• New global projections in the 8th annual report of the Lancet Countdown on Health and Climate Change reveal the grave and mounting threat to the health of further delayed action on climate change, with the world likely to experience a 4.7-fold increase in heat-related deaths by mid-century.

• The report also highlights how climate inaction is costing lives and livelihoods today. In 2022, individuals were, on average, exposed to 86 days of health-threatening high temperatures, of which 60% were made at least twice as likely to occur because of human-caused climate change.

• Authors call out the “negligence” of governments, companies, and banks who continue investing in oil and gas as the challenges and costs of adaptation soar and the world approaches irreversible harm. They warn that without profound and swift mitigation to tackle the root causes of climate change, the health of humanity is at grave risk.

• The new regional section of the report highlights the different and unequal experiences of the health impacts of climate change, who is benefiting from climate change adaptation, and the health co-benefits of the clean energy transition so far. The authors outline the opportunity that a just energy transition offers to reduce health inequities and improve the health and well-being of all populations.

• Authors argue the stark findings must force urgent health-centered climate action to shift the global economy to a zero-carbon footing while delivering “transformative opportunities” to

improve the health of world populations through improved energy access and security, cleaner air, safer drinking water, healthier diets and lifestyles, and more liveable cities.

New data reveal the catastrophic threat to the health and survival of billions of people all over the world and successful adaptation efforts, from any further delays in action to limit temperature increase to 1.5°C above pre-industrial levels, according to the 2023 Report of The Lancet Countdown on Health and Climate Change: The imperative for a health-centred response in a world facing irreversible harms.

With the world currently on track for 2.7°C of heating by 2100 and energy-related emissions reaching a new record high in 2022, the lives of current and future generations hang in the balance.

“Our health stocktake reveals that the growing hazards of climate change are costing lives and livelihoods worldwide today. Projections of a two °C hotter world reveal a dangerous future and are a grim reminder that the pace and scale of mitigation efforts seen so far have been woefully inadequate to safeguard people’s health and safety”, says Dr Marina Romanello, Executive Director of the Lancet Countdown at University College London. “With 1,337 tonnes of carbon dioxide emitted every second, we aren’t reducing emissions anywhere near fast enough to keep climate hazards within the levels our health systems can cope with. Inaction has an enormous human cost, 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 8th Lancet Countdown report led by University College London represents the work of 114 leading experts from 52 research institutions and UN agencies worldwide, including the World Health.

Organization (WHO) and the World Meteorological Organisation (WMO) provide the most up-to-date assessment of health and climate change links. Published ahead of the 28th UN Conference of the Parties (COP), the report presents 47 indicators that include new and improved metrics that monitor household air pollution, financing of fossil fuels, and engagement from international organizations on the health co-benefits of climate mitigation.

“There is still room for hope,” says Dr. Romanello. “The health focus at COP28 is the opportunity of our lifetime to secure commitments and action. If climate negotiations drive an equitable and rapid phase-out of fossil fuels, accelerate mitigation, and support adaptation efforts for health, the ambitions of the Paris Agreement to limit global heating to 1.5 °C are still achievable, and a prosperous, healthy future lies within reach. Unless such progress materializes, the growing emphasis on health within climate change negotiations risks being just empty words, with each fraction of a degree of heating exacerbating the harms felt by billions of people alive today and the generations to come.”

Climate inaction is already costing lives and livelihoods

The failure to mitigate climate change seriously is self-evident, with health-related losses and damages soaring globally. In 2023, the world experienced the hottest global temperatures in over 100,000 years, and heat records were broken on every continent, exposing people worldwide to deadly harm.

Even at the current 10-year global average of 1.14°C of heating, people experienced 86 days of health-threatening high temperatures in 2018-2022, over 60% of which were made more than twice as likely to occur because of artificial climate change. Heat-related deaths in people over 65 increased by 85% in 2013-2022 compared to 1991-2000, substantially above the 38% increase expected had temperatures not changed (i.e., accounting only for changing demographics).

The increasing destructiveness of extreme weather events jeopardizes water security and food production, putting millions at risk of malnutrition. More frequent heatwaves and droughts were responsible for 127 million more people experiencing moderate to severe food insecurity in 122 countries in 2021 than annually between 1981 and 2010.

Similarly, changing weather patterns are accelerating the spread of life-threatening infectious diseases. For example, warmer seas have increased the area of the world’s coastline suitable for the spread of Vibrio bacteria that can cause illness and death in humans by 329km every year since 1982, putting a record 1.4 billion people at risk of diarrhoeal disease, severe wound infections, and sepsis [3]. The threat is exceptionally high in Europe, where Vibrio-suitable coastal waters have increased by 142km yearly.

Healthcare systems are the first line of defense for protecting people from the growing health harms of the changing climate. But even the current 1.14°C of heating is putting severe pressure on health services, with 27% (141/525) of surveyed cities reporting concerns over their health systems being overwhelmed by the impacts of climate change.

Strikingly, the total value of economic losses resulting from extreme weather events was estimated at US$264 billion in 2022, 23% higher than in 2010-2014. Heat exposure also led to 490 billion potential labor hours lost globally in 2022 (a nearly 42% increase from 1991-2000), with income losses accounting for a much higher proportion of GDP in low- (6.1%) and middle-income countries (3.8%). These losses increasingly harm livelihoods, restricting the capacity to cope and recover from the impacts of climate change.

“We’re facing a crisis on top of a crisis,” warns Dr. Georgiana Gordon-Strachan, Director of the Lancet Countdown Regional Centre for Small Island Developing States. “People living in poorer countries, who are often least responsible for greenhouse gas emissions, are bearing the brunt of the health impacts but are least able to access funding and technical capacity to adapt to the deadly storms, rising seas, and

crop-withering droughts worsened by global heating. Despite this, rich nations have broken their

long-standing pledge to deliver the comparatively modest sum of US$100 billion a year to help vulnerable countries cope with climate change, jeopardizing a fair, equitable transition to a healthy future.”

New projections expose health imperative for urgent mitigation.

For the first time, this year’s report provides a disturbing glimpse of what could lie ahead in a heating world. New projections, developed with the support of the Climate Vulnerability Forum (CVF), outline the rapidly growing risks to population health if the 1.5°C target is missed, with every health hazard monitored by The Lancet Countdown predicted to worsen if temperatures rise to 2°C by the end of the century.

Under this scenario, yearly heat-related deaths are projected to increase by 370% by mid-century, with heat exposure expected to increase the hours of potential labor lost globally by 50%. More frequent heatwaves could lead to around 525 million more people experiencing moderate to severe food insecurity by 2041-2060, exacerbating the global risk of malnutrition [4].

Life-threatening infectious diseases are also projected to spread further by mid-century, with the length of coastline suitable for Vibrio bacteria expanding by 17%–25% and leading to 23–39% more cases, and the transmission potential for dengue increasing by 36%–37%—contributing to its rapid global expansion.

“In the face of such dire projections, adaptation alone cannot keep up with the impacts of climate change, and the costs are rapidly becoming unsurmountable,” says Professor Stella Hartinger, Director of the Lancet Countdown Regional Centre for Latin America. “We must go beyond treating the health symptoms of climate change to focus on primary prevention. The root causes of climate change must be tackled through rapidly accelerating mitigation across all sectors to ensure the magnitude of health hazards does not breach the capacity of health systems to adapt. Unless governments finally start to act on these warnings, things will get much, much worse.”

A world moving in the wrong direction.

The 2022 Lancet Countdown report highlighted the opportunity to accelerate the transition from health-harming fossil fuels in response to the global energy crisis [2022 Report – Lancet Countdown]. However, this year’s report data reveal a world moving in the wrong direction.

New and updated indicators reveal that investment and lending on fossil fuels are on the rise. The carbon emissions of the global energy system (the most significant single contributor to global greenhouse gas emissions) grew by 0.9% in 2022 to a record 36.8 Gt, while governments keep incentivizing fossil fuel expansion. In 2020, 69 of 87 countries (responsible for 93% of all global carbon emissions) provided fossil fuel subsidies to the net value of $305 billion—exceeding 10% of national health spending in 26 countries and 50% in 10 countries.

The finance sector also contributes to growing health threats, with total private bank lending to fossil fuels reaching $572 billion in 2017-2021. The 40 private banks that lend the most to fossil fuels collectively invested US$489 billion every year between 2017 and 2021 in the industry, and over half increased their lending from 2010-2016, further hindering the zero-emission energy transition.

Together, the world’s 20 most significant oil and gas giants have increased their projected fossil fuel production levels since last year, which would result in greenhouse gas emissions surpassing levels compatible with 1.5°C of warming by 173% in 2040 (up from a 112% increase expected from their 2022 strategies), further reducing their compliance with the Paris Agreement. Concerningly, fossil fuel companies allocated just 4% of their capital investment to renewables in 2022, putting a healthy future further out of reach.

Meanwhile, the most underserved countries are being left behind in the clean energy transition, and inequitable access to clean energy has left the most vulnerable communities reliant on air-polluting fuels. Despite plentiful natural renewable energy resources, just 2.3% of electricity comes from clean renewables in low-income countries (compared with 11% in wealthy countries), and 92% of households still rely on polluting biomass (such as wood or dung) to cook and heat their homes (compared with 7.5% in wealthy nations).

“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 1.5°C target will not be achieved,

putting the health of millions of people at risk”, says Professor Paul Ekins, Lancet Countdown Working Group Lead on Economics and Finance. “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 incentivize the expansion and affordability of clean, renewable energy and activities that improve public health and resilience.”

Transformative opportunities of health-centred climate action

Despite the scale of the challenges, the report outlines the life-changing health benefits that could come from a health-centered transition to a zero-carbon future that prioritizes equity and justice within climate action.

At the heart of this ambition is a commitment to enabling and supporting an accelerated transition to clean energy and energy efficiency in low-income countries. “Empowering countries to transition from dirty fuels towards local, modern renewable sources of energy would bring not only immediate health benefits but also reduce socioeconomic and health inequities by developing local skills, generating jobs, supporting local economies, and delivering energy to off-grid areas to electrify homes and healthcare facilities, particularly in areas where energy poverty still undermines people’s health and wellbeing,” says Professor Ian Hamilton, Lancet Countdown Working Group Lead on Mitigation Actions and Health Co-benefits.

Simultaneously, improvements in air quality could prevent many of the 1.9 million deaths every year from exposure to fuel-derived outdoor air pollution and millions more from indoor air pollution.

Shifting to accessible active, public, and electric travel could avert many of the 460,000 deaths caused annually by travel-related PM2·5 emissions while improving health by supporting physical activity.

At the same time, accelerating a transition to healthier, low-carbon diets could prevent up to 12 million deaths due to poor diets every year, as well as reduce 57% of agricultural emissions from dairy and red meat production. These gains would also deliver healthier populations, reduce pressures on health systems, help minimize healthcare-related emissions, and promote health equity.

While swift action is urgently needed, there are some encouraging signs of progress, signaling what could be the start of a life-saving transition. This year’s report reveals that deaths from fossil fuel-derived air pollution have fallen almost 16% since 2005, with 80% of this decline due to efforts to reduce pollution from coal burning.

At the same time, global investment in clean energy grew 15% in 2022 to US$1.6 trillion, exceeding fossil fuel investment by 61%. Meanwhile, lending to the green energy sector rose to US$498 billion in 2021, approaching fossil fuel lending. As a result, renewable energy accounted for 90% of the growth in electricity capacity in 2022, and employment in renewables reached a record high with 12.7 million employees in 2021.

Ultimately, this year’s Lancet Countdown report solidifies the need for global collaboration and action on an unprecedented scale from governments, businesses, and the public. “While ambition to unlock money for adaptation will be critical, health-centered action requires urgent mitigation,” says Professor Anthony Costello, Co-Chair of the Lancet Countdown. “This will require defending people’s health from the interests of the fossil fuel and other health-harming industries. Transformative climate action is needed today to enable a future where present and future generations can thrive.”

Responding to the report publication, UN Secretary-General António Guterres (who was not involved in writing the report) says, “We are already seeing a human catastrophe unfolding with the health and livelihoods of billions across the world endangered by record-breaking heat, crop-failing droughts, rising levels of hunger, growing infectious disease outbreaks, and deadly storms and floods.

“The continuing expansion of fossil fuels is a death sentence to millions. There is no excuse for a persistent delay in climate action. Temperature rise must be limited to 1.5°C to avert the worst of climate change, save millions of lives, and help protect the health of everyone on earth.”