Getting the sums right
Biofuels researcher Angela Karp explains:
'You need to look at the whole life cycle. Sowing seeds, harvesting crops and processing them into biofuels all require energy. Much of this energy comes from carbon-belching fossil fuels - like using diesel in tractor engines, or burning coal for electricity.'
One British study found that making each tonne of bio-diesel from oil-seed rape releases around 900 kg of CO2 in these 'hidden emissions'.
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| A biofuel's true carbon footprint includes its production. |
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