6.6B - Biofuels
Biofuels are an alternative energy source that are increasing globally; growth in biofuels however has implications for food supply as well as uncertainty over how 'carbon neutral' they are. (Biofuels in Brazil)
Of all the energy sources used by humans, fuelwood perhaps has the longest history. However, while fuelwood remains important in the energy mix of some parts of the world, biomass has recently come into prominence with the commercial use of a number of relatively new biofuels. This is organic matter used as a fuel, for example in power stations for the generation of electricity.
The growing of biofuel crops is being increasingly recognised as one way of reducing both the burning of fossil fuels and carbon dioxide emisions. The most widely grown biofuel crops include wheat, maize, grasses, soy beans and sugar cane. In the UK, the two main crops are oilseed rape and sugar beet. Most of these two crops are converted into ethanol or biodiesel, which are mainly used as a vehicle fuel.
The downside: each hectare of farmland used to grow energy crops means a hectare less for growing much-needed food in an increasingly hungry world. They are supposedly carbon neutral, since the carbon dioxide they produce when burnt, is only that they took from the environment whilst growing, but there is uncertainty over how carbon neutral they actually are. (Since what was on the land before them, e.g. a forest, is destroyed.)
Biofuels in Brazil
Since the 1970s, Brazil has taken steps to diversify its energy mix and improve its energy security. This drive has been spearheaded by developing the country's considerable hydropower resources. More recently, it has added biofuels to its energy mix. Although less than 5% of Brazil's energy comes from renewable energy sources, 90% of new passenger vehicles sold in the country have flex-fuel engines that work using any combination of petrol and ethanol. This has led to a significant reduction in the country's carbon emissions.
Large areas of central southern Brazil are now set aside for the cultivation of sugar cane and the subsequent production of ethanol. The result has been the displacement of other types of agriculture, particularly cattle rearing. The need to find replacement pastures has led to large-scale clearance of tropical rainforest in the Amazon Basin. This deforestation nullifies the reduction in carbon dioxide emissions gained from the increasing use of ethanol.
Large areas of central southern Brazil are now set aside for the cultivation of sugar cane and the subsequent production of ethanol. The result has been the displacement of other types of agriculture, particularly cattle rearing. The need to find replacement pastures has led to large-scale clearance of tropical rainforest in the Amazon Basin. This deforestation nullifies the reduction in carbon dioxide emissions gained from the increasing use of ethanol.