Global pet ownership, especially of cats and dogs, is rising with income growth, and so too are the environmental impacts associated with their food. The global extent of these impacts has not been quantified, and existing national assessments are potentially biased due to the way in which they account for the relative impacts of constituent animal by-products (ABPs). ABPs typically have lower value than other animal products (i.e. meat, milk and eggs), but are nevertheless associated with non-negligible environmental impacts. Here we present the first global environmental impact assessment of pet food. The approach is novel in applying an economic value allocation approach to the impact of ABPs and other animal products to represent better the environmental burden. We find annual global dry pet food production is associated with 56–151 Mt CO₂ equivalent emissions (1.1%−2.9% of global agricultural emissions), 41–58 Mha agricultural land-use (0.8–1.2% of global agricultural land use) and 5–11 km³ freshwater use (0.2–0.4% of water extraction of agriculture). These impacts are equivalent to an environmental footprint of around twicethe UK land area, and would make greenhouse gas emission from pet food around the 60th highest emitting country, or equivalent to total emissions from countries such as Mozambique or the Philippines. These results indicate that rising pet food demand should be included in the broader global debate about food system sustainability.

全球宠物拥有量，尤其是猫和狗的拥有量随着收入的增长而增加，与食物相关的环境影响也是如此。这些影响的全球范围尚未量化，现有的国家评估可能由于考虑了构成动物副产品（ABP）的相对影响而存在偏差。ABP的价值通常低于其他动物产品（即肉，牛奶和鸡蛋），但与不可忽视的环境影响相关。在这里，我们介绍了宠物食品的首次全球环境影响评估。该方法在将经济价值分配方法应用于ABP和其他动物产品的影响以更好地代表环境负担方面是新颖的。我们发现全球每年干宠物食品的生产与56–151 Mt CO相关₂当量排放（占全球农业排放的1.1％-2.9％），41-58 Mha的农业土地利用（占全球农业土地的0.8-1.2％）和5-11 km ^3的淡水利用（占水提取量的0.2-0.4％）农业）。这些影响相当于英国陆地面积的两倍左右，并将使宠物食品的温室气体排放量排在排放量最高的60个国家附近，或相当于莫桑比克或菲律宾等国家的总排放量。这些结果表明，不断增长的宠物食品需求应纳入有关食品系统可持续性的更广泛的全球辩论中。