New Delhi, October 18: A United Nations report has cautioned against going all out for bio-fuels to reduce the greenhouse gas emitting hydrocarbons, saying the process of production of bio-fuels could itself be a contributor to global warming.
It says that some first generation bio-fuels such as ethanol from sugarcane can have positive impacts, and as currently practiced in Brazil, it can lead to greenhouse gas emissions reductions by between 70 per cent and well over 100 per cent when substituted for petrol, but the way bio-fuels are produced matters in determining whether they are leading to more or less GHG emissions.
The report ‘Towards Sustainable Production and Use of Resources: Assessing Biofuels’ is based on a detailed review of published research up to mid-2009 as well as the input of independent experts world-wide.
It has been written to assist governments and industries in making sustainable choices in an area that over the past few years has become deeply divided while triggering sharply polarised views.
The report makes it clear that bio-fuels have a future role, but also underlines that there may be other options for combating climate change, improving rural livelihoods and achieving sustainable development that may, or may not involve turning ever more crops and crop wastes into liquid fuels. For example, it says, generating electricity at local power stations using wood, straw, seed oils and other crops or waste materials “is generally more energy efficient than converting biomass into liquid fuels”.
Land, including abandoned land, can be used for energy crops but could equally be used for re-afforestation or solar power which the report argues may be more efficient for converting sunlight into energy.
Meanwhile, in transport, modal shifts and higher fuel efficiency standards and the development of alternative technologies such as plug-in vehicles could dramatically reduce emissions in their own right.
The report points out that in the United States the Energy Independence Act requires fuel efficiency improvement of 40 per cent for cars and light trucks by 2020. Similarly, Japan is set to adopt a 20 per cent fuel efficiency improvement to be implemented by 2015 with car makers there claiming that 80 per cent of vehicles already meet the proposed standard.
There are also wider life cycle issues that need to be factored into government policy decisions and in some cases these require more urgent research.
Growing energy crops can involve increased use of fertilisers which in turn have implications for water quality. Fertiliser use also increases emissions of N20, which is a powerful greenhouse gas in its own right.
—Agencies