 The Maia Maia Emissions Reduction Currency System, is a scheme developed in Western Australia.The system currency is known as a "boya", named after the indigenous Nyungar people's word for rock trading tokens used by them.Each boya is based on 10 kilograms of carbon dioxide equivalent global warming prevention which is equates to a $100 tonne CO2-e Social Cost of Carbon, which approximates a middle estimate from peer reviewed studies.