The design of environmental policy typically takes place within a framework in which uncertainty over the future impact of pollution and two different kinds of irreversibilities interact. The first kind of irreversibility concerns the sunk cost of environmental degradation; the second is related...

We consider an optimal consumption and pollution problem that has two important features. Environmental damages due to economic activities may be irreversible and the level at which the degradation becomes irreversible is unknown. Particular attention is paid to the situation where agents are...