The future consequence of climate change on biodiversity is a highly complex, where species ability to follow their range shift plays a major part. A warmer climate will not enable the butterfly Pyrgus armoricanus to expand further north, but it could potentially increase the population size and inhabited area in Sweden. The European population could be expected to become more fragmented since habitat are predicted to decrease due to land use change (Thuiller, et al., 2005; Lehsten, et al., 2015) simultaneously as habitat in southern Europe becomes unsuitable due to a warmer climate (Settele, et al., 2008). The overall effect of decreasing habitat availability and inability to spread north could be lead to species extinction. This displays the importance of not assuming that a species could expand north simply because their climatic range shifts. This simple approach used in this study could be a first step to evaluate a species range shift ability and estimate its vulnerability to climate change. This study also highlights that some traits has great influence on a species range shift ability, especially growth rate, dispersal ability and habitat specialization. The diverging ability for species to follow their range shift could lead to a future biodiversity impoverishment, dominated by generalist species with high growth rate and dispersal ability.