Carbon dioxide can be removed from the atmosphere by natural or technical means. Natural sinks such as bogs can be restored and innovative technologies already exist to capture carbon from the air. Researchers in the "Netto-Zero-2050" cluster of the Helmholtz Climate Initiative have identified the most promising approaches in Germany. They show that natural sinks can be scaled up in the short term, while technologically advanced approaches could only reduce greenhouse gases in the medium term and carry potential risks. (Meike Lohkamp)