Heat-related deaths, food insecurity and the spread of infectious diseases caused by the climate crisis have reached record levels, according to a landmark report.
The Lancet Countdown’s ninth report on health and the climate breakdown reveals that people across the world face unprecedented threats to their health from the rapidly changing climate.
“This year’s stocktake of the imminent health threats of climate inaction reveals the most concerning findings yet,” warned Dr Marina Romanello, executive director of the Lancet Countdown at University College London.
“Once again, last year broke climate change records with extreme heatwaves, deadly weather events, and devastating wildfires affecting people around the world. No individual or economy on the planet is immune [to] the health threats of climate change.
“The relentless expansion of fossil fuels and record-breaking greenhouse gas emissions compounds these dangerous health impacts, and is threatening to reverse the limited progress made so far and put a healthy future further out of reach.”
The report finds that in 2023, extreme drought lasting at least one month affected 48% of the global land area, while people had to cope with an unprecedented 50 more days of health-threatening temperatures than would have been expected without the climate crisis. As a result, 151 million more people faced moderate or severe food insecurity, risking malnutrition and other harm to their health.
Heat related deaths among the over-65s rocketed by 167% in 2023, compared with the 1990s. Without the climate crisis, an ageing global population means such deaths would have increased, but only by 65%. High temperatures also led to a record 6% more hours of lost sleep in 2023 than the 1986–2005 average. Poor sleep has a profound negative effect on physical and mental health.
Hotter and drier weather saw greater numbers of sand and dust storms, which contributed to a 31% increase in the number of people exposed to dangerously high particulate matter concentrations, while life-threatening diseases such as dengue, malaria and West Nile virus continue to spread into new areas as a result of higher temperatures.
But despite this, “governments and companies continue to invest in fossil fuels, resulting in all-time high greenhouse gas emissions and staggering tree loss, reducing the survival chances of people all around the globe”, the authors found.
In 2023, global energy-related carbon dioxide emissions reached an all-time high, 1.1% above 2022, and the proportion of fossil fuels in the global energy system increased for the first time in a decade during 2021, reaching 80.3% of all energy.
Responding to the findings, Dr Tedros Adhanom Ghebreyesus, director general of the World Health Organization, said: “The climate crisis is a health crisis. As the planet heats up, the frequency and intensity of climate-related disasters increase, leaving no region untouched.”
The report makes it clear, he added, that “climate change is not a distant threat, but an immediate risk to health”.
António Guterres, the United Nations secretary general, said: “Record-high emissions are posing record-breaking threats to our health. We must cure the sickness of climate inaction – by slashing emissions, protecting people from climate extremes, and ending our fossil fuel addiction – to create a fairer, safer and healthier future for all.”
Temperate countries are also seeing the effects of the climate crisis. In 2013-2022, the UK’s overall mean increase in heat-related deaths was estimated at nine deaths per 100,000 inhabitants, while there were 8.5 million potential working hours lost due to heat exposure in 2023.
Dr Lea Berrang Ford, head of the Centre for Climate and Health Security at the UK Health Security Agency, which published its own report on the health impacts of global heating on the UK, said: “Climate change is not solely a future health threat. Health impacts are already being felt domestically and globally, and these risks will accelerate.
“There are significant opportunities for win-win solutions that can combat climate change and improve health. The health decisions we make today will determine the severity and extent of climate impacts inherited by today’s youth and their children.”
Dr Josh Foster, lecturer in human environmental physiology at King’s College London, said the report’s “alarming” trends would “result in more frequent mass mortality events in older people as the devastating impacts of climate change are realised”.
