Abandoned sugarcane plantations across the tropics could offer us a realistic, sustainable alternative to fossil fuels – according to new research published in Nature Climate Change this week.
Ethanol produced from sugarcane has been one of the most successful short-term strategies to date in decarbonizing energy supply, particularly in Brazil where the sugarcane ethanol system results in just 14% of the CO2 emissions of petroleum. In 2012 Brazil became the first country in which more bioethanol was used in cars than petroleum.
Scaling up global production would help meet international commitments made as part of the Paris Agreement on Climate Action to reduce CO2 emissions to prevent global temperatures rising more than two degrees Centigrade.
However, researchers weren’t clear if it would be possible to expand - or even maintain – sugarcane production given increasing global demand for food and animal feed, climate change impacts and the need to protect natural ecosystems such as the Amazon.
But new projections published this week in their paper ‘Brazilian sugarcane ethanol as an expandable green alternative to crude oil use’ show it could be possible.
Using state-of-the-art mechanistic models of crop productivity, projections of future food demand, techno-economic development and climate change, researchers projected that in Brazil alone sugarcane ethanol could provide between 3.8 and 13.7% of current global crude oil consumption by 2045, offsetting up to 5.6% - or two Gigatons - of net emissions.
Emissions caused by converting land to sugarcane could also be paid back within just 5 years.
The research group from Brazil, Europe and the USA, was led by University of Illinois and Lancaster University Crop Sciences Professor, Steve Long.
Professor Long said: “Reducing emissions is a problem that will require multiple solutions. However, this is technology that is here and demonstrated. It is readily expandable and useable on the large areas of land across the tropics from Hawaii and Australia to the Caribbean that were once covered with sugarcane and now lie abandoned.
"This study shows that it is theoretically possible to develop production of sugarcane ethanol as an alternative to fossil fuels as one part of the solution to our commitment to cut carbon emissions. The land and potential is there to build upon existing success in Brazil and, compared to other options, a technology-ready step toward achieving the mitigation goals set by COP21.”