The International Maritime Organization has set a default carbon footprint value of 20.8 grams of CO2e per megajoule for Brazilian corn ethanol produced from the country's second corn crop. This is a significant step because it gives shipping companies a standardized emissions number to use when considering corn ethanol as a marine fuel. The current average fuel intensity for shipping is 93.3 grams of CO2e per megajoule, so the ethanol offers a roughly 78% reduction. Brazilian corn ethanol output has grown rapidly, reaching nearly 10 billion liters in the 2025/26 season, up from 2.65 billion liters at the start of the decade. Industry executives say the IMO definition positions corn ethanol as a viable complement to sugarcane ethanol and biodiesel for decarbonizing global shipping. One producer noted that if the entire global bunker fuel market were converted to ethanol equivalent, it would require almost 400 billion liters, meaning all sustainable biofuels will be needed.
