By Barbara Nwaiwu
An analysis of 103 European cities’ climate-neutral plans shows that municipalities are planning to rely on carbon removal to compensate for about a fifth of their emissions by 2030, which would require removing roughly 61 million tonnes of emissions from the atmosphere, which is close to Austria’s annual emissions.
The study, published on Friday, in Nature Climate Change, was led by the Joint Research Centre of the European Commission and contributed to by scientists at the Potsdam Institute for Climate Impact Research (PIK). The analysis included 22 European capital cities.
The study found that the majority of the cities’ residual emissions are expected to come from the energy and transport sectors, with median shares of 50% and 31% respectively, despite both sectors being considered relatively easy to abate.
The authors said the findings raised concerns about the effectiveness of the cities’ strategies, the constraints faced by urban areas and the strict timelines for achieving climate neutrality, warning that the cost and speed of action could be prioritised over more transformative changes.
“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 have not given enough consideration to options that would eliminate these emissions in the first place,” commented PIK scientist and co-author of the study, Quirina Rodriguez Mendez.
The study developed the Residual Emission Strategies Robustness Index (RESRI) to assess the strength of cities’ strategies to dealing with emissions that remain after reduction measures. The index points to weaknesses in monitoring and quantifying how much carbon dioxide removal would be available to cities and when.
Current estimates of carbon removal capacity cover only 18% of the total residual emissions identified in the cities’ plans.
“It’s really important that these removals actually happen and are transparently accounted for so that bad practice doesn’t reduce them to mere hot air,” Rodriguez Mendez said.
The study recommends that cities frontload emissions reductions and ensure that residual emissions are concentrated mainly in hard-to-abate sectors. It also suggests demand-side measures, which could reduce emissions by between 40 and 80%, depending on the context.
The analysis found that the 103 cities overwhelmingly plan to rely on land-based carbon removals, including tree planting. The researchers raised concerns about the permanence of such removals and the availability of land in urban areas, where space is also needed for housing, health and energy.
The study noted that the climate-neutral plans did not include detailed assessments of land availability, creating uncertainty over whether the planned land-based removals could be delivered.
Permanent carbon removal was less prominent in the cities’ plans, with 32% mentioning it. Bioenergy with carbon capture and storage featured in 27% of plans, biochar in 13% and direct air carbon capture and storage in 7%.
Carbon credits featured in 40% of the plans but were often poorly specified, used as a last resort and met with widespread distrust by the cities themselves.
The study suggests that cities seeking to achieve and maintain climate neutrality may need to gradually complement temporary carbon dioxide removal with more permanent options.
However, the researchers said this would require regulatory clarity, infrastructure development and predictable support, particularly for permanent carbon removals, with national and international governance bodies needing to work together to support their development.
