Drawing upon the ambitious policy and legal framework outlined in the European Strategy for Data (2020) and the establishment of common European data spaces, this Science for Policy report explores innovative approaches for unlocking relevant data to achieve the objectives of the European Green Deal. The report focuses on the governance and sharing of Green Deal data, analysing a variety of topics related to the implementation of new regulatory instruments (i.e. the Data Governance Act and the Data Act) as well as the roles of various actors in the data ecosystem. It provides an overview of current incentives and disincentives for data sharing, and explores the existing landscape of data intermediaries and data altruism organisations. Additionally, it offers insights from a private sector perspective and outlines key data governance and sharing practices concerning citizen-generated data (CGD). Lastly, it provides a series of policy recommendations to support the ongoing revision of the INSPIRE Directive (2007), within the context of the common European Green Deal data space, and toward a more sustainable and fair data ecosystem.