Significance: Agricultural methane emissions must be decreased by 11 to 30% of the 2010 level by 2030 and by 24 to 47% by 2050 to meet the 1.5 °C target. We identified three strategies to decrease product-based methane emissions while increasing animal productivity and five strategies to decrease absolute methane emissions without reducing animal productivity. Globally, 100% adoption of the most effective product-based and absolute methane emission mitigation strategy can meet the 1.5 °C target by 2030 but not 2050, because mitigation effects are offset by projected increases in methane. On a regional level, Europe but not Africa may be able to meet their contribution to the 1.5 °C target, highlighting the different challenges faced by high- and middle- and low-income countries.

Climate change has intensified the need to reduce greenhouse gas emissions, particularly methane (CH ₄ ) from enteric fermentation. Genetic selection has emerged as a promising mitigation strategy; however, studies on Bos taurus indicus , especially Nellore cattle, remain limited. This study aimed to estimate heritabilities and genetic correlations for CH ₄ emission traits and their relationships with feeding behaviour, feed efficiency, and performance, as well as to evaluate the direct and correlated responses to selection for lower CH ₄ emissions. Data were from 2418 Nellore cattle evaluated in feed efficiency trials. Traits included dry matter intake (DMI), feeding time per day (FTd), feed events per day (FEd), and feeding rate (FR), residual feed intake (RFI), average daily gain (ADG), and mid‐test body weight (MBW). Methane emissions were measured in 1153 animals using the SF ₆ tracer technique, providing daily CH ₄ emission (g/day), CH ₄ per unit of DMI (CH ₄ DMI, g/day), and residual CH ₄ (CH ₄ res). Variance components were estimated using the single‐step genomic BLUP (ssGBLUP) method through Bayesian inference. Heritability estimates were moderate for CH ₄ (0.25), CH ₄ DMI (0.14), CH ₄ res (0.14), and performance traits such as DMI (0.35), ADG (0.36), and MBW (0.40). Higher estimates were observed for feeding behaviour traits FTd (0.49) and FR (0.42). Genetic correlations between CH ₄ and production traits were high, particularly with DMI (0.79), ADG (0.90), and MBW (0.91), indicating that selection for reduced CH ₄ emissions may affect growth. Direct selection for CH ₄ led to a modest annual reduction in emissions but also a correlated decline in MBW. These results demonstrate that while CH ₄ emissions are heritable, their strong genetic association with productivity traits indicates that isolated selection for reduced emissions may lead to undesirable outcomes in feed intake and performance. Therefore, strategies aiming to reduce CH ₄ emissions should consider the genetic relationships with growth and efficiency traits to avoid compromising animal productivity.