While crucial for policy-making and implementation, monitoring labour market trends and skills needs in the green transition can be challenging. Conventional data sources lack granularity and regional detail and are often not suitable for capturing emerging green transition skills and job profiles. This policy brief demonstrates the potential of using big data analysis of online job advertisements in the context of green transition. It presents illustrative examples of the impact of greening in sectors and occupations, and showcases how big data can be leveraged to facilitate the transition. Tracking the green transition in labour markets: using big data to identify the skills that make jobs greener