Carbon, cash, cattle and the climate crisis

While society increasingly demands emissions abatement from the livestock sector, farmers are concurrently being forced to adapt to an existential climate crisis. Here, we examine how stacking together multiple systems adaptations impacts on the productivity, profitability and greenhouse gas (GHG) emissions of livestock production systems under future climates underpinned by more frequent extreme weather events. Without adaptation, we reveal that soil carbon sequestration (SCS) in 2050 declined by 45-133%, heralding dire ramifications for CO 2 removal aspirations associated with SCS in nationally-determined contributions. Across adaptation-mitigation bundles examined, mitigation afforded by SCS from deep-rooted legumes was lowest, followed by mitigation from status quo SCS and woody vegetation, and with the greatest mitigation afforded by adoption of enteric methane inhibitor vaccines. Our results (1) underline a compelling need for innovative, disruptive technologies that dissect the strong, positive coupling between productivity and GHG emissions, (2) enable maintenance or additional sequestration of carbon in vegetation and soils under the hotter and drier conditions expected in future, and (3) illustrate the importance of holistically assessing systems to account for pollution swapping, where mitigation of one type of GHG (e.g. enteric methane) can result in increased emissions of another (e.g. CO 2). We conclude that transdisciplinary participatory modelling with stakeholders and appropriate bundling of multiple complementary adaptation-mitigation options can simultaneously benefit production, profit, net emissions and emissions intensity.