The value of BECCS with overshoot targets (top) and ceiling targets (bottom)
Figure 2. The value of BECCS with overshoot targets (top) and ceiling targets (bottom). Abatement costs in per cent of discounted future GDP as a function of temperature target for multiple model runs. Cases shown are: no CCS with overshoot targets (dark red), fossil CCS with overshoot targets (dark blue), fossil CCS and BECCS with overshoot targets (dark green), no CCS with ceiling targets (light red), fossil CCS with ceiling targets (light blue) and fossil CCS and BECCS with ceiling targets (light green).
In order to meet stringent temperature targets, active removal of CO2 from the atmosphere may be required in the long run. Such negative emissions can be materialized when well-performing bioenergy systems are combined with carbon capture and storage (BECCS). Here, we develop an integrated global energy system and climate model to evaluate the role of BECCS in reaching ambitious temperature targets. We present emission, concentration and temperature pathways towards 1.5 and 2 ° C targets. Our model results demonstrate that BECCS makes it feasible to reach temperature targets that are otherwise out of reach, provided that a temporary overshoot of the target is accepted. Additionally, stringent temperature targets can be met at considerably lower cost if BECCS is available. However, the economic benefit of BECCS nearly vanishes if an overshoot of the temperature target is not allowed. Finally, the least-cost emission pathway over the next 50 years towards a 1.5 ° C overshoot target with BECCS is almost identical to a pathway leading to a 2 ° C ceiling target.