The World Health Organization (WHO) and authors of the new Lancet Countdown report highlight an unprecedented rise in threats to human health due to climate change. On average globally, people were exposed to a record 16 additional days of extreme heat that threaten health and «can be directly attributed to climate change». The most vulnerable groups (infants under one year and adults over 65) experienced a historic high of 20 days of extreme heat, a 389% and 304% increase, respectively, compared to the 1986-2005 average. The report states that heat-related mortality per 100,000 people has increased by 23% since the 1990s, reaching an average of 546,000 deaths annually between 2012 and 2021. Warmer and drier conditions have also fueled wildfires, where fine particulate matter (PM2.5) pollution from smoke resulted in a record 154,000 deaths in 2024, a 36% increase from the 2003-2012 annual average. Meanwhile, the average potential for dengue transmission worldwide has increased by 49% since the 1950s. In 65 countries with limited access to clean energy, air pollution from the domestic use of dirty fuels resulted in 2.3 million preventable deaths in 2022. More broadly, the report emphasizes that climate change is increasingly destroying livelihoods, straining the economy, and burdening health budgets. Exposure to heat is linked to a record 639 billion potential hours of lost labor productivity in 2024. Additionally, the costs of heat-related deaths in those over 65 reached a historic high of $261 billion. Alarmingly, 15 of the 87 countries responsible for 93% of global CO2 emissions spent more on net fossil fuel subsidies than on their national health budgets in 2023. These are: Algeria, Angola, Azerbaijan, Bahrain, Venezuela, Brunei Darussalam, Egypt, Iraq, Iran, Kazakhstan, Kuwait, Libya, Saudi Arabia, Turkmenistan, and Uzbekistan. The report also states that «emboldened by rising profits and the fracturing of political consensus, the world's 100 fossil fuel giants increased their projected production (as of March 2025), which would lead to their greenhouse gas emissions almost tripling levels compatible with 1.5 degrees by 2040». Private banks are «supporting this lethal expansion», with the top 40 lenders in the fossil fuel sector collectively investing the highest amount in five years, $611 billion in 2024 (a 29% increase from 2023). These extreme events caused economic losses of nearly $19.2 billion in 2022. «We are very concerned,» summarized Marina Romanello, executive director of the initiative at University College London (UCL), at a press conference. While some national governments are backtracking on climate commitments, the report highlights that local executives, individuals, civil society, and the health sector are leading the way. For example, the health sector itself has demonstrated «impressive leadership» by showing a 16% reduction in health-related greenhouse gas emissions globally between 2021 and 2022. The authors of the report claim that 2.5 million deaths annually are attributable to air pollution from the continuous burning of fossil fuels. 2024 was the hottest year on record with catastrophic consequences. «The harsh reality is that one of the greatest threats to human prosperity comes from leaders and companies who are backtracking...», laments Nadia Ameli, co-chair of one of the working groups. The optimism, however, comes from the closest circles.
