Biomass is key to achieve the objectives of the European Green Deal. It is defined as vegetation that forms ecosystems, sequesters carbon, and provides food and feedstocks for a wide range of biobased materials in use in sectors such as construction, energy, transport, furniture and textile industries. There is strong competition for biomass because the same type of biomass can have multiple end‑uses, including protecting it (non-use) for nature and biodiversity. The European Green Deal foresees biomass fulfilling several roles in relation to food and energy security, nature conservation, pollution reduction, and climate change mitigation and adaptation. However, scientific research indicates that not enough EU-sourced biomass will be available to fulfil all these envisaged roles in the future. This report highlights the challenges, co-benefits and trade-offs that must be understood and quantified so that biomass can help reach — and not hamper — the European Green Deal's objectives.