From soaring heart attack rates and debilitating heat exhaustion to profound mental health challenges and the relentless spread of tropical illnesses, the climate crisis is increasingly endangering lives across the globe. A recent report, released by 128 leading scientists behind the comprehensive Lancet Countdown Report, issues a stark warning: the repercussions of escalating global temperatures are now more perilous to human health than ever before.
Marina Romanello, the executive director of the Lancet Countdown, an esteemed international research collaboration based at University College London, emphasizes the gravity of the situation. “This year’s health assessment paints a grim and undeniable picture of the devastating health harms reaching every corner of the world,” she states.
The analysis reveals a shocking 23% surge in heat-related deaths since the 1990s, with rising temperatures now claiming over half a million lives annually. In 2024 alone, wildfire smoke was tragically linked to a record-breaking 154,000 deaths, while air pollution from the continuous burning of fossil fuels continues to take an alarming 2.5 million lives each year.
Health Risks Intensified Last Year
Romanello articulates the profound tragedy: “We’re witnessing millions of deaths occurring needlessly every year due to our persistent reliance on fossil fuels, our delays in mitigating climate change, and our slowness in adapting to the climate changes that are now unavoidable.”
The Lancet Countdown report is widely recognized as a crucial benchmark for understanding the scientific connections between human health and global warming. These links are becoming increasingly stark as climate change, primarily driven by the combustion of coal, oil, and gas, continues to wreak havoc worldwide.
Last year marked the warmest on record, with carbon dioxide levels in the atmosphere reaching unprecedented highs. Consequently, the average individual experienced an additional 16 dangerously hot days directly attributable to climate change. For society’s most vulnerable, such as infants and those over 65, this figure surged to an average of 20 extra heatwave days.
The report highlights that a concerning 13 out of 20 indicators assessing human health risks have significantly worsened over the past year. Romanello underscores the alarming trend, stating that nearly all indicators are heading in the wrong direction.
The Mounting Health and Economic Costs
Climate change is intensifying extreme weather events, making them more frequent and severe globally. Heatwaves, recognized as the deadliest form of extreme weather, can lead to severe overheating, strain vital organs, and disrupt sleep. Catastrophic flooding, like that experienced in regions such as Pakistan this year, can contaminate drinking water supplies and facilitate the rapid spread of infections. Meanwhile, prolonged droughts exacerbate malnutrition and hunger as essential crops fail.
Smoke from widespread wildfires, which in 2024 consumed an area larger than India, causes severe damage to lungs, hearts, and even poses risks to unborn babies. In the aftermath of these weather-related disasters, power outages and damaged infrastructure can severely impede access to critical medical care and essential supplies. Romanello points out that a significant portion of those affected by extreme weather globally lack health insurance, making them even more susceptible to the devastating health consequences.
These widespread risks are not only claiming human lives but also imposing substantial economic burdens. Water and food shortages, along with dire sanitary conditions following disasters, incur hundreds of billions of US dollars annually. Extreme heat alone is estimated to have cost over one trillion US dollars in 2024, representing approximately 1% of global economic output, primarily due to labor losses from illness and absenteeism.
Dengue and Tropical Diseases on the Rise
As global temperatures continue to climb, disease-carrying insects like mosquitoes, ticks, and sand flies are expanding their habitats, reaching new regions. Last week, for instance, mosquitoes were recorded for the very first time on the northern European island of Iceland, a phenomenon directly linked by researchers to climate change.
With warmer conditions creating new breeding grounds, the number of people contracting dengue, malaria, leishmaniasis, and other infectious diseases is increasing worldwide. In 2024, a record 7.6 million cases of dengue were reported globally. “We know that climate change is fueling at least some of that spread,” Romanello confirms. Even if these infections are not always fatal, those who fall ill often face weeks of incapacitation, leading to significant economic setbacks.
According to the report, the global average transmission potential of dengue has risen by an alarming 49% since the 1950s.
Mental Health Also Under Attack
Beyond physical ailments, climate change is also heightening the risk of mental illness. Experiencing extreme weather events such as wildfires, hurricanes, monsoons, typhoons, or severe flooding can trigger post-traumatic stress disorder (PTSD), explains Jenni Miller, executive director of the Global Climate and Health Alliance, a US non-governmental organization.
Moreover, poor harvests resulting from droughts, water scarcity, or a loss of livelihood can induce anxiety and directly or indirectly contribute to mental health problems. This challenging situation is further compounded by a lack of restorative sleep caused by increasingly hot nights, as noted in the report.
Urgent Action to Prevent Further Illness and Death
The report’s authors advocate for three crucial measures to mitigate the severe health consequences of the climate crisis:
- **Rapid Expansion of Renewable Energy:** It is imperative to accelerate the transition to renewable energy sources to effectively curb rising global temperatures. Clean energy, which has seen significant growth in recent years, has already demonstrated its positive impact, helping to reduce air pollution and prevent over 160,000 deaths between 2010 and 2022, according to Romanello.
- **Accelerated Climate Adaptation Measures:** Efforts to adapt to climate change must be intensified. This includes making residential buildings and public infrastructure resilient to extreme weather conditions.
- **Strengthening Global Healthcare Systems:** Global healthcare systems require urgent adaptation and equipping to adequately meet the additional health challenges presented by climate change.