Enabling Full Supply Chain Corporate Responsibility: Scope 3 Emissions Targets for Ambitious Climate Change Mitigation

There is building consensus that nonstate actors have
the potential
to drive more ambitious action toward climate targets than governments,
thus driving the necessary transition to ensure that humanity remains
within a safe operating space. These bottom-up mitigation activities,
however, require individual targets on both direct and indirect (upstream)
greenhouse gas (GHG) emissions in order to reconcile trade-offs between
global and local sustainability goals. Here we use a scenario-driven
approach based on a global multiregional input–output (GMRIO)
model to develop scope 3 emission reduction targets for individual
economic sectors, comparable across countries and geographies. Under
an ambitious carbon mitigation scenario for 2035 (that follows a trajectory
of 1.75 °C total warming by 2100), global upstream scope 3 emission
intensities need to be reduced by an additional 54% compared to a
baseline scenario with reference technology. On a sectoral basis,
this is equivalent to a 58–67% reduction in energy, transport,
and materials, a 50–52% reduction in manufacturing, services,
and buildings, and a 39% reduction in agriculture, forestry, and other
land use. By aligning indirect supply chain targets with ambitious
carbon mitigation scenarios, our approach can be used by nonstate
actors to set actionable scope 3 targets and to build climate-compatible
business models.