Could Fossil Fuel Phase-Out Save Lives and Money?

Heat-related mortality has increased by 63% since the 1990s as a result of insufficient action to limit climate warming, The Lancet has revealed.

The reduction in labour capacity caused by heat exposure resulted in global potential income losses exceeding US$1tn.

The medical journal’s 2025 Report of the Lancet Countdown on Health and Climate Change, produced in collaboration with the World Health Organization, details the impacts of climate change and health. 

It points to a phase-out of fossil fuels as one of the biggest levers for change.

The report “paints a stark picture”, says Adam Elman, Director of Sustainability EMEA at Google, on LinkedIn. 

“Despite the clear and escalating crisis, we see worrying backsliding.

“However, the report highlights that progress is possible and yields immediate benefits!”

Rising temperatures and mortality rates

The research indicates that 16 of the 19 life-threatening heatwave days experienced annually by populations between 2020 and 2024 would not have happened without climate change.

Heat was associated with nearly 1% of all deaths recorded between 2012 and 2021, according to the findings.

This percentage rose to 1.73% in countries with low Human Development Index rankings, while very high HDI countries saw 0.53%.

Heat-related mortality stood at an average of 5.9 deaths per 100,000 people between 1990 and 1999.

By 2012 to 2021, this figure had climbed to 7.2 deaths per 100,000.

Rising temperatures are also affecting sleep patterns, with 2024 witnessing a 9% increase in sleep loss from baseline levels.

This represents the greatest percentage rise in lost sleep recorded over the past decade.

“This report once again provides strong evidence that the impact of climate change is being counted not just in degrees and carbon metric tonnes but in lives lost," says Dr Githinji Gitahi, Group CEO of AMREF Health Africa.

“The science reflects what communities across Africa experience daily – bearing the brunt of increasing heat-related deaths, rising infectious disease threats and growing food and water insecurity," he adds.

“Health is the human face of climate change.”

Extreme weather and displacement

Extreme weather events throughout 2024 resulted in at least 16,000 deaths and impacted a minimum of 166 million people, compounded by adaptation delays, according to the research.

These events are estimated to have displaced more than 800,000 individuals.

Research referenced in the findings identified that anthropogenic climate change heightened the intensity or likelihood of at least 26 of 2024's most severe extreme weather events.

More than 3,700 deaths can be attributed to these combined impacts.

A record 61% of the world's land area experienced extreme drought conditions in 2024, representing a 299% increase from 1950s averages.

Such conditions could threaten food and water security, sanitation systems and trigger subsequent economic losses.

Wildfires are becoming more likely due to hotter and drier conditions, with 2024 recording a peak of 154,000 deaths linked to wildfire smoke-derived small particulate matter air pollution.

Climatic conditions are also creating environments more conducive to the transmission of fatal infectious diseases, the research notes.

The socioeconomic impacts compound these direct health consequences, with potential income losses from heat reaching a record US$1.09tn in 2024 and weather-related extreme events causing losses surpassing US$304 bn.

“The climate crisis is a health crisis. Every fraction of a degree of warming costs lives and livelihoods,” says Dr Jeremy Farrar, Assistant Director-General for Health Promotion and Disease Prevention and Care at the World Health Organization.

“This report, produced with WHO as a strategic partner, makes clear that climate inaction is killing people now in all countries," Jeremy adds.

"However, climate action is also the greatest health opportunity of our time. Cleaner air, healthier diets, and resilient health systems can save millions of lives now and protect current and future generations.”

Priorities for policy and business

The Lancet’s report also outlines a few priorities for the protection of health amid global turmoil.

National governments, it says, can promote a safer future through creating supportive regulations and financial incentives applied to both the public and private sectors. 

These policies should help to enable affordable renewable energy, energy efficiency and a safe fossil fuel phase out, which the report describes as “essential” to keep climate risks within levels that countries can adapt to. 

For private sector organisations, the report recommends setting science-based targets, divesting from fossil fuels, transitioning towards renewable energy and developing collaborations to advance climate change action.

Professor Charlotte Watts, Executive Director, Solutions at Wellcome, says: “Progress is being held back by underfunding and wavering political will. This must change. 

“At COP30, governments have a chance to accelerate health-centred climate action. Addressing the sources of climate change and investing in climate change adaptation will save people’s lives, strengthen economies and cut emissions to secure a better future.” 

Elsewhere, Laura Clarke, CEO of ClientEarth, says: “We know what is needed to create a better future of clean air, healthy food and liveable cities. But too many governments and companies are turning away from that task, and even fuelling the climate crisis. 

“As attribution science, climate litigation and grassroots activism grow, accountability for climate impacts is no longer a question of if, but when.”