This year, India and Pakistan have recorded their warmest ever March and April. The pre-monsoon period in South Asia is usually marked with excessively high temperatures, especially in May but early heatwaves like this signal complex, compounding and cascading risks. Scientists believe that early heatwaves are consequent of persisting north-south low-pressure patterns that form over India during winters when a La Niña phenomenon occurs in the equatorial Pacific Ocean.
The Intergovernmental Panel on Climate Change (IPCC), in its Sixth Assessment Report, highlights that heatwaves and humid heat stress in South Asia are set to be more intense and frequent this century. Further, ESCAP estimates that the intersection of aridity with projected temperature rise will result in increasing areas of concern for heatwaves in South and Southwest Asia with occurrence of distinct hotspots. The present heatwaves in India and Pakistan are in these hotspots.
Heatwaves have multiple cascading social, ecological, and economic impacts in the immediate and long terms. South Asia, with its critical socio-economic vulnerability, witnesses deeper impacts. Heat-related mortality has been higher in areas with high population density, inequalities, limited access to health care, high pollution levels and fewer green spaces.
A recent study highlights that India is the most impacted country with largest heat exposure to country's labour productivity. It loses labour productivity of more than 100 billion hours per year while the global sum is 220 billion. The labour productivity losses in China, Bangladesh, Pakistan, Indonesia, Viet Nam, Thailand, and Philippines are relatively much less. With additional 1 to 2 degree warming; the labour productivity losses go up to 156 and 230 billion hours respectively in India (Figure 2). The International Labour Organisation (ILO) Report estimates that labour productivity losses associated with reductions in work rate due to heat exposure can be as high as ~280--311 billion $US per year. These are mostly attributed to losses in low- and middle-income countries including those in South Asia in sectors involving heavy manual labour, like agriculture and construction.
Heat Action Plan: To minimize the heatwave impacts, countries in Asia and the Pacific have put in place heat action plans to better understand and more effectively predict, prepare, and respond to extreme heat risks. For example, India and Pakistan have the heat-health early warning systems and action plans. The city of Ahmedabad in India was the first South Asian city to develop and implement a city-wide heat health adaptation in 2013 after experiencing a devastating heatwave in 2010. Since then, this successful approach has been implemented in 23 heatwave-prone states in India, protecting more than 130 cities and districts. Similarly, in the summer of 2015, a heatwave engulfed much of central and north-west India and eastern Pakistan resulting in thousands of fatalities. This led to development of Pakistan’s Heat Action Plan. In India too, Heat Action Plans have resulted in reducing heatwave related fatalities from 24,223 between 1992-2015 to 4 in 2020. However, the early onset of heatwaves in India this year poses new challenges with states like Maharashtra already having recorded 25 fatalities from heatstroke since March 2022.
A sub-regional action pathway: Success of a Heat Action Plan relies on precise warnings. Considering the transboundary nature of heatwaves, a regional/sub-regional Heat Action Plan that captures all regional/sub-regional specificities prove to be an effective tool. In this context, The Global Heat Health Information Network (GHHIN), a joint venture of the WHO and WMO, is an important initiative. The South Asia Heat Health Information Network (SAHHIN) works to share lessons and raise capacity across the South Asia. The South Asia Climate Outlook Forum (SASCOF) helps to prepare consensus based seasonal climate information on regional scale that provides a consistent basis for preparing national level outlooks. In April this year, SASCOF released a consensus Statement on the Seasonal Climate Outlook for the 2022 Southwest Monsoon Season (June – September). Translating the Seasonal Climate Outlook to impact forecasting, ESCAP added value to the Statement by identifying the hotspots of vulnerable population likely to be exposed to low precipitation and high temperature. This is an important contribution to initiate anticipatory action for managing heatwaves.
Hence, subregional initiatives such as SAHHIN and SASCOF are building blocks of a sub-reginal pathway. ESCAP’s Risk and Resilience Portal, an initiative of Asia-Pacific Disaster Resilience Network, is also an effort to strengthen such sub-regional pathways for adaptation to heatwaves and a help build a resilient future for all.