More than 100 European cities have pledged to reach climate neutrality by 2030, and a new study shows they plan to lean on carbon removal to close roughly a fifth of their remaining emissions. The catch: the removal capacity those plans can actually point to covers only 18% of what would be needed. The study in Nature Climate Change, led by the European Commission’s Joint Research Centre with scientists from the Potsdam Institute for Climate Impact Research (PIK), is the most detailed reading yet of how municipalities intend to handle residual emissions. For carbon removal developers and credit suppliers, it is both a demand signal and a warning.
What the Study Found
The analysis covers 103 cities, including 22 capitals, whose 2030 climate neutrality plans have been formally assessed. Across those plans, total residual emissions at the target date amount to 61.4 million tonnes of CO2 equivalent, a volume roughly comparable to Austria’s annual emissions. Cities intend to compensate for that remainder largely through removals rather than further cuts.
The composition of the residuals is uncomfortable reading. Median shares attribute 50% of residual emissions to energy and 31% to transport, the two sectors generally considered the easiest to decarbonise with technologies that already exist. That suggests many plans are treating removals not as a last resort for genuinely hard-to-abate activity, but as a substitute for reductions that could plausibly be delivered within the same decade.
The authors put numbers on the credibility gap. They built a Residual Emission Strategy Robustness Index to score how well each plan defines, quantifies and schedules its removals. The headline result: current estimates of removal capacity available to the cities cover only 18% of the residual emissions identified in the plans.
A Land-Based Bet With Permanence Problems
The cities’ removal strategies lean overwhelmingly on land-based approaches such as tree planting. That choice carries two structural risks the study flags directly. First, permanence: biological storage can be reversed by fire, disease or land-use change. Second, land itself: urban space is contested by housing, health and energy needs, and the plans include no detailed assessments of land availability for the removals they assume.
Durable removal options barely feature. Only 32% of plans mention permanent carbon removal at all. Bioenergy with carbon capture and storage appears in 27% of plans, biochar in 13% and direct air capture with storage in just 7%. In other words, the segment of the removal market with the strongest permanence credentials is largely absent from the documents that are supposed to drive municipal demand.
Cities Want Removals but Distrust Credits
Carbon credits appear in 40% of the plans, but the study describes them as poorly specified and typically positioned as a last resort. It also notes widespread distrust of credits among the cities themselves. That is a striking posture for a buyer group: municipalities expect to compensate for a fifth of their emissions, yet they are reluctant to use the instrument specifically designed to finance removals beyond their boundaries.
“These cities are pursuing extremely ambitious decarbonisation targets, which is to be applauded and should serve as an inspiration to others. But they are using vague criteria to determine where residual emissions will come from, and might not have given enough consideration to options that would eliminate these emissions in the first place,” said Quirina Rodriguez Mendez, a scientist at PIK and co-author of the study. She added that removals must actually happen and be transparently accounted for, so that bad practice does not reduce them to “mere hot air.”
The study’s recommendations cut in two directions. Cities should bring forward emissions reductions and restrict residuals to sectors that are genuinely difficult to decarbonise, and they should adopt demand-side measures, which the authors estimate could reduce emissions by 40% to 80% depending on the context. Both recommendations shrink the removal requirement before any tonne is procured.
What It Means for Developers and Buyers
For removal developers, the study maps a demand pool of 61.4 MtCO2e that is currently anchored to the least durable supply category. The commercial opening is in converting municipal plans from unspecified land-based assumptions to contracted durable removals, but the study’s own numbers show how far the market has to go: an 18% coverage rate means most of the demand has no identified supply behind it at all.
For credit suppliers and standards bodies, the municipal distrust is the variable to fix, not to lament. Cities avoiding credits because they are poorly specified is a product problem. Procurement frameworks with clear permanence thresholds, transparent accounting and corresponding-adjustment style safeguards would directly address the objections the study records. First movers that design for public-sector procurement rules will face a buyer group that, by its own plans, must source removals somewhere.
What to Watch
Three markers will show whether the gap closes. First, whether cities revise plans to cut residuals in energy and transport, which would shrink the 61.4 Mt figure before procurement begins. Second, whether the share of plans naming durable removals rises above the current 32%, and whether BECCS, biochar and DACCS move from mentions to contracted volumes. Third, whether any city or city network publishes removal procurement criteria: the moment a municipality writes permanence and accounting standards into a tender, the voluntary market gains a reference buyer it has so far lacked.
