Several European cities have plans to achieve climate neutrality by 2030, but the focus of these efforts may be skewed toward less prioritized dimensions that will make true decarbonization more difficult.
Researchers from the Joint Research Centre (of the European Commission) and the Potsdam Institute for Climate Impact Research (PIK) analyzed the climate action plans of 103 European cities, including 22 capitals, whose primary goal is carbon neutrality by the end of the decade.
One of the challenges to reaching that goal are residual emissions, those that persist after all viable reduction solutions—from an economic, social and technical standpoint—have been implemented.
To respond to this challenge, all municipal strategies contemplate approaches for temporary removal of carbon dioxide (CO2) through soils and plants, such as tree planting and soils as carbon sinks.
Researchers say that the reliance on these approaches raises concerns about the permanence and availability of land in urban spaces, where, they note, the area available for green spaces that would enable this type of solution competes with other sectors, such as housing.
Published in the journal Nature Climate Change, the study also reveals that around 40% of municipalities look to carbon credits as the solution and 32% consider permanent removal approaches, such as bioenergy with carbon capture, biochar and decentralized carbon capture and storage solutions.
The researchers say that the plans tend to be imprecise and lacking in detail regarding the viability and mode of implementation of the decarbonization solutions they present, which can lead to effectiveness deficits, potentially even calling into question the targets assumed.
“These cities are pursuing extremely ambitious decarbonization targets, which should be applauded and should serve as inspiration for others,” says Quirina Rodriguez Mendez, a researcher at PIK and co-author of the study.
However, she warns that “they are using vague criteria to determine where residual emissions will come from and may not have properly considered options that would eliminate precisely these emissions.”
The team of scientists estimates that the majority of residual emissions in the European cities covered by this study will come from the energy and transport sectors, although they are considered easily reducible.
Therefore, they say that municipal leaders should focus residual emissions in sectors where decarbonization is truly challenging, and they also say that demand-side measures (from consumers and residents) should be implemented, which could allow reductions in residual emissions between 40% and 80%.
All things considered, the researchers believe that achieving and maintaining carbon neutrality may require cities to complement temporary CO2 removal approaches with more permanent solutions. But for this to happen, regulatory clarity is needed, infrastructure developed and public support guaranteed, especially regarding permanent carbon removals.
