The green arrow represents the demand-side emissions reductions potentials. The range in potential is shown by a line connecting dots displaying 
the highest and the lowest potentials reported in the literature. Food shows demand-side potential of socio-cultural factors and infrastructure use, and changes in land-use patterns 
enabled by change in food demand. Demand-side measures and new ways of end-use service provision can reduce global GHG emissions in end-use sectors (buildings, land transport, 
food) by 40–70% by 2050 compared to baseline scenarios, while some regions and socioeconomic groups require additional energy and resources. The last row shows how demand-
side mitigation options in other sectors can inﬂuence overall electricity demand. The dark grey bar shows the projected increase in electricity demand above the 2050 baseline due 
to increasing electriﬁcation in the other sectors. Based on a bottom-up assessment, this projected increase in electricity demand can be avoided through demand-side mitigation 
options in the domains of infrastructure use and socio-cultural factors that inﬂuence electricity usage in industry, land transport, and buildings (green arrow). {WGII Figure SPM.4, 
WGII Cross-Chapter Box FEASIB in Chapter 18; WGIII SPM C.10, WGIII 12.2.1, WGIII 12.2.2, WGIII Figure SPM.6, WGIII Figure SPM.7}
4.5.1. Energy Systems
Rapid and deep reductions in GHG emissions require major 
energy system transitions (high conﬁdence). Adaptation options 
can help reduce climate-related risks to the energy system 
(very high conﬁdence). Net zero CO2 energy systems entail: a 
substantial reduction in overall fossil fuel use, minimal use of 
unabated fossil fuels153, and use of Carbon Capture and Storage in 
the remaining fossil fuel systems; electricity systems that emit no 
net CO2; widespread electrification; alternative energy carriers in 
applications less amenable to electrification; energy conservation 
and efficiency; and greater integration across the energy system 
(high confidence).