This Equity Band is bounded by a “Low Equity” setting on one side and a “High Equity” setting on the other. While such limits cannot be uniquely and objectively established, they are defined here in a way that captures meaningfully distinct perspectives on two hotly debated issues in climate equity. The first is the level of progressivity that is appropriate to a definition of national capacity, and the second is appropriate time frame for considering a nation’s historic responsibility. In this memo, we briefly describe how the High Equity setting and Low Equity setting (and an intermediate Medium Equity setting) are defined along these two dimensions.