City's heat index 65% higher than national average, WB warns in first report on Bangladesh
Rising temperatures in Bangladesh are driving a surge in heat-related illnesses, resulting in 250 million lost workdays and an economic cost of up to $1.78 billion in 2024, according to a World Bank study released yesterday.
Since 1980, Bangladesh's maximum temperature has risen by 1.1°C, while the "feels like" temperature has jumped by 4.5°C. The country now ranks second globally for exposure to extreme heat.
During the same period, Dhaka's maximum temperature rose by 1.4°C, making the capital one of the world's most significant urban heat hotspots.
Speaking at the report's launch at a city hotel, Syeda Rizwana Hasan, adviser to the environment, forest and climate change ministry, said the findings provided vital scientific validation. "Now we need to spell out concrete measures for each agency to act on."
As temperatures rise, Bangladeshis face growing health problems -- persistent cough, heat exhaustion, diarrhoea, depression, and anxiety -- according to the report, the first of its kind focusing entirely on Bangladesh.
The study, titled An Unsustainable Life: The Impact of Heat on Health and the Economy of Bangladesh, analysed temperature and humidity data from 1976 to 2023, alongside two rounds of household surveys covering more than 16,000 people between January and June last year.
"Extreme heat is not just a seasonal inconvenience. Its impact is far-reaching. As we see in Bangladesh, the rising temperature is affecting our health and productivity, and the country's prosperity," said Jean Pesme, division director for Bangladesh and Bhutan at the World Bank.
"By building on its experience in climate adaptation and taking a coordinated approach across sectors, Bangladesh can address the heatwave impacts and maintain sustainable growth."
Dhaka has been hit the hardest, with its heat index rising 65 percent higher than the national average. Rapid urbanisation, population growth, and unplanned development, including the large-scale loss of green space, are driving the "urban heat island" effect.
The report says Dhaka lost 47 percent of its dense green cover between 1989 and 2020 as land was converted into built-up areas. Urban expansion accelerated after 1999, and by 2020 green spaces had shrunk to 5,600 hectares from 12,745 in 1989.
Between 2001 and 2017, Dhaka's total area grew by 19 percent, but the population rose by nearly 77 percent, sharply intensifying heat exposure. Green spaces, the report notes, are crucial for reducing heat intensity, improving air quality, lowering flood risk, and protecting public health.
The use of heat-trapping building materials is making conditions worse. Indoor air temperatures in South Asian cities can exceed outdoor temperatures by up to 4°C at night, particularly in tin-roofed homes, raising the risk of heat stress.
Rizwana noted that the Detailed Area Plan for Dhaka had been prepared years ago but was never finalised due to resistance from business groups. "The city should not be left in the hands of business interests; it should serve its dwellers," she said, calling for strict enforcement of environmental laws, protection of remaining green spaces, better city planning, and an overhaul of public transport to cut emissions and heat buildup.
Prof Sayedur Rahman, special assistant to the chief adviser for the health ministry, said those responsible for climate damage, both globally and locally, must be held accountable and contribute more funds to mitigation efforts. He urged the creation of a comprehensive intervention plan to reduce the health and economic impact of climate change.
IMPACTS ON HEALTH AND PRODUCTIVITY
The report highlights serious health and productivity consequences of rising temperatures. In summer, cases of diarrhoea and persistent cough nearly double compared to winter.
Nationally, 6 percent of surveyed individuals reported having persistent cough in summer, compared with 3.3 percent in winter. The elderly reported the highest prevalence of persistent cough, followed by those aged 50-65.
Women are disproportionately affected, with higher rates of heat exhaustion and heat stroke.
Mental health effects are also pronounced. Depression and anxiety rise during hotter months, with depression increasing progressively with age and anxiety peaking among those aged 50-65.
These health effects translate into significant productivity losses, which are far higher in the hotter months.
"Our analysis shows measurable links between exposure to heat and poorer health outcomes, alongside substantial productivity losses. Like many other countries, Bangladesh faces real risks of lost human capital and productivity," said Iffat Mahmud, senior operations officer at the World Bank and co-author of the report.
The World Bank has called for urgent, coordinated action to protect people, livelihoods, and the economy from escalating heat risks. The report urges stronger national preparedness through a multisectoral approach to heatwave management, upgrades to health systems to treat heat-related illness, and the expansion of urban green spaces.
It also stresses the need for better weather and health data to guide policy and for international public and private financing to help Bangladesh confront the growing impacts of global warming.