The searing heatwave in Bangladesh over the past two weeks has led to some surreal sights being witnessed across the country. Some people were seen using the sunlight alone to fry eggs on their balconies, while others struggled to cross roads that had literally melted under the heat.
Load shedding and water shortages made the situation worse in some areas.
Abdul Hakeem, 55, works as a security guard near the Prime Minister's Office. He recently fainted from the heat after walking for 30 minutes by road to reach his workplace.
The security guard was taken to the National Institute of Cardiovascular Diseases (NICVD) for treatment, and he has been experiencing chest pain since regaining consciousness.
Hakeem told Dhaka Tribune that his vision became blurred, and he fell to the ground after completing the walk to his workplace. The doctor gave him an echocardiogram (ECG) and said his heart was fine, advising him to see a doctor of medicine at a nearby government hospital.
M Bulbul Kabir, emergency medical officer (EMO) of NICVD, said: “For the past 10 days, such patients have been coming to the emergency department, and we are sending them to the nearby government hospital because their chest pain is due to high temperature. As a result of being out in the hot sun, the body becomes dehydrated, and those who have blood pressure and diabetes are getting sick more.”
He added that the high heat was increasing the risk of strokes and heart attacks.
“We are receiving an increasing number of patients with dizziness, blurred vision, and chest pain. Many of these patients have never had such problems before,” the EMO further said.
According to ICDDRB, the number of hospital admissions of children with diarrhoea is currently normal, but the number will increase after Eid if the heat does not abate.
On April 15, Dhaka recorded its highest temperature in 58 years at 40.4 degrees Celsius.
According to experts, Bangladesh's daily maximum temperature usually ranges from 30 to 35 degrees Celsius during April, with occasional increases of up to 37 to 38. Some districts may witness temperatures of 40 degrees Celsius once or twice a month.
Preliminary analysis of weather and climate variables indicates at least three reasons for the record-breaking heat wave in the country, said Mostofa Kamal Palash, weather and climate researcher at the School of Environment and Sustainability of University of Saskatchewan, Saskatoon, Canada.
First, a large-scale atmospheric wave pattern called the Jet Stream has become stationary over the Indian subcontinent. The Jet Stream is a narrow band of fast-flowing wind current that flows from west to east between 5 km and 16 km above the ground surface and carries heat and moisture across the globe.
When a Jet Stream becomes stationary, and the wave crest (ridge) lies over an area, cold and dry air starts falling from the upper atmosphere and accumulates over land. These conditions can be compared to traffic jam conditions on the Dhaka-Tangail highway during the Eid festival, the weather expert explained.
When cold and dry air starts accumulating over land, the air above the ground surface becomes warmer because of compressional force. An upper air ridge also creates a high-pressure system over the surface, preventing air from forming clouds as it fails to rise to the upper atmosphere.
The upper air ridge acts like a pressure cooker pin. The heat from a pressure cooker cannot be released until the pin is released, and incoming solar radiation from the sun similarly cannot escape the troposphere (the lowest 12 km of the atmosphere) unless the ridge moves away from the sky of Bangladesh and India.
This ridge will move from Bangladesh and India when a western disturbance (currently sweeping over Iran and Pakistan) starts entering the Indian subcontinent. The western disturbance is expected to reach Bihar, West Bengal, and Bangladesh around April 21, likely bringing Nor-Westers, rain, hail, and severe lightning.
The second reason for the current heat wave is suppression of convective activity over the Bay of Bengal due to the Mason-Julian Oscillation. The Mason-Julian Oscillation is expected to be active again starting from April 20.
“Unfortunately, Bangladesh has lost a significant percentage of its natural landscape, including forest cover, water bodies, wetlands, etc. When an area consists of forest cover, water bodies, and wetlands, a significant portion of the sun's energy is used for evapotranspiration, through which the atmosphere cools like a person's body releasing heat through sweating. It is also known as evaporative cooling,” the expert said.
“Bangladeshi people have been facing these boiling conditions in recent decades because of the decreased natural landscape conditions. Needless to say, the chance is very high that Bangladesh will face such extreme heat wave-like conditions more often than before, both due to man-made reasons locally and due to global climate change,” he added.
Mohammad Milan, a 60-year-old CNG driver, now drives for only half the time that he usually does. He spends the entire time from noon to Asr prayers inside the air-conditioned mosque.
“My blood pressure has increased in this heat and I fell ill. As I cannot work as much, my income has come down to half, and I have barely made enough to pay for iftar for my family of four for the last 10 days,” he added.
Muhammad Abul Kalam Mallik, meteorologist at the Bangladesh Meteorological Department, said electronic devices such as ACs or air coolers reduce the temperature indoors, but they cause the outdoor temperature to increase.
“The temperature outside rises, which is actually bad for the environment. Besides, the number of diesel vehicles that are driven at night increases the pollution in the environment, which is responsible for warming the environment,” he further said.