Climate change’s hidden toll: The impact on global life expectancy

In a ground breaking study published in the open-access journal PLOS Climate, researcher Amit Roy from Shahjalal University of Science and Technology and The New School for Social Research in the US highlights the direct link between climate change and human life expectancy. The study, conducted from 1940 to 2020 across 191 countries, sheds light on the hidden costs of climate change and introduces a novel composite climate change index.

Traditionally, the visible impacts of climate change, such as floods and heatwaves, are well documented, but understanding its direct correlation with life expectancy has been challenging. Roy's study employs temperature, rainfall, and life expectancy data, controlling for economic differences between countries using GDP per capita.

The findings reveal a stark reality: a global temperature increase of 1°C is linked to an average decrease in human life expectancy of approximately 0.44 years, equivalent to about 5 months and 1 week. Even more striking is the composite climate change index, which, with a 10-point increase, is estimated to decrease the average life expectancy by 6 months. Women and people in developing countries are the ones who feel this impact the most.

The study emphasises that the threat of climate change is not merely environmental but poses a direct risk to global well-being, underscoring the urgency of addressing it as a public health crisis. The composite index, a first-of-its-kind metric, aims to standardise the global conversation on climate change, making it accessible to the non-scientific public and fostering collaboration among nations.

Dr Roy stresses the need for immediate action, focusing on mitigating greenhouse gas emissions and adapting to the changing environment. The study serves as a call to recognise climate change as a global health emergency, emphasising that efforts to reduce emissions and proactive initiatives are vital to protecting life expectancy and the health of populations worldwide.

Looking ahead, Dr Roy suggests localised studies on specific severe weather events, like wildfires and floods, to complement the broader approach. These events, not fully captured by temperature and rainfall analysis alone, necessitate targeted strategies for regions facing unique climate challenges.

The study's overarching message is clear: the impact of climate change extends beyond environmental concerns to directly affect the longevity and well-being of billions. Urgent and collaborative efforts on a global scale are imperative to address this multifaceted crisis, safeguarding the future for generations to come.