Democratic myopia, lacking salience, and high uncertainty seem to make it difficult to govern long-term problems like nuclear waste disposal, 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 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 mere participation for effectively addressing long-term environmental problems.