Motives for fishing differ among fishers, which may imply different effects of climate change on the net values of fishing. Climate change has impacts on fish population dynamics and on other factors in the fishers’ harvest decision, such as alternative sources of food or income. Here we present a bio-economic model that includes impacts of climate change on fish population and on net values of harvest by fishers with recreational or subsistence fishing motives. The conceptual analysis shows that the economic effects of climate change with simultaneous impacts on fish population growth and harvest values are inconclusive with common fishing access for both fisher types and when there are opposite simultaneous climate effects with exclusive access for one of the fisher types. Numerical results from our model of Arctic char (Salvelinus alpinus) in northern Sweden indicate that climate change, measured as temperature increases, reduces fish population growth but increases net values of fishing for both fisher types. The combined net effect of these counteracting forces is that annual net values can almost cease for the subsistence fisher in the future but increase considerably for the recreational fisher.