Biofuels are generally considered green fuels, with a zero net carbon dioxide emission.
However, according to a study published in Global Change Biology – Bioenergy in June 2012, this is not the case.
Additional greenhouse gases emissions, not considered in the standard models for biofuels emission evaluation, are associated with biofuels production.
Biofuel Energy to Prevent Climate Change
Biofuels are fuels made from biomass, such as biodiesels, which are diesels obtained from plants (i.e palm oil or sugar cane). Bioethanol is also a biofuel, and is ethanol made by the fermentation of plants or other natural sources, rather than synthesis with chemical compounds.
Green Biofuels Thought to Have a Smaller Impact on the Environment
Biofuel energy is perceived as a green alternative to the standard fossil fuels, as they are produced from renewable and natural sources. Moreover, it is believed that their impact on the environment is also smaller, as it is possible to compensate for the carbon dioxide (CO2) emissions associated with their use because the plants used for biofuel production absorb CO2; in this way the CO2 produced when they are burned is ‘offset’, leading to zero net CO2 emissions.
Climate Change: Are Biofuels Really Better?
Reports and studies published in recent years, however, started to challenge the belief that biofuel energy is a better alternative for the environment. A report published by Greenpeace in August 2011, for instance, showed that in some cases the greenhouse gases emissions from biofuels can be higher than from standard fossil fuels.
Moreover, the growth of the plants used for the biofuels production has also to be considered. A study performed by University of Oregon, published in November 2011, demonstrated that, when some forest areas were used to grow biomass, the net CO2 emissions increased in comparison with the usual forest growth.
Inclusive Study of Biomass Production and Greenhouse Gas Emissions
A detailed description of the greenhouse gases emissions associated with the production and use of biofuels was published by Prof. Timothy Searchinger, and Prof. Keith Smith, from the University of Edinburgh. The article, published in Global Change and Biology – Bioenergy, summarized the work performed by the two authors over many years. In their studies, these researchers take into account all steps in the biomass and biofuel production, and the greenhouse gases emissions associated with each of the steps.
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