The causal link between economic growth and environmental degradation has received much attention in recent social science literature(s). Although such studies have generated key insights, the role of monetary systems – as central components of all modern economies – has been almost completely overlooked. This papers argue that monetary systems affect natural environments through the economic activities that particular monetary systems promote. It focuses on two specific aspects of any monetary system: governance and scale. With respect to the former, it shows how the rules that govern monetary systems can promote economic practices with environmental implications. With respect to the latter, the paper shows how the scale at which money is issued and/or circulates affects patterns and intensities of economic activity, both of which have clear environmental consequences. A corollary of the argument is that changing the governance and scale of monetary systems can alter economic activity in environmentally-harmful or -helpful ways.