Traditionally, climate change as an issue has always been discussed by climate scientists and advocates. But recently, a commission convened by the World Health Organization (WHO) has recommended that the climate crisis must be declared a public health emergency of international concern. We have entered an era where the climate crisis is no longer only an environmental or sustainability issue. It is a growing public health and economic risk with immediate and long-term consequences. Research shows that globally, the climate crisis could contribute to 14.5 million additional deaths and over $1.1 trillion in healthcare costs by 2050.
The acute effects of the climate crisis on health are visible in the form of heat waves causing dehydration and heart stroke. But what is invisible is how the climate crisis and chronic diseases intersect. Non-communicable diseases account for nearly 63% of all deaths in India, with cardiovascular diseases alone contributing to 27% of mortality. On one hand, environmental stressors such as heat, pollution, and water insecurity increase the risk and severity of chronic illnesses. On the other hand, people already living with non-communicable diseases are more vulnerable to climate-related health shocks. For example, repeated dehydration and prolonged exposure to extreme temperatures can worsen cardiovascular disease and increase hospitalisations during heatwaves.
At the same time, air pollution and water stress increase inflammation, infection risk and metabolic stress, making conditions like diabetes, hypertension and cardiovascular disease harder to manage. Research also shows that temperature variability alone can increase chronic kidney disease (CKD) incidence by more than 7%. Additionally, long-term exposure to poor air quality has been linked to higher risks of heart disease, stroke and respiratory illness.
Outdoor workers in sectors such as agriculture, construction and transport are particularly vulnerable because of long hours spent in high-heat environments with limited access to cooling and hydration. For vulnerable populations with limited access to health care, the impact is even more severe. Heatwaves and extreme weather events can disrupt treatment continuity, delay diagnosis and reduce access to medicines and health care facilities, placing additional pressure on already stretched health systems.
The impact is also economic. The International Labour Organization estimates that heat stress alone could result in productivity losses equivalent to 80 million full-time jobs globally by 2030.
The response must operate at two levels: Managing current health impact and reducing climate risk
First, health systems must respond to what is already visible today. This means moving earlier in the care pathway by strengthening screening and early detection for conditions such as CKD, hypertension and cardiovascular disease, especially in climate-vulnerable regions. Primary healthcare workers must also be equipped to recognise climate-related risks including heat stress, dehydration and respiratory complications before they become medical emergencies.
Building community awareness is equally critical. Many people living with chronic diseases still do not recognise how heat exposure, dehydration and poor air quality can worsen existing conditions. Preventive health care, public awareness campaigns and improved access to local care can help reduce long-term disease burden and improve outcomes.
Second, the root cause must also be addressed by reducing climate risk itself. For corporates, this is no longer a sustainability discussion operating at the margins. Climate resilience must become part of how institutions and companies plan for the future. Climate risk is now directly linked to workforce productivity, supply chain resilience and health care costs. Reducing emissions, strengthening climate resilient infrastructure and investing in healthier workplaces will become increasingly important to long term business continuity. Investors and regulators are also placing greater focus on environmental performance and long-term resilience planning. Companies that fail to adapt risk both operational and reputational impact.
Addressing this challenge requires coordinated action across sectors. Governments, health care providers, industry and civil society must work together to design solutions that are locally relevant and scalable. The Ghana Heart Initiative, launched through a partnership between the Government of Ghana, the WHO, climate and health experts, GIZ and industry partners, offers one example of how collaboration can strengthen cardiovascular care for climate vulnerable populations. The initiative strengthened health care worker training, improved screening and referral systems at the primary care level. This led to the establishment of national guidelines for risk assessment and management of CVDs in Ghana.
Climate is already reshaping disease patterns and health outcomes across India. The response must be equally deliberate, addressing both the health impact visible today and the climate risks that will define our tomorrow.
(The views expressed are personal)
This article is authored by Shweta Rai, managing director, India and Country Division Head, South Asia, Bayer Pharmaceutical Division.
