Brazilian sugarcane ethanol as an expandable green alternative to crude oil use

Reduction of CO2 emissions will require a transition from fossil fuels to alternative energy sources. Expansion of Brazilian sugarcane ethanol1, 2 provides one near-term scalable solution to reduce CO2 emissions from the global transport sector. In contrast to corn ethanol, the Brazilian sugarcane ethanol system may offset 86% of CO2 emissions compared to oil use, and emissions resulting from land-use change to sugarcane are paid back in just 2–8 years3, 4. But, it has been uncertain how much further expansion is possible given increasing demand for food and animal feed, climate change impacts and protection of natural ecosystems. We show that Brazilian sugarcane ethanol can provide the equivalent of 3.63–12.77 Mb d−1 of crude oil by 2045 under projected climate change while protecting forests under conservation5 and accounting for future land demand for food and animal feed production. The corresponding range of CO2 offsets is 0.55–2.0 Gigatons yr−1. This would displace 3.8–13.7% of cr...降低二氧化碳（CO₂）排放需实现从化石燃料向替代能源的转型。扩大巴西甘蔗乙醇（Brazilian sugarcane ethanol）¹,²的生产应用，可为全球交通运输行业减少二氧化碳排放提供一种近期可规模化推广的解决方案。与玉米乙醇相比，巴西甘蔗乙醇体系相较于石油使用可抵消86%的二氧化碳排放，且因将土地转为甘蔗种植所产生的排放回收期仅为2–8年³,⁴。但受粮食与动物饲料需求持续增长、气候变化影响以及自然生态系统保护等多重因素制约，其进一步扩张的可行规模始终未明确。本研究表明，在兼顾未来粮食与动物饲料生产的土地需求、保护保育林⁵的前提下，结合气候变化预测情景，至2045年巴西甘蔗乙醇可提供当量为3.63–12.77百万桶/日的原油替代量，对应的二氧化碳抵消量范围为0.55–2.0十亿吨/年。这将替代全球3.8%–13.7%的原油[原文截断]。