Residual Emissions Requiring Carbon Removal

Even with aggressive decarbonization, cities face residual emissions from waste incineration, industrial processes, and hard-to-abate sectors that cannot be eliminated by 2030–2040 deadlines. Reaching net-zero therefore requires negative emission technologies — carbon capture at point sources, direct air capture, or carbon mineralization — that are expensive, unproven at scale, and carry the risk of becoming an excuse to delay emission reductions.