The cruellest month begins next week, and it’s time to brace for another summer of life-threatening heat. Earlier in March, former WHO chief scientist Soumya Swaminathan said India is probably undercounting heat-related deaths, and spoke of the need for better tracking and policy interventions based on reliable data.
Last year, the nonprofit HeatWatch reported 733 deaths and over 40,000 heat-stroke cases from 17 states, while the Union health ministry reported about half as many deaths. Governments like to downplay bad news, but uneven data collection standards are also at work here. The huge variation reminds us of how starvation deaths used to be reported decades ago, when extreme poverty was commonplace.
The eventual cause of most deaths is heart failure, but it can be brought on by a wide variety of factors; it was very easy for malnutrition and starvation deaths to be attributed to heart failure. Cultural ignorance also rang false alarms about starvation. Newspapers reported sensationally that tribals and poor communities in underdeveloped areas were living on roots and leaves. But these were sometimes traditional foods whose consumption has receded in the cities.
Geography matters, too―amaranth greens are commonly used as food in the east, but not regarded as food elsewhere. Similar confusions are now being seen in reporting the effects of extreme heat.
Traditionally, public health monitoring has focused on heatwaves (the 2024 count was the highest in 14 years) and heatstroke. The condition is associated with persistent heat in a dehydrating climate, and low-tech and cheap interventions like ‘chik’ drapes and coolers were useful antidotes. Now, the picture has changed. Irrigation, intensive cultivation, plantations, and afforestation have increased humidity in traditionally dry zones, rendering cooling through evaporation difficult. In thickly populated areas, the effect is palpable―as time passes, the heatmaps of cities are turning red.
The Shared Socioeconomic Pathways (SSP) defined by the Intergovernmental Panel on Climate Change in 2021 suggests how the world could heat up. SSP1 is the most optimistic scenario and assumes that governments will promote sustainability. In SSP5, the world continues to rely on fossil fuels t, but invests progressively in health, education, and institutions, amplifies globalisation, and can contain global problems like pollution. The middle-of-the-road SSP2 is business as usual uneven growth, slow but steady progress towards climate goals, more intelligent use of energy, and a taper in population growth.
SSP2 was taken to be the most credible storyline, but now, the world seems to be turning towards SSP3 and SSP4, which feature growing inequality among people, nations, and regions, and competitive nationalism, which valorises national and regional issues, and fails to unite to address global challenges like the environment. In some areas, this disunity has been visible. The Arctic, where warming seas present a serious problem, remains the domain of eight stakeholder nations with territory in the region.
But the Arctic is called the weather factory of the world, in recognition of its role in determining global weather patterns. But due to geographical distance, countries in South Asia, which are feeling the effects of climate change very keenly, have almost no say in how Arctic ecology is conserved. By fragmentation, the world order, nationalism, and regionalism would leave the least capable and most vulnerable nations to face their problems including those created far away on their own. This is unrealistic because public health problems do not respect borders.
In the past, bacterial diseases like the plague have swept across borders, even across continents and oceans, and viral diseases like Covid are still doing it, even as TB is making a comeback. However, communicable diseases are no longer the world’s biggest killers. Lifestyle disorders like diabetes and cardiovascular and neurological conditions have assumed the mantle. How the weather affects their prognosis remains unknown, but the effect will be felt everywhere.
The focus is currently on counting excess deaths and hospitalisations, because it will take years yet for the effects of weather to be correlated with morbidity due to lifestyles.
Age-related disorders like Alzheimer’s and dementia, whose incidence is increasing, are of interest in this context. A study in progress among slash-and-burn cultivators and hunter-gatherers in the Amazon forest of Bolivia confirms something we sense instinctively―‘primitive’ cultures suffer from a lot of communicable diseases but almost no lifestyle disorders, including those associated with ageing. There is growing evidence in support of the folk belief that lifestyle disorders are associated with modern living. If there’s any truth in that, they may be exacerbated by anthropogenic factors like extreme heat.
If evolving global politics favours disunity among nations, as it seems to be doing, issues that require concerted action and do not respect borders, like the environment, will be among the first casualties. And the developing nations will find themselves saddled with the burden of poorly understood diseases, and of conditions like heat stress, on their own.
Pratik Kanjilal | Fellow, Henry J Leir Institute of Migration and Human Security, Fletcher School, Tufts University
(Views are personal)
(Tweets @pratik_k)