Drivers of stagnating global carbon intensity of electricity and the way forward

Highlights: • Global aggregate carbon intensity (ACI) of electricity has stagnated since 1990. • ACI is decomposed over 5 time periods to identify key factors driving this stagnation. • The contribution of countries and energy sources to these factors is also quantified. • Greater penetration of renewables is needed to offset the geographical shift effect. - Abstract: Despite the signing of the Paris climate agreement, there is still great uncertainty regarding the world's ability to decarbonize and meet the 2 °C target. In this regard, the electricity production sector deserves particular attention. The sector has the largest decarbonization potential and its share of the world's CO₂ emissions from fuel combustion increased from 30% in 1990 to 36% in 2014. To better understand global trends, this study analyses the factors influencing changes in the global aggregate carbon intensity (ACI) of electricity, a measure of the level of CO₂ emissions per unit of electricity produced, over the last 25 years using multidimensional index decomposition analysis. It finds that global ACI barely improved since 1990 because of a shift in electricity production from developed to developing countries with higher ACIs. This geographical shift offset consistent improvements to power generation efficiency worldwide and is likely to persist in the future. To keep the 2 °C target realisable, it is imperative to enhance international cooperation to lower the ACIs of emerging economies and deepen the penetration of renewables, which have thus far performed below expectations.