SAF stands for Sustainable Aviation Fuel. It is a type of aviation fuel made from renewable sources such as used cooking oil, agricultural waste, animal fats, or even household garbage. Unlike traditional jet fuel which comes from crude oil, SAF reduces carbon dioxide emissions by up to 80% over its lifecycle. SAF can be blended with conventional jet fuel and used in existing aircraft engines without modification. Currently, most aircraft can operate with a blend of up to 50% SAF. Airlines are increasingly using SAF to reduce environmental impact and meet international climate goals. The main challenges are limited supply and higher cost. SAF即可持续航空燃油，由废餐饮油、农业废弃物、动物脂肪、生活垃圾等可再生原料制成。与传统原油基航油不同，SAF 全生命周期可减碳最高 80%，可与常规航油混合，无需改装即可用于现役发动机。目前多数飞机可使用最高 50% 比例的 SAF 混合油。航空公司广泛使用 SAF 以降低环境影响、实现气候目标。主要挑战是供应有限、成本较高。

SAF has several advantages over traditional jet fuel. First, it significantly reduces carbon dioxide emissions by up to 80% over its lifecycle, helping aviation fight climate change. Second, SAF produces fewer particulates and sulfur oxides, resulting in cleaner engine exhaust and improved local air quality around airports. Third, SAF can be blended with conventional fuel and used in existing aircraft engines without modifications. Fourth, it is compatible with current refueling infrastructure. Fifth, using waste materials promotes circular economy. The main issues are higher cost and limited supply. SAF相较传统航油优势明显：全生命周期减碳最高 80%，助力应对气候变化；颗粒物与硫氧化物排放更低，机场周边空气质量更好；可直接掺混使用，无需改装发动机与加油设施；兼容现有储运系统；使用废弃物原料有利于循环经济。当前主要问题是成本更高、供应有限。

The main challenges of SAF are cost and supply. SAF is currently two to four times more expensive than traditional jet fuel. Production capacity is limited with few refineries worldwide. Feedstock availability is also a challenge – collecting enough used cooking oil or agricultural waste is difficult at scale. Certification and testing take time. Blending limits are up to 50% now, while 100% SAF is under test. Transportation and storage need careful management to avoid contamination. Investment and technology are improving quickly. SAF主要挑战是成本与供应：价格是传统航油的 2-4 倍；全球炼厂少，产能有限；原料收集难度大；认证与测试周期长；目前多数发动机最大掺混比例 50%，纯 SAF 仍在试验；运输与储存需严格管理防污染。相关投资与技术正在快速进步。

SAF plays a critical role in aviation's net-zero emission target. IATA has committed to net-zero by 2050, and SAF is expected to contribute about 65% of emission reductions. Unlike electric or hydrogen aircraft needing new designs, SAF can be used in today's fleet without modifications, making it the most immediate solution. Achieving net-zero needs massive investment: SAF will rise from ~1% now to over 60% by 2050. Governments and airlines are expanding refineries, lowering costs, and increasing feedstock supply. SAF is the most important solution for decarbonization. SAF是航空业实现净零排放的核心方案。IATA 承诺 2050 年净零碳排放，SAF 预计贡献约 65% 减排量。与需全新设计的电动 / 氢能飞机不同，SAF 可直接用于现有机队，是最即时可行的方案。实现净零需要大规模投资：SAF 占比将从目前约 1% 提升至 2050 年的 60% 以上。各国与航空公司正扩建炼厂、降低成本、增加原料供应。SAF 是航空脱碳最重要的解决方案。