Democratic myopia, lacking salience, and high uncertainty seem to make it difficult to govern long-term problems like climate change, biodiversity loss or the environmental consequences of infrastructure projects. Participatory approaches may benefit environmental decisions, but the literature largely neglects the implications of the long-termness of many environmental issues. Conversely, the literature on long-term governance disregards the potential of participation to solve long-term problems. To address this gap, this study develops a new conceptual framework and statistically analyzes 303 cases of public environmental decision-making processes to assess the role of participatory governance in addressing long-term environmental problems. The results show that participatory governance indeed helps to solve and prevent long-term environmental problems – but in different ways than it addresses short-term environmental problems. Intensive deliberation proves key for effectively adressing long-term issues, while the representation of environmental and economic interests in the process makes no difference for the environmental standard of the governance output. The opposite is true for short-term environmental problems. Surprisingly, issue uncertainty, while higher in long-term issue settings, does not affect the solution of long-term but only of short-term environmental problems. In general, deliberation seems to be more decisive than participation for effectively addressing long-term environmental problems.