Equity and energy in global solutions to climate change

• Annual energy CO2 emissions to 2050 are allocated based on a global RCP2.6 target.
• Countries are grouped according to their Human Development Index (low, medium, and high).
• Allocations are examined on the basis of fairness: equal tCO2/capita by 2050.
• Neither emissions- nor economic-based principles yield fair allocations.
• Achieving fairness requires large CO2 reductions by high HDI countries before 2050.

This paper explores the prospect for achieving an equitable allocation of country-specific carbon dioxide emissions from the energy sector within the framework of the Cancun climate stability target, as represented by Representative Concentration Pathway 2.6. Three allocation principles are considered, with the primary one (Egalitarian) based on equal per capita emissions for all countries by 2050. The two secondary allocation principles, termed Emission-based and GDP-based, distribute allowable emissions according to cumulative historical emissions and cumulative historical GDP respectively. Neither of these two allocation principles can deliver equal per capita emissions by 2050. Only when a global average constraint factor is introduced, designed to enable countries with less than allowed global average per capita emissions in any year to increase their emissions to this level, can emissions parity (the Egalitarian principle) be achieved by 2050. Finally, it is argued that achieving the widespread agreement needed to achieve climate stability is likely to be difficult, given both the size of reductions needed, especially by high-emission countries, and the inadequacies of the technical fixes proposed.