This review article examines the role of methane in global warming, focusing on the contribution of enteric fermentation, primarily from ruminants. It highlights that agricultural emissions of methane in the EU-15 amount to approximately 10.2 million tonnes per year, with two-thirds coming from enteric fermentation and one-third from livestock manure. The rumen is the primary source of methane, and the molar percentage of different volatile fatty acids produced during fermentation influences methane production. Acetate and butyrate promote methane production, while propionate formation competes with hydrogen use in the rumen. The article discusses various strategies to reduce methane emissions, including the development of new products or delivery systems for anti-methanogenic compounds, promoting alternative electron acceptors, and reducing protozoal numbers in the rumen. It emphasizes that ruminants are crucial for converting fibrous biomass into high-quality protein sources like meat and milk, which must be balanced against their methane emissions. The review also covers the greenhouse effect, the consequences of increased atmospheric methane, and the role of methane in global warming. It details the sources and sinks of methane, with agriculture being the largest contributor. The article outlines the European post-Kyoto policy recommendations and the importance of reducing methane emissions from agricultural activities. Finally, it explores the microbial processes involved in methane production and the impact of feeding characteristics on methane emissions. It discusses mitigation scenarios, including direct inhibition of methanogenesis, use of ionophores, propionate enhancers, stimulation of acetogens, methane oxidizers, defaunation, probiotics, and immunization. The article concludes by suggesting that increasing animal productivity through better diet management and genetic improvement can reduce methane emissions per unit of product.This review article examines the role of methane in global warming, focusing on the contribution of enteric fermentation, primarily from ruminants. It highlights that agricultural emissions of methane in the EU-15 amount to approximately 10.2 million tonnes per year, with two-thirds coming from enteric fermentation and one-third from livestock manure. The rumen is the primary source of methane, and the molar percentage of different volatile fatty acids produced during fermentation influences methane production. Acetate and butyrate promote methane production, while propionate formation competes with hydrogen use in the rumen. The article discusses various strategies to reduce methane emissions, including the development of new products or delivery systems for anti-methanogenic compounds, promoting alternative electron acceptors, and reducing protozoal numbers in the rumen. It emphasizes that ruminants are crucial for converting fibrous biomass into high-quality protein sources like meat and milk, which must be balanced against their methane emissions. The review also covers the greenhouse effect, the consequences of increased atmospheric methane, and the role of methane in global warming. It details the sources and sinks of methane, with agriculture being the largest contributor. The article outlines the European post-Kyoto policy recommendations and the importance of reducing methane emissions from agricultural activities. Finally, it explores the microbial processes involved in methane production and the impact of feeding characteristics on methane emissions. It discusses mitigation scenarios, including direct inhibition of methanogenesis, use of ionophores, propionate enhancers, stimulation of acetogens, methane oxidizers, defaunation, probiotics, and immunization. The article concludes by suggesting that increasing animal productivity through better diet management and genetic improvement can reduce methane emissions per unit of product.