Ethanol is made by fermenting plant sugars or the by-products of petroleum processing. Traditionally used as both an alcohol and a fuel for heat and light, today ethanol is employed as a transport fuel.

Because it can be derived from renewable resources such as plant matter and organic waste, ethanol can replace the fossil fuels commonly used for transport fuel. Fossil fuels are one of the leading contributors to climate change, so biofuels such as ethanol could reduce human dependency on traditional high-emission fuels.

About 5% of ethanol is produced from petroleum products, however the large majority is derived from plant material. Traditionally ethanol has been made from sugar cane, sorghum, barley, hemp, potatoes, cassava, sunflower, fruit, molasses, corn, grain, wheat, straw and cotton plants.

Unfortunately, most of these plants are also important sources of food for human consumption.

Biofuels have a bad name in global humanitarian debates. Oxfam reports that biofuels such as ethanol pushed 30 million extra people into poverty in 2008 as a result of competition between using crops for food or fuel. Their report suggests that the 2007-2008 global food crisis was 30% due to rising food prices that resulted from converting crops into ethanol.

The ‘food versus fuel’ debate means that ethanol shares many of the same public relations problems as biochar, as both fuels require agricultural land or forests that currently support human and animal life.

Despite these significant concerns with the current production of ethanol, new research into offers some solutions.

New ‘cellulosic ethanol’ is less expensive and more energy-efficient than traditional ethanol. Even better, cellulosic ethanol can be made from everything from sawdust to waste paper, grasses, and crop wastes. One of the main benefits of this new technology is that cellulose is not needed for human food.

Perennial grasses and fast-growing woody crops are promising sources of cellulosic ethanol. Yet these quick-growing non-food crops still pose problems because of the rapid rate at which they degrade the soil.

Clearly ethanol poses problems as well as opportunities. More research into soil-friendly technology and greater fuel efficiency are also needed before ethanol can have a prominent role as a solution to climate change.


Dr Paul Willis, ‘The Ethanol Alternative’, 12 October 2006, Catalyst,

Environmental Protection Authority, ‘U.S. Greenhouse Gas Inventory’, 1 December 2009,

Dr. Christoph Berg, ‘World Fuel Ethanol: Analysis and Outlook’, Japanese Ministry of Economy, Trade and Industry,

University of Minnesota’s Institute on the Environment, ‘Biofuels Debate’, 8 August 2008,

Oxfam International, ‘Another Inconvenient Truth’, June 2008,

Kevin Bullis, ‘Will Cellulosic Ethanol Take Off?’, Technology Review, 26 February 2007,

Alice Friedemann, ‘Peak Soil: Why cellulosic ethanol, biofuels are unsustainable and a threat to America’, Culture Change, 11 April 2007,