Heat Health in Bangladesh: Defining and Predicting Heat Waves Across Timescales

It is now well established that extreme heat poses a serious health risk, causing many excess deaths each year. However, near the tropics, where temperatures exhibit less variability and hot weather is the norm, the perceived risk is often low. Other natural hazards, or broader goals of economic and social development may be considered higher priorities for countries with limited resources. However, the blistering temperatures reached in South Asia in recent years have contributed to a growing awareness that heat waves do pose a serious health risk in this part of the world^1,2 At the first Climate Services Forum for Health, held in Sri Lanka in 2016, representatives from South Asian countries gathered to discuss this issue and identified heat wave early warning systems as an important goal for the region.³

Reliable forecasts are an essential building block of an effective early warning system. These are needed at a sufficient lead time to enable preparatory action to be taken in advance of a heat wave. Yet good forecasts are not possible without a solid understanding of the occurrence and behavior of heat waves, and so far there has been little research in this area for South Asia. This study focuses on Bangladesh, one of the most motivated countries in the region in this regard.  The presentation will examine the physical characteristics of heat waves in Bangladesh, exploring the roles of synoptic dynamics, the land surface and variability in the global oceans as drivers of these events. Results suggests that opportunities exist for extended range prediction of heat waves in Bangladesh, offering the potential to provide more advance warning and increasing the capacity to prepare. Outstanding obstacles to the implementation of an effective early warning system will also be discussed, including strategies for the development and dissemination of clearly communicated heat forecast information to decision makers in the health sector.

1.       Azhar, G. S. et al. Heat-related mortality in India: Excess all-cause mortality associated with the 2010 Ahmedabad heat wave. PLoS One 9, (2014).

2.       Wu, H. Mercury rising: India records its highest temperature ever. CNN (2016).

3.       WHO-WMO Joint Office for Climate and Health. Improving health preparedness for extreme heat events in South Asia. in Climate Services Forum for Health (CSF-Health) (2016).