Avenues for a safe climate: Remove carbon from the atmosphere or reduce energy use?
Existing climate mitigation scenarios describe a range of potential futures, from a rapidly decreasing dependence on fossil fuels and lower global energy consumption to large-scale negative emissions that allow for the continued growth of global energy consumption. Here, we show that the difference in energy use between these two transitions has been exaggerated due to an unrealistic representation of negative emissions in existing scenarios. We find the realistic mitigation potential of negative emissions from bioenergy to be much lower than suggested in existing scenarios, with our estimates at 300 GtCO2 compared to the cross-scenario average of 650 GtCO2. Moreover, realising negative emissions at scale with alternative options may be highly energy intensive and could reduce the amount of energy available to society by more than 20%.