In the ambitious scenario, the largest reduction potential sits in energy, at 5.1 Mton CO₂-eq. It is followed by mobility at 2.5 Mton and the built environment at 2.2 Mton. This ranking shows where the largest direct climate gains toward 2030 are located.
The source does not mean that smaller domains are unimportant. Industry, agriculture and land use add further reduction, sequestration and system value. For implementation, the ranking helps set priorities: start with the largest sources and levers, while keeping the connections between sectors in view.