With this briefing we provide definitions for units and metrics commonly used in climate and energy modelling. We provide this briefing, because in climate and energy system modelling,the same data can be represented using a diverse set of units and metrics. This leads to challenges when it comes to comparability and re-use. Only when we are certain that a variable is measured in a specific unit or metric, we can use it without the chance of producing errors. For example we may want to compare results of different projections with each other or apply a specific variable in our own modelling work. Sometimes, a conversion is needed which may not be straight forward. We cover units in Section 3, greenhouse gases in Section 4, monetary values in Section 5 and geographic coordinates in Section 6. Throughout these sections, we provide – where available – links to conversion tables hosted on the Open Energy Platform. Like this, we combine what we learn below with practical and open access tools for everyday work. This briefing may develop further and is open to suggested additions by anyone. Please post suggestions on github. Please attach the label conversion-briefing to your issue.

This work was supported by grant 03ET4057A–D (SzenarienDB) from the Federal Ministry for Economic Affairs and Energy of Germany (BMWi).