BACKGROUND :

Climate change is one of humanity’s most serious threats, putting at risk the functioning of the natural systems that sustain human health. In the Anthropocene, human activities have significantly altered the Earth through global warming, habitat loss and changes to the atmosphere. Based on a moderate emissions scenario that reflects little change from today’s development patterns, the average global temperatures will rise by 2.1–3.5 °C from preindustrial levels, which is above the 1.5–2 °C threshold set by the 2015 Paris Agreement. Although many countries committed to reduce carbon emissions and waste at the 26th United Nations Climate Change Conference and still aim at net-zero emissions, these commitments are insufficient to reach the target of keeping global warming within 1.5 °C above preindustrial levels. Despite scientific evidence, the gap between what we know and what we do in practice and political inaction continue to prevail. The co-occurrence and synergistic interaction of climate change, loss of biodiversity and effects on food production have an exponential multiplier effect on human health compared to when these conditions are experienced separately. For example, food production and processing, retail, distribution and consumption, as well as food waste, contribute to climate change through the emissions of greenhouse gas. In turn, climate change affects food production and diversity and increases food insecurity, leading to overnutrition, undernutrition and deficiencies in micronutrients, particularly among children and vulnerable groups. Exposure to air pollutants increases all-cause, cardiovascular and respiratory morbidity and mortality, including lung cancer; effects are more significant among vulnerable subgroups. Changes in temperature and precipitation, and more frequent natural disasters are major factors of increased biodiversity loss. Meat production, intensive land use for agriculture and climate change also explain the decline in biodiversity. Intensive land use exposes humans to novel pathogens in wildlife and climate change alters host– vector–pathogen interactions, all of which increase risks of zoonotic diseases. While many health researchers focus on the implications of climate change on health and socioeconomic inequities, there remains much to understand about the repercussion of climate change on biodiversity, food production and human health. The Bulletin of the World Health Organization calls for papers that address two broad and interlinked areas. First, the impact of climate change on biodiversity, food and nutritional security and human health. Second, effective policies and promising interventions that prevent, mitigate and provide alternative food production systems to minimize the health effects of these interlinked determinants. Analysis of the root causes of inaction in policies against climate change and its effects can contribute to effective policy levers.