One health benefits of five European countries adopting 1.5 °C lifestyles

• The prospective analysis addresses impacts on human, animal, and ecosystem health. • The animal welfare assessment covers farmed terrestrial and aquatic animals. • 1.5 °C lifestyles yield substantial co-benefits for One Health. • The impact reductions occur worldwide and mostly outside the EU case countries. • The most beneficial lifestyle options are related to mobility and nutrition. The links between human, animal, and ecosystem health call for their integration in a One Health approach. Climate change can have severe impacts on all three dimensions. Such impacts stress the need to limit global warming to 1.5 °C, and lifestyle changes are essential in complementing supply-side changes to meet this climate target. Using multiregional input–output analysis, we assessed the One Health impacts of lifestyle changes in 2030 across five diverse European countries: Germany, Hungary, Latvia, Spain, and Sweden. The greenhouse gas emissions savings resulting from 1.5 °C lifestyles were translated into changes in heat and cold stress affecting human health, as well as changes in potential wild freshwater fish species loss representing ecosystem health. Animal health was approximated by the raw and morally adjusted numbers of farmed animals embodied in household consumption. 1.5 °C lifestyles yield substantial co-benefits for One Health. Germany yields the largest co-benefits for human and ecosystem health and, in relative terms, also for animal health when considering moral adjustment, while Sweden yields the largest co-benefits for animal health in absolute terms. The impact reductions occur worldwide and predominantly outside the countries studied. The options most beneficial to human and ecosystem health are related to mobility, and those most beneficial to animal health are related to nutrition. The demonstrated co-benefits of 1.5 °C lifestyles for One Health increase the relevance and motivation for engaging in climate change mitigation efforts.