18This numerical example has demonstrated that the perverse effect of implementing a cleaner tech-nology is not a mere theoretical possibility within the context of climate change. It is shown to be strongfor a significant and empirically relevant range of parameters. It is when the damage is relatively largeand/or the initial stock of pollution are relatively large and when the natural rate of decay of pollutionis relatively ‘small’, i.e. precisely the situations where the tragedy of the commons is at its worse, thatthe perverse effect prevails.