Bangladesh is likely to experience a change in several key measures of climate in the next 15-35 years, according to the World Bank’s 2024 Bangladesh Climate Risk Profile.
World Bank projections have Bangladesh’s average daily temperature to rise by 0.41°C by 2020-2039 and 0.89°C by 2040-2059, while temperature rose 0.16°C per decade between 1971 and 2020, or around 0.8°C in those 50 years.
World Bank projections also expect that by the mid-21st century, the number of days per year in which Bangladesh’s Heat Index (the temperature the body feels, accounting for humidity) exceeds 35°C will roughly double to 133 days, and the number of nights with a minimum temperature above 26°C will increase by almost two months to 133 nights. That is roughly equivalent to four and a half months, or almost 40% of the year.
Southern coastal divisions are expected to experience the greatest increase in high Heat Index days during pre-monsoon spring months, whereas the northern and eastern floodplains are expected to undergo increases during summer months.
The World Bank’s previous Climate Risk Profile of Bangladesh, published in 2021, noted that increasing periods of high heat are “a major threat to human health and living standards in Bangladesh”. Though it may seem like a small number, a shift of 0.89°C could pose significant threats to the welfare of millions of Bangladeshis.
With respect to rainfall, this year’s World Bank projections suggest that northern regions will experience an increase in annual precipitation by 2040-2059, especially during summer monsoon months. Southern divisions are expected to experience an annual decrease in precipitation between 2020-2039, especially during pre-monsoon spring months; and the central region, Dhaka, will experience an increase in overall rainfall, though there is no seasonal shift.
The highest average 5-day precipitation is also expected to rise by 25mm to 326mm by 2050. Northern divisions will see the greatest of these changes, particularly during the summer monsoon months.
Changes in temperature are also expected to have an effect on naturally occurring climate-related hazards.
Increases in climate variability can exacerbate Bangladesh’s seismic risk (the potential impact of earthquakes), particularly in eastern divisions and densely populated urban areas such as Dhaka.
Sea level rise will threaten Bangladesh’s deltaic coastal zones, causing a retreat in the coastline by the end of the century, and flooding along Bangladesh’s river systems and droughts in northwest divisions will likely persist.
This year's profile notes that “more than 90 million Bangladeshis (56% of the population) are estimated to live in ‘high climate exposure areas’ affected by multiple hazards”.
The World Bank’s previous Climate Risk Profile of Bangladesh, published in 2021, said that without changes, the number of people exposed to extreme river flooding is expected to grow by 6-12 million people by the 2040s, and those facing coastal flooding could grow by 2-7 million by the 2070s.
The previous Climate Risk Profile also noted that inequality will likely increase as “global modeling and local evidence all suggest that poor and marginalized groups, and women are likely to suffer disproportionately in a changing climate.”
These projections and their implications help to put the events of 2024 into context. This year, a total of 18.4 million people in 28 districts have been affected by Cyclone Remal, which struck Bangladesh in late May, and various flooding events across the country over the summer.
Given the projections discussed here, it seems that such events and their consequences are likely to persist and worsen in the coming years.
