Met Éireann, in collaboration with UCD, has been running a regional climate modelling project since 2003, producing an ensemble of climate forecasts for the coming decades for Ireland. The rationale behind this method and the computer resources required to produce multi-decadal climate simulations are discussed. An overview of the simulation outputs is presented, including their use in application models to assess the future risks from climate change for Ireland. The reliability of climate predictions and work that is currently underway to reduce this uncertainty is also discussed.