Physical economic activities have traditionally been organised in a linear fashion, with resources that start as raw materials being accessed and then transformed into outputs which include both desired products and undesired waste. This architecture relies on three conditions: the ability to source inputs; their price; and the hope that the market (and more broadly, society) 15welcomes the outputs. The present chapter will analyse the first stage of this process, namely the availability of resources. The book’s next chapter will then look at one aspect of its second stage, specifically the treatment of unwanted outputs known as pollution. These two topics embody the main challenges that modern green business purports to address.