Researchers tested whether several “nature-based” and land-based carbon removal options can help Europe reach climate neutrality at lower cost. They added afforestation (planting new forests), perennialisation (switching annual crops to perennial systems), biochar (turning biomass into a long-lived charcoal and adding it to soils), and enhanced rock weathering (spreading crushed silicate rock so it reacts with CO2) into a detailed European energy model. The model runs at 3‑hour steps and covers 90 regions, and it co-optimises power, heat, transport, fuels and CO2 removal together.

The team used the open-source model PyPSA‑Eur and allowed the system to deploy underground CO2 storage as well as the four additional removal strategies. With these options available, the model finds a climate-neutral European system that costs about 880 billion euros per year. Adding the three chosen land-based removals lowers system cost by about 9% compared with a system without them. Afforestation, perennialisation and enhanced rock weathering are fully used in the model. Biochar was not chosen.

Together the three selected land-based options supply about 169 million tonnes of CO2 removal per year. That complements an assumed 200 million tonnes per year of underground sequestration. Those removals are large enough in the model to offset residual industrial emissions (the paper cites about 134 MtCO2/year from processes like cement) and to reduce reliance on expensive synthetic fuels for aviation and some industry uses.

A key reason biochar was not picked is competition for the same solid biomass feedstock. The model instead assigns that biomass to higher-value uses such as medium‑temperature industrial heat, combined heat-and-power plants, and biofuel production. The authors also find that a continental CO2 transport network—pipes or similar routes to move captured CO2—makes a big difference. With CO2 transport and the extra removal options, direct air capture (DAC)—a costly method that pulls CO2 straight from the air—is no longer required in the model solutions. A hydrogen transport network has a similar, smaller effect by enabling more efficient synthetic fuel production.