There is an emerging need for heat-resilient city systems - Indian local authorities are considering how to achieve this, report Shwetha Kutty, Mrunmayee Velukar and Priyesh Salunke of TARU.

Global warming and urbanisation have had severe impacts on local temperatures and changes in land use, causing Urban Heat islands, which is a well-known but unintended consequence of rapid urbanisation.

The Urban Heat island effect is exacerbated by paved surfaces and the lack of tree cover in cities - contributing to higher daytime temperatures, reduced night-time cooling, and higher air-pollution levels. These factors further lead to an increase in heat-related deaths and heat-related illnesses (EPA, 2020). Health impacts due to heat stresses have been on the rise since the last decade, which can be attributed to climate change.

The International Labour Organization reports that by 2030, the equivalent of more than 2% of total working hours worldwide is projected to be lost every year, either because it is too hot to work or because workers have to work at a slower pace.

Various studies and models have also projected that global surface temperature will be more than 0.5°C (0.9°F) warmer by the end of 2020 warmer than the 1986-2005 average. Temperature records from various studies show a significant increase in temperature from the start of the 20th century, with the year 2019 ranking among the top three warmest years on record. Considering these factors and the projected increase in temperatures globally, there is an emerging need to address urban heat.

Evidence from India

According to the Global Climate Risk Index, India ranks as the fifth-most vulnerable country in terms of extreme weather events and climate change. A Global Review 2017, states that if the current trend of warming continues, people directly exposed for six hours or more may not survive due to increased levels of heat and humidity by the end of the century (NDRC, 2019).

Around 6,187 deaths have occurred in India due to heat stress between 2011-2018, causing great concern for authorities and citizens alike. Furthermore, global pandemics such as Covid-19 has put our health and governance systems under great stress, such that emergency response to heat-related illnesses may not be prioritised. Such unprecedented events have further led to the realisation that there is an urgent need to improve our current health systems to be risk resilient.

As a rapidly developing nation, the economic impact of heat stress events in India have serious consequences on the economically productive population. Reports suggest that India is projected to lose 5.8% of working hours in 2030, a productivity loss equivalent to 34 million full-time jobs, due to global warming, particularly impacting agriculture and construction sectors (ILO, 2019). Evidence also suggests that India’s average temperature has risen by 0.7°C (33.2°F) between 1901 and 2018 and will rise by 4.4°C (39.9°F) by 2100 (K Raghavan et al, 2020). This can have direct and indirect effects on public health, as all-cause mortality has been observed to increase by 11% when mean daily temperature crosses 40°C (Desai, et al., 2015).

In 2010 Ahmedabad suffered a heatwave recording a temperature of 47°C, subsequently health officials recorded an excess of 800 deaths from the average mortality during the heatwave between 20-27 May 2010. This is also evidenced by an Ahmedabad specific study which concluded that there was a 43.1% increase in all-cause mortality during heat waves (Azhar, et al., 2014). In addition to this, 1344 excess deaths were recorded in the month of May 2010 in Ahmedabad. (Azhar, et al., 2014) To counter the effects of heat stress events, concerned authorities at the centre, state and local level are working towards better preparedness to build heat resilience and protect communities.

National level response  

At the national level, the Indian Meteorological Department (IMD) and National Disaster Management Authority (NDMA) work together to respond to anticipated heatwaves. The updated guidelines of NDMA identified that 23 heat-prone states should strengthen preparedness, mitigation and management of heatwaves. Heat Action Plans (HAP) focus on building climate resilience to extreme heat events through public awareness and community outreach; early warning system and interagency coordination; capacity building among health care professionals; and reducing heat exposure and prompting adaptive measures. (Jaiswal, Knowlton, & Limaye, n.d.). The Heat Action Plans prepared by cities demonstrate the regional approaches to early warning systems and heat preparedness plans for extreme heat in India.

Indian city-level response – Policies and actions

Cities and regions across India are taking concrete action to better prepare and protect local communities from deadly heat, as climate change increases temperature, frequency and severity of heat waves. The heatwave of 2010 in north-western Gujarat prompted the city of Ahmedabad to implement South Asia’s first heat wave early warning system and preparedness plan offering an innovative approach to address rising temperatures. In the subsequent years, several cities have followed suit and prepared respective Heat Action Plans (HAP). More than 11 states encompassing 30 cities in India have already taken action for implementing HAPs as of 2018.

The primary purpose of a Heat Action Plan (HAP) is to increase preparedness of all stakeholders and mobilize communities to help protect themselves against avoidable health problems during spells of very hot weather. Such disaster events usually have two types of responses, through mitigation (reduction of source causes) and adaptation (establishing mechanisms to cope with events). Inarguably, adaptation measures such as Heat Action Plans are vital in successfully handling and managing heat wave conditions. However, in addition to HAPs, there is a larger need to reflect upon how Indian cities can mitigate heat stress and strengthen heat-related resilience.

Cities in India must work towards adopting short- and long-term measures for adaptation as well as mitigation of heat stress events. Authorities can initiate significant planning measures to design cities in a climate resilient manner. Urban planning elements such as green roofs, natural cooling techniques, spray parks for cooling and creation of urban forests are examples of city infrastructure that are designed to ensure long term sustainability of the city environment. To support this effort, city authorities can initiate operational and policy driven changes to implement the prioritised goals.

These measures can be put into action through potential interventions such as technological solutions, institutional reforms, and capacity building or awareness programs. It would also be beneficial to prepare guidance documents that can identify scalable solutions at the neighbourhood, city and regional levels. Such documents are helpful in providing targeted solutions that can guide relevant stakeholders in implementing solutions. Such a coordinated, city-specific solution has been developed for Surat city by Taru Leading Edge, with the support of CDKN.

City Heat Resilience Toolkit – A city-specific solution to Surat’s heat distress

The ‘City Heat Resilience Toolkit’ is a comprehensive document for understanding the root causes, ways to prioritise them as well as recommending relevant solutions to the cities in India. The document considers the secondary literature and primary learnings from the coastal city of Surat for the purpose of providing an end-to-end framework to prevent heat stress not only at personal health level but also at the city level.  The three steps provided in the tool kit to identify contextual challenges are as follows:

Step 1: How to identify the root causes of heat stress in the city – Evidence generation

Step 2: Identifying the solution – the type, scale and areas of intervention

Step 3: Prioritisation of the solutions

The toolkit provides a framework for prioritising these issues and provides recommendations with which local governments can put these methods into practice, including:

1. Technological/ infrastructure solution;
2. Mandates/ policy recommendation, (i.e., building codes)
3. Incentives/ financing solutions, (i.e., fee rebates or grant programs) and
4. Community participation approaches

Thus, the toolkit facilitates the identification of causes of extreme heat in Indian cities and identifies various ways to prioritise the causes by providing relevant solutions.

For further reading and reference, the toolkit can be viewed and downloaded here.

Further reading

Azhar, G. S., M. D., Nori-Sarma, A., Rajiva, A., Dutta, P., Jaiswal, A., . . . (2014), A. H. (2014). Heat-related mortality in India: excess all-cause mortality associated with the 2010 Ahmedabad heat wave. PloS one, 9(3), e91831.

Desai, V. K., Wagle, S., Rathi, S. K., Patel, U., Desaai, H., & Khatri, K. (2015). Effect of ambient heat on all-cause mortality in the coastal city of Surat, India.

EPA, E. P. (2020). Heat Island Impacts.

ILO, O. I. (2019). Working on a Warmer Planet - The Impact of Heat Stress on Labour Productivity and Decent Work.

K Raghavan et al, M. o. (2020). Assessment of Climate Change over the Indian Region.

Lindsey, R., & Dahlman, L. (2020). Climate Change: Global Temperature.

Tripathi, B. (2020, June 16). India Underreports Heatwave Deaths. Here’s Why This Must Change.

Image: top right, City of Surat, courtesy S Chatterji, flickr.com