Abstracts - Environnement

Achieving global climate targets requires accurate quantification of greenhouse gas (GHG) emissions and their implied impact on temperature. However, the choice of emission metric—particularly between Global Warming Potential over 100 years (GWP100) and Global Warming Potential Star (GWP*)—can significantly influence how emissions and their contributions to global warming are represented in climate assessments. While metrics do not alter physical temperature outcomes, they affect how emissions’ impacts are interpreted, which in turn influences carbon dioxide removal estimates and mitigation strategies. Using FAO projections for global livestock emissions to 2050, we analyze how different metric choices affect estimates of the carbon dioxide removal required to offset methane (CH₄) emissions and achieve no additional warming condition. Our findings highlight that GWP100 can overestimate or underestimate the cumulative warming impact of CH₄ emissions under different emission trajectories, whereas GWP* provides a dynamic approach that better aligns with temperature goals. These differences have critical implications for climate policy, as they influence the perceived effectiveness of mitigation strategies and the allocation of carbon dioxide removal requirements. This study underscores the necessity of selecting appropriate metrics when designing climate mitigation frameworks, particularly for methane-intensive sectors like livestock, to ensure an accurate representation of their contribution to global temperature targets.

This article explores the scientific, technical, ethical and social issues related to the production of cell-based foods, such as “cultured meat”. Based on FAO and WHO publications, it identifies key research gaps, especially in the social sciences. It also emphasizes the need for neutral, comparable, and accessible data to support informed decision-making by stakeholders.

According to life cycle assessment (LCA), meat from ruminant species has a higher environmental impact per kg of protein than meat from monogastric species. Conversely, the framework of ecosystem services (ES) indicates that ruminant farming systems can provide higher levels of regulating ES (e.g. water purification). We applied both approaches to twelve contrasting meat production systems (six ruminant, six monogastric). The LCA was applied using two ‘functional units’: i) the quantity of protein produced (kg) and ii) the land area used to produce the meat (m²/year). Our results confirm that, per kg of protein, ruminant systems emit more greenhouse gases and consume more energy than monogastric systems, but the opposite is observed of land area. Ruminant systems also provide more regulating ES, thanks to their grasslands. Our study reveals that LCA and ES approaches can converge or diverge depending on the functional unit used.

Reducing greenhouse gas (GHG) emissions, particularly enteric methane (CH₄) from cattle, is a key challenge in achieving carbon neutrality by 2050. The Methane 2030 program (2023–2028) addresses this issue by pursuing a 30% reduction in CH₄ emissions from French cattle farming within ten years, while maintaining milk and meat production levels. Combining a network of experimental farms and commercial herds, the program uses multiple measurement and estimation methods to develop reference data and identify effective low-emission strategies. Several levers are explored, including feeding practices, nutritional additives, genetic improvement, and herd management innovations. Coordinated by a consortium of industry, research, and development partners, Methane 2030 will deliver an integrated “toolbox” for emission mitigation. Built around the CAP’2ER® assessment tool, genomic selection, and livestock advisory services, this toolbox will provide practical and science-based solutions to support sustainable, low-emission cattle production systems in France.

In 2022, the Dublin Declaration on the societal role of livestock farming encouraged animal scientists to alert policymakers and the public to the importance of basing dietary recommendations and promoting an image of livestock farming on sound scientific evidence. In October 2024, animal, environment and social scientists renewed and deepened their commitment by publishing the Denver Call to Action https://www.dublin-declaration.org/fr/lappel-a-action-de-denver at the Second International Summit on the Societal Role of Meat and Livestock, where current scientific knowledge about livestock farming was presented in a synthetic manner. This call is addressed to policymakers worldwide to commit to plurality and rigor in evidence-based decision-making.

The Dublin Declaration on the Societal Role of Livestock Farming encouraged scientists in the field to alert policy-makers and the public to the importance of basing dietary recommendations and promoting an image of livestock farming on sound scientific evidence. They do this conscientiously, even if they become the target of militant campaigns aimed at discrediting disturbing scientific voices. Certainly, divergent views have been expressed on the best way to implement scientific findings, or on the optimum nature or size of future livestock systems. However, there is a firm consensus on the crucial importance of maintaining rigorous scientific approaches for an informed debate on livestock farming. This context prompted animal scientists to renew their commitment by publishing the Denver Call to Action. This was done on the occasion of the second International Summit on the Societal Role of Meat and Livestock in Denver in October 2024, where scientific knowledge about livestock farming was presented. This call is addressed to political decision-makers around the world to commit to plurality and rigor in evidence-based decision-making. Meeting the colossal challenge of feeding the world's populations while minimizing environmental damage will only be possible through the transparent application of scientific rigor, avoiding hubris, presumption and dogmatism.