With climate change underway, mitigation and adaptation strategies are required to limit the impacts of future climate change on food, water and energy. While a large number of studies have been devoted to understanding and simulating future climate impacts, they generally rely on a small ensemble of climate simulations and do not consider all major sources of uncertainty in future projections of regional climate change. In this presentation, we investigate the role of four major sources of uncertainty, namely: emissions projections; the climate system response; natural variability; and climate models' structural uncertainty. In light of the results presented here, we provide some recommendations on the treatment of climate uncertainty in climate impact studies at the regional scale.