Table 1.

Symbols for environmental impacts and the actors and forces that affect them, exemplified by energy emission

Category	Symbol	Actors	Dimension
Impact	I	All	Emission
Population	P	Parents	Capita
Affluence	A	Workers	GDP/capita
Intensity of use	C	Consumers	Energy/GDP
Efficiency	T	Producers	Emission/energy
Consumption/capita	A × C		Energy/capita
Consumer challenge	P × A × T		GDP × (Emission/Energy)
Technology challenge	P × A × C		Energy
Sustainability challenge	P × A		GDP
Sustainability levers	C × T		Emission/GDP