Abstract:  Excerpts from the Executive Summary

During 2021 and 2022, extreme weather events caused devastation across every continent, adding further pressure to health services already grappling with the impacts of the COVID-19 pandemic. Floods in Australia, Brazil, China, western Europe, Malaysia, Pakistan, South Africa, and South Sudan caused thousands of deaths, displaced hundreds of thousands of people, and caused billions of dollars in economic losses. Wildfires caused devastation in Canada, the USA, Greece, Algeria, Italy, Spain, and Türkiye, and record temperatures were recorded in many countries, including Australia, Canada, India, Italy, Oman, Türkiye, Pakistan, and the UK. With advancements in the science of detection and attribution studies, the influence of climate change over many events has now been quantified. Because of the rapidly increasing temperatures, vulnerable populations (adults older than 65 years, and children younger than one year of age) were exposed to 3·7 billion more heatwave days in 2021 than annually in 1986–2005 (indicator 1.1.2), and heat-related deaths increased by 68% between 2000–04 and 2017–21 (indicator 1.1.5), a death toll that was significantly exacerbated by the confluence of the COVID-19 pandemic. Simultaneously, the changing climate is affecting the spread of infectious diseases, putting populations at higher risk of emerging diseases and co-epidemics. Coastal waters are becoming more suitable for the transmission of Vibrio pathogens; the number of months suitable for malaria transmission increased by 31·3% in the highland areas of the Americas and 13·8% in the highland areas of Africa from 1951–60 to 2012–21, and the likelihood of dengue transmission rose by 12% in the same period (indicator 1.3.1). The coexistence of dengue outbreaks with the COVID-19 pandemic led to aggravated pressure on health systems, misdiagnosis, and difficulties in management of both diseases in many regions of South America, Asia, and Africa.

A debilitated first line of defence:  With the worsening health impacts of climate change compounding other coexisting crises, populations worldwide increasingly rely on health systems as their first line of defence. However, just as the need for healthcare rises, health systems worldwide are debilitated by the effects of the COVID-19 pandemic and the energy and cost-of-living crises. Urgent action is therefore needed to strengthen health-system resilience and to prevent a rapidly escalating loss of lives and to prevent suffering in a changing climate. However, only 48 (51%) of 95 countries reported having assessed their climate change adaptation needs (indicator 2.1.1) and, even after the profound impacts of COVID-19, only 60 (63%) countries reported a high to very high implementation status for health emergency management in 2021 (indicator 2.2.4). The scarcity of proactive adaptation is shown in the response to extreme heat. Despite the local cooling and overall health benefits of urban greenspaces, only 277 (27%) of 1038 global urban centres were at least moderately green in 2021 (indicator 2.2.3), and the number of households with air conditioning increased by 66% from 2000 to 2020, a maladaptive response that worsens the energy crisis and further increases urban heat, air pollution, and greenhouse gas emissions. As converging crises further threaten the world’s life-supporting systems, rapid, decisive, and coherent intersectoral action is essential to protect human health from the hazards of the rapidly changing climate.