Climate change is severely damaging human health around the world and will continue to worsen as temperatures rise, according to health and climate researchers.
So far, global warming has led to an increase in health-threatening high temperatures and heat-related deaths, more extreme weather disrupting food and water supplies, the spread of disease, lost labour hours and added pressure on healthcare systems.
These destructive effects will become greater and impact more people if global society does not curb its emissions, which are still rising and have the Earth on course to warm by 2.7C above pre-industrial levels by 2100 – more than double the rise as of 2023.
Put together by 114 experts from 52 institutions including UN agencies, the World Health Organisation and the World Meteorological Organisation, the eighth Lancet Countdown report provides the latest information on how climate change is affecting human health.
UN secretary-general Antonio Guterres, who was not involved in the report, said in response: “Climate breakdown has begun, and humanity is staring down the barrel of an intolerable future.
“There is no excuse for our collective inertia. Only powerful and immediate action will limit global temperature rise to 1.5C and avert the very worst of climate change.”
The researchers, led by University College London, said governments and banks are continuing to incentivise fossil fuel expansion through hundreds of billions of dollars of subsidies and investments, while the world’s 20 largest fossil fuel companies have increased production since last year.
Their new “health stocktake” shows, by looking at the most recent 10-year global average of 1.14C warming, heat-related deaths among the over 65s have increased by 85% over the last decade compared to 1991-2000.
Accounting only for a growing population would give an increase of 38%, while nearly two-thirds of the 86 days of health-threatening high temperatures between 2018-2022 were made twice as likely because of climate change, the researchers said.
They also found that increasingly frequent heatwaves and droughts were responsible for 127 million more people experiencing moderate to severe food insecurity in 122 countries in 2021 than in a typical year between 1981-2010.
Warmer seas have also increased the spread of Vibrio bacteria, which can infect people through uncooked seafood or open wounds in seawater and cause diarrhoea, sepsis and sometimes death.
It has spread 329 kilometres every year since 1982 – 142 kilometres in Europe – and now puts 1.4 billion people at risk.
The researchers found 27%, or 141 out of 525 cities they surveyed, reported concerns about their health systems being overwhelmed by impacts from climate change.
They also estimate that extreme weather cost 264 billion dollars (£214 billion) of economic losses in 2022, a 23% rise from 2010-2014.
Heat exposure caused 490 billion labour hours to be lost globally last year, an increase of 42% between 1991-2000, with losses felt more keenly in low and middle-income countries.
Dr Marina Romanello, executive director of the Lancet Countdown at University College London, said: “With 1,337 tonnes of carbon dioxide still emitted every second, we aren’t reducing emissions anywhere near fast enough to keep climate hazards within the levels that our health systems can cope with.
“There is an enormous human cost to inaction, and we can’t afford this level of disengagement – we are paying in lives.
“Every moment we delay makes the path to a liveable future more difficult and adaptation increasingly costly and challenging.”
The #C3S's monthly climate bulletin is out now:
📈 October 2023 was the warmest October on record globally, with an average surface air temperature of 15.30°C;📈 the average sea surface temperature for October was the highest on record for October.
— Copernicus ECMWF (@CopernicusECMWF) November 8, 2023
If greenhouse gas emissions do not decline, annual heat-related deaths could increase by 370% in 30 years, the researchers estimate, with heat exposure cutting the amount of labour hours globally by 50%.
More frequent heatwaves could lead to around 525 million more people experiencing food insecurity by mid-century, which will increase the global risk of malnutrition.
Deadly infectious diseases are also likely to continue spreading, with dengue fever expanding its transmission potential by around 37% and the coastline suitable for Vibrio bacteria growing by around 20%.
Professor Paul Ekins, Lancet Countdown working group lead on economics and finance, said: “With the world on the brink of irreversible harm, the fact that governments and companies shamelessly continue to invest in oil and gas amounts to them ensuring that the Paris 1.5C target will not be achieved, putting the health of millions of people at risk.
“Both this investment in fossil fuels, and the subsidies that continue to be poured into fossil fuel production and consumption, must be urgently redirected to incentivise the expansion and affordability of clean renewable energy and to activities that improve public health and resilience.”