Assessing the Disease Burden considering Climate Change Scenarios in future time-periods: State-Level Health Assessment for India | 2025 - 2050

Climate change is no longer a distant prospect but a lived reality, disrupting natural systems and threatening human well-being across the globe. India stands at the forefront of the crisis, where Intergovernmental Panel on Climate Change (IPCC) 6th assessment report has marked it as a climate hotspot due to its wide geographic and socio-economic disparity. It is increasingly shaping patterns of disease, mortality, and strain on already overburdened health system in India. Rising temperatures, changing rainfall patterns, and deteriorating air quality are influencing the spread and intensity of climate-sensitive diseases, including heat-related illnesses, vector-borne diseases, water-borne infections, and air pollution-related conditions. While these risks are widely acknowledged, the vulnerability is not experienced equally and is shaped by gender, caste, age, geographic location, and access to healthcare. Thus, it remains a critical gap in state-level evidence that can inform targeted public health planning and resource allocation.

In this context, TERI undertook a comprehensive assessment to examine the current and projected burden of climate-sensitive diseases across Indian states, with a focus on the period 2025–2050. The study integrates downscaled climate projections, population trends, and historical health data to generate insights on anticipated disease burden under different climate scenarios. This analysis identifies both spatial and temporal patterns of vulnerability across states. The key health outcomes linked to climate variability analysed includes heatwave-attributable mortality and productivity loss, dengue, malaria, and cholera incidence, and air pollution-related diseases mortality, Disability-adjusted life years (DALYs), and Years of lost life (YLL).

A central component of the work involves modelling future disease burdens under two emission pathways, capturing both moderate and high climate change trajectories (e.g., RCP4.5, RCP8.5). The findings indicate a consistent increase in health risks across multiple geographies, with certain states emerging as high-burden hotspots due to the combined effects of environmental exposure, population growth, and existing health system constraints. In addition to epidemiological projections, the study evaluates the economic implications of climate-sensitive diseases. By estimating costs associated with mortality and morbidity, it provides a clearer picture of the potential strain on households and health systems. This economic lens strengthens the case for early investment in preventive and adaptive strategies.

The key conclusions emerging from the assessment were –

• Heatwaves emerge as a major health threat with significant increase in heatwave-attributed mortality and productivity losses.
• PM5 attributed mortality & morbidity show strong growth trends, particularly in the Indo-Gangetic plain regions.
• New hotspots were identified for water- and vector-borne disease highlighting a shift in disease ecology.
• Air pollution was also noted as a major contributor of future economic health burden.
• Climate impacts were highly uneven across states. While northern states faces severe heat and air-pollution risks, coastal and eastern states experienced higher risks of water- & vector-borne diseases.

Together, these results provide a comprehensive picture of the evolving health risks posed by climate change, highlighting vulnerability hotspots, temporal trends, and the magnitude of projected economic impacts. It supports the development of state-level adaptation strategies by identifying priority risks, vulnerable populations, and potential intervention points. By linking climate science with public health data, the work enables more informed decision-making and reinforces the need to integrate health considerations into broader climate policy frameworks. The study thus contributes to strengthening the evidence base for building climate-resilient health systems in India.