 In this video we are going to review the social, economic and environmental effects of biofuels. You will find it useful to have studied the videos carbon footprints and carbon neutral and biofuels before continuing with this video. Biofuels come from living organisms. These could include biodiesel made from certain vegetables or the methane biogas made by decaying manure or sewage. Finally, another example of a biofuel is bioethanol, obtained from plant materials and used as a fuel. Whilst in principle using living matter to create fuel for energy sounds a good one, there are both negative and positive aspects. From a societal point of view, biofuels can be seen as good or bad, depending on where you are. In addition, the social issues of biofuels are often related to the economic ones. One advantage of biofuels is that they have caused oil prices to stabilise. It is estimated that without the development of these fuels as an alternative to oil, that petrol prices could be up to 25% more expensive in the future. And so just by beginning biofuel development and production it is relieving pressure on the consumer. The one thing this gives us is time. Time to develop and evaluate the uses of biofuels as a potential energy alternative. Researchers at the Overseas Development Institute have argued that biofuels could help to reduce poverty in the developing world, for increased employment and by stabilising petrol oil prices, as many developing countries are net importers of oil. However, the sustained use of biofuels is a complex issue, and its transport, the duties paid on it, will affect economies of many developing nations. Therefore, careful consideration has to be given to have worldwide regulation, and whether each nation should or should not produce biofuels. The biggest social problem is that biodiesel and biophenol comes from plants. Can you think how we generally use plants and where they are grown? This will help you see the problem. Pause the video, think about this and continue when you are ready. If you suggested that most of the plants that we grow, or crops, are our food supply, you've probably identified the key issue. Crops require vast areas of fertile or arable land. If more of this is used to grow plants or biofuels, then there is less arable land available for growing food. For this reason, the production of biofuels could contribute to the global food shortage. This is often referred to as the food versus fuel debate, and is one that needs serious consideration. An economic point is that modifications are necessary to run internal combustion engines and biofuels, and two depends on the type of biofuel used and the engine type. For example, whilst petrol engines can be run on biophenol without any modifications, minor modifications are required for them to run on biophenol or biomethanol, and this would be costly. Similarly, other modifications are needed for diesel cars so that they are able to run on biodiesel. So if you've just bought a petrol or diesel car, would you be willing to do this? The environmental effects of biofuels are also linked to the social effects. In order to gain land to grow crops suitable for biofuel production, massive deforestation has to take place. To understand the issue, think about what key process trees do, and why it isn't beneficial to the environment to have mass deforestation for land space. Pause the video, think about these questions, and continue when you're ready. The answer is that trees remove carbon dioxide from the atmosphere by photosynthesis and produce oxygen. Removing trees to make space for biofuel crops contributes directly to global warming by allowing greenhouse gas emissions to increase. In addition, the soil used to grow crops will become depleted of nutrients over time, as growing crops and deforested land accelerates this process. There are four main bioefenol crops, corn, sugarcane, sweet sorghum, and pine, which are hugely farmed. Increasing their production to meet energy demands means that fresh water supplies could also be depleted, reducing the amount of fresh water available for drinking. Finally, you may have heard that biofuels are carbon neutral, but the process for calculating the amount of carbon dioxide released by burning and the amount absorbed when the plant is growing is a complex and inexact science, as yet carbon neutrality remains a controversial point. In summary, whether or not biofuels are carbon neutral is controversial and needs more research before we can decide if it is a real environmental benefit.