Sustainable biofuels are crucial for decarbonizing the transport sector, offering significant potential to reduce emissions in aviation and shipping while complementing electric vehicles and energy efficiency in road transport. However, the large-scale deployment of biofuels brings challenges. The climate benefits of biofuels depend on their carbon intensity, highlighting the need for sound regulatory frameworks and transparent, science-based calculations to attract investment. A recent study for Brazil’s G20 presidency explores the complexities of biofuel carbon intensity across regions and emphasizes the need for policies that encourage continuous improvement in sustainable biofuel practices.