Daily Sun | 05 April 2023

In general terms, climate change does not introduce many additional or unanticipated risks but it will intensify some existing relationships between the environment and human wellbeing, making human life and livelihood more difficult and dangerous than they are now. Only a few examples of extreme weather occurrences include droughts, flooding, waterlogging, cyclones and tsunamis, tornadoes, thunderstorms, river/coastal erosion, landslides, salty water intrusion, hailstorms and other natural disasters. These natural disasters have the potential to have profound effects on socioeconomic conditions, agricultural output, and human and animal health.

Bangladesh has seen more than 200 environmental disasters in the past three decades. The 181 nations are evaluated by the World Risk Index 2021 (WRI 2021) based on their vulnerability to natural disasters. This includes practically the entire global population. Bangladesh is the third-highest risk country in Asia among the top five countries, according to the WRI 2021.

Bangladesh experiences thunderstorms as a part of its seasonal climate. It has become a very frequent environmental disaster since 2015. Thunderstorms are most common during the pre-monsoon season (March to May) and post-monsoon season (October to November) when the weather is warm and humid. However, thunderstorms can occur at any time of the year if it gets favorable weather conditions. It’s worth keeping in mind that thunderstorms can change from year to year in size, frequency, and location based on a variety of possible factors like climate, moisture, wind, and other meteorological patterns.

Though, thunderstorms and lightning are a natural atmospheric phenomenon that occurs when warm, moist air rises and cools, causing water droplets to condense and form clouds. The movement of air within the cloud can create electrical charges, which can build up and result in lightning. But several factors can influence the intensity of thunderstorms. As thunderstorms are fuelled by warm and humid air, the higher the temperature, the more energy is available for the storm, which can increase its intensity and lighting. Also, high levels of humidity can contribute to the formation of larger and more powerful thunderstorms. The amount of moisture present in the air can make change into the density of the thunderstorm and lighting. The moisture delivered to the atmosphere also, considerably dependent on the temperature of the water. Then, wind shear refers to the change in wind speed and/or direction with height. Strong wind shear can cause thunderstorms to rotate and exaggerate. It led to more severe weather. Additionally, the regional topography may have an impact on how powerful a thunderstorm is. For example, having the effects of atmospheric circulation lifting might cause thunderstorms to originate over mountainous regions to become more powerful. Instability in the atmosphere, which occurs when warm air rises rapidly and cold air sinks, can lead to the formation of thunderstorms. Moreover, unstable conditions can lead to stronger thunderstorms. According to various sources, the country’s highest number of deaths from lightning occurred in the Kishoreganj, Sunamganj, and Brahmanbaria districts. The thunder and lightning can interact with other weather systems, such as cold fronts or warm fronts, which can enhance or suppress their intensity depending on the circumstances. These are just a few of the factors that can influence the intensity of thunderstorms.

However, pollution has an indirect impact on thunderstorms by affecting the overall climate and weather patterns. For example, air pollution can indirectly influence lightning and thunder by affecting the overall atmospheric conditions that are necessary for their occurrence. As the air pollution can affect temperature patterns by trapping heat near the surface of the Earth. This can lead to the formation of temperature inversions, where the air near the surface is cooler than the air higher up in the atmosphere. The temperature inversions can inhibit the formation of thunderstorms by preventing warm, moist air from rising. This creates atmospheric instability by altering the balance between warm and cool air masses. This can lead to changes in the vertical motion of air within the atmosphere, which can lead to the formation of thunderstorms. Dhaka city is the top of the air polluted city according to Air Quality Index 2022 and the thunderstorm frequency is also high in the same city according to the report on Bangladesh Disaster-related Statistics 2021.

According to media reports, in the past several years, many people have been killed or injured by lightning strikes across the country, especially during the monsoon season. In 2016, thunderstorm and lightning strikes killed at least 26 people, mostly farmers, in different parts of the country. Then in 2018, at least 15 people were killed and many others injured due to lightning strikes. In 2019, lightning strikes killed 193 people and injured 139 others across the country, according to the Disaster Management and Relief Ministry of Bangladesh. In 2020, lightning strikes killed at least 126 people and injured many others in different parts of the country, according to media reports citing government sources. Between 2011 and 2020, lightning strikes killed more than 1,800 people and injured over 2,000 others in Bangladesh, according to data from the Bangladesh Meteorological Department. Till October 2021, lightning strikes in Bangladesh have claimed the lives of at least 329 individuals. According to the number of deaths caused by lightning, 98.52 percent were common people. All of the deaths happened in open spaces. Among them, the mortality rate for those working in agriculture is 74%. 

Due to climate change floods, cyclones, storm surges, river bank erosion, droughts, saline water intrusion, thunder storm and tsunamis all became very common occurrences in Bangladesh. The lightning strike is highly unpredictable but in some countries there have lightning detection systems that can detect lightning strikes and provide warnings to the public. These systems use a network of sensors that can detect the electromagnetic signals produced by lightning and determine the location and intensity of the strike. The department of climate science of Dhaka University already created this device but there is no widespread use of it. Our meteorological department need to develop this kind of system for public safety measures. But our national weather service’s provide alerts and warnings for severe weather conditions, including thunderstorms and the expected severity, timing, and location of the storm. It’s important to take appropriate safety measures during thunderstorms to reduce the risk of injury or death. Still, it’s important to note that thunderstorms are a natural phenomenon that is primarily influenced by weather patterns and atmospheric conditions, rather than pollution as an indirect influencer.