PSLifestyle Co-creating a Positive and Sustainable Lifestyle Tool with and for European Citizens No less than 72% of global greenhouse gas emissions are caused by lifestyle choices in areas such as housing, traveling, or eating*. Evidence shows that simply highlighting environmental threats does not lead to substantial behavioural change. Climate awareness at the citizen level is still not consistently translated into real action. The PSLifestyle project – Co-creating a Positive and Sustainable Lifestyle Tool with and for European Citizens aimed to close the gap between climate awareness and individual action by engaging citizens to take an active role in adopting more sustainable lifestyles. After 3.5 years of collaboration (2021–2025), the project has concluded successfully, leaving behind its flagship achievement: the Lifestyle Test. The Lifestyle Test is a free, web-based carbon footprint calculator that allows people to quickly understand their daily impact on the environment. It then inspires users to reduce their footprint through tailored lifestyle tips and actions, while also supporting them in tracking their progress. Users can build a personalised lifestyle plan, see the positive effects of their choices, and even invite friends and family to join, making sustainable change a collective effort. Since its launch, the Lifestyle Test has been taken by over 500,000 users across Europe, generating the largest European consumer dataset on sustainable lifestyles. This anonymous dataset, LifestyleData, provides insights for policymakers, businesses, civil society organisations, and academia, helping to advance sustainable lifestyles and inform evidence-based decisions across the continent. The project initially focused on eight pilot countries: Estonia, Finland, Greece, Germany, Italy, Portugal, Slovenia, and Turkey, and later expanded to Norway and Poland, with a Europe-wide version also available. Through the project’s Living Labs, citizens and decision-makers worked hand-in-hand to shape the tool. These workshops directly informed the design of the tool’s features, making it engaging, practical, and user-friendly. Beyond the Lifestyle Test, the project delivered an impressive range of outcomes: Practical guidance on running citizen science Living Labs: from ideation and workshop design to implementation and reporting. Insights into how Europeans view sustainable lifestyles and digital engagement. Policy recommendations in the form of briefs to support decision-makers. A rich collection of communication and engagement materials Within the project, CSCP had key responsibilities, including: Coordinating citizen engagement activities through Living Labs across the eight pilot countries, and acting as a local Living Lab implementer in Germany. Leading the large-scale deployment of the Lifestyle Test in Germany, generating both users and data. Coordinating engagement activities with CSOs, supporting collaboration with industry stakeholders, and implementing workshops with decision-makers across sectors. Funded under the European Union’s Horizon 2020 research program, PSLifestyle brought together a consortium of 16 partners to deliver its ambitious vision. Today, the Lifestyle Test continues as a freely accessible tool, alongside a wealth of project resources, guidance, and insights collected throughout the project. It also serves as a hub for collaboration, expansion, and further development, including tailored versions focused on biodiversity and the circular economy. For all project resources, guidance, and engagement materials, please visit: pslifestyle.eu * Hertwich and Peters, 2009