If the global temperature rises from the current 1.2°C to 2 °C, the recurrence of extreme heat incidents is more probable
Climate change is significantly impacting Bangladesh, making it one of the most vulnerable countries to climate devastation. Despite contributing minimally to global emissions, Bangladesh faces severe climate risks, including rising sea levels, floods, and intensifying cyclones.
According to a recent report by the World Weather Attribution (WWA), heatwaves in Bangladesh and other South Asian countries have become 45 times more likely due to climate change. The report states that if the global temperature rises from the current 1.2°C to 2°C, the recurrence of extreme heat incidents will become even more probable.
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This grim projection took on visceral form in 2024, which has emerged as Bangladesh’s hottest year on record so far. All districts averaged temperatures between 40°-42°C through April, putting immense strain on the nation’s population and biodiversity. Billions across Asia endured extreme temperatures exceeding 40°C that made decidedly hotter and more likely by human influences on the climate system.
Analysis of Historical Weather Data
The scientists analyzed historical weather data for a region including India, Bangladesh, Myanmar, Laos, Vietnam, Thailand, and Cambodia. They found that in South Asia, a strong climate change signal was observed in the April mean temperature this year, with extreme temperatures now about 45 times more likely and 0.85°C hotter compared to pre-industrial levels.
Tragically, these extreme conditions proved deadly. At least 28 deaths were reported in Bangladesh, 5 in India, and 3 among displaced Palestinians – likely just the tip of the iceberg due to underreporting issues. Crop failures, livestock losses, water shortages, fish die-offs, school closures, and even depressed voter turnout in India’s Kerala state all stemmed from the historic April heat. These escalating temperatures pose significant threats to public health, agriculture, and overall livelihoods in one of the world’s most climate-vulnerable nations.
Probability of Extreme Heatwaves
In the larger South Asia region, an extremely warm April such as this one has a 3% probability of happening in a given year – or once every 30 years. The analysis also shows that similar heatwaves are twice as likely during El Niño conditions.
Climate Change Impact on Asian Heatwaves
A collaborative effort involving scientists from Lebanon, Sweden, Malaysia, the Netherlands, the United States, and the United Kingdom was undertaken to evaluate the extent to which human-induced climate change impacted the likelihood and severity of extreme heat events in three distinct Asian regions.
These regions include:
- West Asia, encompassing Syria, Lebanon, Israel, Palestine, and Jordan.
- The Philippines in East Asia.
- South and Southeast Asia, covering India, Bangladesh, Myanmar, Lao PDR, Vietnam, Thailand, and Cambodia.
Employing established peer-reviewed methodologies, the scientists analyzed to assess the influence of human-induced climate change on the probability and intensity of a 3-day April heatwave in West Asia and a 15-day April heatwave in the Philippines. Figure 1 illustrates these two regions, delineated in blue, while Figure 2 depicts the South Asia region. In the case of the latter, the analysis primarily relied on observed weather data rather than climate models, given the significant overlap with previous study areas.
The observational data for the entire month of April affirmed that the impact of climate change is likely comparable in magnitude to the heatwaves examined in 2022 and 2023. Consequently, the results of a comprehensive attribution analysis would not deviate significantly from these findings.
Bangladesh Experiences Increasing Heatwaves
Bangladesh has been facing increasing heat waves during the summer months in recent years. The ongoing year has been the hottest yet, with average temperatures ranging from 40° to 42° Celsius recorded in all districts.
Trends of Heatwaves in Bangladesh
Heat Wave in Bangladesh (2023)
In 2023, Bangladesh was engulfed by an extraordinary heat wave, unleashing unprecedented temperatures across the nation. From April to June, record-breaking highs scorched various regions, surpassing 40°C in some areas. The peak of this severe heat wave struck in early June, with meteorological stations documenting highs of 41°C, a pinnacle not seen in the past sixty years.
These temperatures soared well above the country’s typical monthly maximum of 30°C, and April’s average maximum of 33°C, marking a stark departure from the usual climate patterns.
Based on data collected by the BMD, Dhaka experienced 18 days of heatwave between April 13th and 14th in 1999, followed by 13 days in May of 2004. Similarly, Jashore saw 18, 19, and 20 days of heatwave in 2014, 2016, and 2017 respectively.
The BMD further reported 13, 10, 17, and 13 days of heatwave in Rajshahi during 2014, 2016, 2019, and 2022 respectively, while Chudanga experienced 19 and 23 days of heatwave in 2014 and 2019 respectively.
Mallik attributed the rise in heatwaves to a decrease in thunderstorm activity in the country. He noted that only one thunderstorm occurred in April of this year, whereas the Met Office recorded four in 2021, nine in 2022, and seven in 2023. Mallik emphasized that thunderstorms play a crucial role in mitigating hot weather, and their reduced frequency has contributed to the increase in heatwaves.
What to do to prevent heat stroke
Undeniably, human-induced climate change plays a significant role in the heatwave. It is an established fact that our cities, particularly Dhaka, suffer from poor planning. Structures are constructed on any available plot of land without consideration for their impact on the surrounding environment. Clusters of tall buildings obstruct wind flow and trap heat, while the extensive use of air conditioners contributes to higher temperatures.
Conclusion
The report highlights the significant impact of climate change on the frequency and intensity of heat waves in Bangladesh and the broader South Asia region. Despite its minimal contribution to global emissions, Bangladesh remains one of the most vulnerable countries to the devastating effects of climate change.
