With 2023 temperatures hitting record highs, climate-driven health crises are rising, endangering lives and putting immense pressure on global health systems.
Study: The 2024 report of the Lancet Countdown on health and climate change: facing record-breaking threats from delayed action. Image Credit: Fahroni/Shutterstock.com
The 2015 Paris Agreement aimed to protect the world from the severe health and economic impacts of rapid global warming by limiting temperature rise to within 1.5°C above pre-industrial levels. However, in 2023, the Earth’s surface temperature reached 1.45°C above this baseline. A recent article in The Lancet revisited the costs of this warming.
The authors, part of the Lancet Countdown—a collaborative initiative that tracks climate and health trends worldwide—provide an annual analysis of these impacts from global to national levels.
Human costs of climate change
In the latest year of data, 10 out of 15 climate-related health indicators showed record-breaking changes. For example, heat-related deaths among those over 65 rose by 167% compared to 1990s levels—significantly higher than the expected 65% increase without global warming.
Heat exposure, putting people at risk for heat stress, climbed by 27.7% compared to the 1990s, and sleep loss due to heat increased by 6% from the 1986–2005 baseline.
Extreme weather events had widespread effects, with record rainfall, flooding, epidemics, and water contamination impacting 61% of the Earth's land area, while drought lasting one or more months affected 48%. Food insecurity driven by drought and heatwaves affected 150 million more people in 2022 than previous years.
Additionally, 31% more people were exposed to hazardous air quality due to increased sand and dust storms. Rising temperatures and shifting rainfall patterns also accelerated the spread of diseases like dengue, malaria, West Nile virus, and cholera into new regions.
Economic loss due to climate change
Climate-related economic losses rose by 23% from 2013 to 2023. In wealthier countries, about 61% of these losses were covered by insurance, while in lower-income nations, most damages went uninsured, hitting local communities hardest.
Labor hours lost due to climate impacts reached a record 512 billion in 2023, valued at around $835 billion. This loss equates to 7.6% and 4.4% of the GDP in medium- and low-development countries, respectively, further burdening already vulnerable communities. Each fraction of a degree in global warming compounds these effects, with interconnected and cascading impacts on health.
However, only 68% of countries had fully implemented emergency response plans, and just 11% of these were high-income nations. Early warning systems for heat-related illnesses were available in 35% of countries, but only 10% had similar alerts for mental health impacts, with lack of funding cited as a primary barrier.
World off target to meet Paris goals
Despite the goals set by the Paris Agreement, carbon dioxide (CO₂) emissions from fossil fuels reached record highs in 2023 instead of declining. Emissions are expected to exceed targets by 189% by 2040, surpassing the projected increase of 173% in 2023.
Highlighting the limited progress toward a zero-emission future, fossil fuel industries employed 11.8 million people in 2022, and coal-burning power plants were valued at $164.5 billion, with the industry still expanding. Healthcare system emissions have also risen by 36% since 2016.
Renewable energy production remains insufficient, meeting just 2.3% of energy needs in the poorest countries compared to 11.6% in wealthier nations. In low-income regions, biomass burning supplies 92% of energy needs. Combined with fossil fuel use, which accounted for 67% of greenhouse gas (GHG) emissions in 2022, this contributed to 3.33 million deaths from outdoor air pollution with fine particulate matter in 2021, and 2.3 million deaths from indoor pollution due to polluting fuels. A decline in coal use in wealthier countries reduced deaths from this cause by 7%.
Deforestation continues at a rapid pace, with 182 million hectares lost from 2016 to 2022, shrinking one of the world’s main CO₂ sinks. Wealthy countries, such as Russia, the USA, and Canada, accounted for 64 million hectares of this loss, while developing countries contributed 42 million hectares.
Agricultural GHG emissions have increased by 2.9%, linked to rising red meat and dairy consumption, which contributed to 11.2 million diet-related deaths in 2021. Half of global CO₂ emissions originate from just two countries, China and the USA.
Climate adaptation and mitigation efforts remain underfunded, while fossil fuel companies, driven by profit, continue to expand production. This growth absorbs significant resources, including a record-breaking $1.4 trillion in global fossil fuel subsidies to stabilize fuel prices during the energy crisis.
Positive trends
Clean energy investment rose by 10% in 2023, 73% higher than. fossil fuel investment, but mostly (82.6%) in China and the developed economies.
By 2023, 50 countries had assessed health and climate vulnerabilities, and 43 had a Health National Adaptation Plan. Climate and health education was provided in 70% of public health institutions worldwide. Electricity contributed a record 10.5% of clean renewable energy, and employment in renewable energy increased by 35.6% during 2016-2022.
Current opportunities for climate change action
“The countries that have contributed least to rising temperatures are often most affected, and climate change is thereby exacerbating global inequities.”
The latest report outlines seven actionable opportunities based on 11 health-focused recommendations from the 2023 findings. It urges that all international agreements related to the Paris Accord integrate health into climate actions, including recognizing the health impacts and costs of climate change, as well as the health benefits of adaptation and mitigation.
Policies that gradually shift economies away from fossil fuel reliance, such as phasing out subsidies, are critical. Redirected spending could support climate adaptation and mitigation through clean energy investment, risk management, and targeted subsidies or transfers to assist the most vulnerable countries and communities.
The upcoming Nationally Determined Contributions (NDCs) in 2025, along with the financial loss-and-damage fund and the New Collective Quantified Goal on Climate Finance determined at COP29, should prioritize health impacts. Additionally, assessment metrics for climate-linked losses and gains must be health-focused.
Instead of continued investment in fossil fuels, which will eventually need to be phased out, the transition to renewable energy must accelerate, with an emphasis on health outcomes, as highlighted by the Just Transition Work Program.
Public health initiatives that reduce greenhouse gas emissions, limit pollution, and encourage healthy diets should be integrated into climate policies. Engaging traditional Indigenous wisdom is also essential, as it often offers valuable insights into sustainable health and environmental practices.
For these strategies to be effective, international health leaders need to champion the integration of health within climate action frameworks.
Conclusion
With little serious intention on preventing the catastrophic consequences of climate change on human health and survival, health professionals need to actively engage with decision-makers at all levels to steer policies away from hazardous activities towards those that support health and resilience.
Sleep disruptions may increase brain volume in the hippocampus