a clear understanding and awareness of the adverse effects and management process of weather variability and El Niño in crop production steps is essential. Finally, developing and implementing supportive policies is crucial for addressing the impact on the overall farm sector. 

Niaz Md. Farhat Rahman is a Principal Scientific Officer (Agricultural Statistician) and Coordinator of the Agromet Lab at Bangladesh Rice Research Institute (BRRI), Gazipur, Bangladesh. 

Disclaimer: The views and opinions expressed in this article are those of the author and do not necessarily reflect the opinions and views of The Business Standard.