Synergies with mitigation are identiﬁed as high, medium, and low. The right-hand side of panel (a) provides an overview of selected 
mitigation options and their estimated costs and potentials in 2030. Relative potentials and costs will vary by place, context and time and in the longer term compared to 2030. Costs 
are net lifetime discounted monetary costs of avoided greenhouse gas emissions calculated relative to a reference technology. The potential (horizontal axis) is the quantity of net 
GHG emission reduction that can be achieved by a given mitigation option relative to a speciﬁed emission baseline. Net GHG emission reductions are the sum of reduced emissions 
and/or enhanced sinks. The baseline used consists of current policy (around 2019) reference scenarios from the AR6 scenarios database (25–75 percentile values). The mitigation 
potentials are assessed independently for each option and are not necessarily additive. Health system mitigation options are included mostly in settlement and infrastructure 
(e.g., efﬁcient healthcare buildings) and cannot be identiﬁed separately. Fuel switching in industry refers to switching to electricity, hydrogen, bioenergy and natural gas. The length 
of the solid bars represents the mitigation potential of an option. Potentials are broken down into cost categories, indicated by different colours (see legend). Only discounted lifetime 
monetary costs are considered. Where a gradual colour transition is shown, the breakdown of the potential into cost categories is not well known or depends heavily on factors such 
as geographical location, resource availability, and regional circumstances, and the colours indicate the range of estimates. The uncertainty in the total potential is typically 25–50%. 
When interpreting this ﬁgure, the following should be taken into account: (1) The mitigation potential is uncertain, as it will depend on the reference technology (and emissions) 
being displaced, the rate of new technology adoption, and several other factors; (2) Different options have different feasibilities beyond the cost aspects, which are not reﬂected in 
the ﬁgure; and (3) Costs for accommodating the integration of variable renewable energy sources in electricity systems are expected to be modest until 2030, and are not included.