Environmental issues have become ubiquitous, and so has the term sustainability. A plethora of policies, companies, customers, investors, NGOs, and societies discuss sustainability; but talking and acting are two entirely different realms. The corporate sector, as one of the main polluters, bears a special responsibility to behave and act sustainably. Many companies state that they care about sustainability. However, sustainability is often not actually implemented into the company's culture and actions, but may represent a tool for looking good to the outside. In order to truly ingrain sustainability, there is a need to have specific internal instruments that track the firm's environmental performance. This is where indicators come into the picture - more precisely environmental indicators. These are useful tools which may be applied by the accounting function in a firm in order to track its environmental performance and to support the decision-making of the management. However, in order to be useful they first have to be accepted and implemented, and unfortunately up until now, environmental accounting still seems to be rather an unpopular outsider in accounting. To support the development towards the implementation of environmental aspects into accounting, this bachelor dissertation seeks to provide practical advice for German companies by selecting and defining a set of environmental indicators. The aim is to provide applicable and well-defined environmental indicators that address the most important global environmental issues, and that are assigned to the different value chain stages of a firm and beyond. This will be achieved, by also assigning indicators to the firm's suppliers, especially those suppliers from developing countries as they have become increasingly important to the supply chain, as well as offering corporate environmental indicators. This set of indicators will be summarized in the socalled >Environmental Tree-Model< being proposed by the author.