In this paper, we simulate how an increase in the productivity of the North-East Arctic cod fishery affects Russian–Norwegian cooperation on fish stock management. We link the productivity increase to sea environmental conditions and climate change through a temperature-dependent, stock–recruitment relationship, whereby the numbers of recruits positively relates to sea temperatures given the spawning stock biomass. The results indicate that the increased recruitment to and productivity of the stock increases the relative benefits of joint management compared with a noncooperative outcome.