The UK and Ireland both have large greenhouse gas (GHG) reduction targets under the EU Effort Sharing Decision (ESD). The ESD covers non-emission trading sector (Non-ETS) emissions, of which agriculture is an important component, representing 44% of the non-ETS emissions for Ireland. In the UK this figure is lower, at 16%, but the composition varies significantly between the constituent countries. Though the reductions targets and means of achieving them differ, reductions in agricultural emissions will be necessary for both the UK and Ireland, and on-going negotiations setting reductions targets for 2030 are likely to result in even stricter limits for emissions from the non ETS sector. This paper examines the implications of achievement of possible 2020 and 2030 GHG reductions targets in the agriculture sector for the UK and Ireland. The paper considers the achievability of the reduction targets based on technical means alone, suggesting that under current carbon budgets the UK aims to make sufficient agricultural emissions reductions, while Ireland will require a reduction in agricultural activity or alternative policy interventions. The implications for food production in the UK and Ireland and associated trade are then assessed.