Biofuels are a great classroom subject. Not only will this issue develop students' global awareness and understanding of the science of biofuels, but it can help them to develop an independent point of view on a vital issue.
Not a new phenomenon
Biofuels are nothing new. Rudolf Diesel, inventor of the diesel engine predicted the future importance of biofuels and used one in his diesel engine at the Paris World Fair in 1900. Diesel used peanut oil, but the term biofuels can refer to any organic material that can be rapidly replenished.
Introduce the topic by accessing the Guardian's Q&A section on biofuels (guardian.co.uk/environment/2008/jan/21/biofuels.alternativeenergy). Print it out, chop up into questions and answers, then challenge students to match them up. Differentiate by varying the number of questions.
Biofuels are a worldwide commodity: sugar cane and maize from the Americas; biodiesel, rapeseed and sugar beet from Europe; palm oil from south-east Asia. Provide students with a world map (eduplace.com/ss/maps/world.html) then ask them to plot the world's main biofuel producers with the help of Planet Ark (www.planetark.com/dailynewsstory.cfm/newsid/31182/story.htm), labelled with relevant facts and figures.
The UK, like other governments, is taking biofuels very seriously. The introduction of the Renewable Transport Fuel Obligation (RTFO) in April means that petrol and diesel should now contain at least 2.5% biofuel, rising to 5% by 2010. The US, with a view to reducing its dependence on other oil-producing countries, has a target of replacing 75% of oil imports with biofuel by 2025.
The world leader in biofuel motoring is Brazil, where all the cars run on ethanol or an ethanol mix. Use Brazil as a case study for students to explore. A BBC news report and video makes a good start for their investigation (http://news.bbc.co.uk/2/hi/business/4715332.stm). Ask them to produce a display or a PowerPoint presentation describing Brazil's experiences.
Show students a short film from The One Show showing how some individuals, including the footballer David James, are adopting biofuels in the UK (bbc.co.uk/theoneshow/article/2007/11/ls_biofuels.shtml). As they watch, ask students to list the different ways biofuels are being used and why people are using them, before discussing whether they think biofuels are a viable option for car users.
Biofuels are theoretically carbon neutral, as the carbon released by burning them is balanced by the carbon absorbed by plant growth. However, there is considerable alarm about the sudden rise in biofuel production, including the environmental costs of land clearance for growing biofuel crops. The overriding concern, however, is that using land normally used for food production has led to food shortages and high food prices. A recent World Bank report estimates that prices have soared by 75% - far higher than anticipated, and a rate that has forced 100 million people across the world into poverty. Challenge students to read this news report (guardian.co.uk/environment/2008/jul/03/biofuels.renewableenergy) and to translate it into a TV news report to present to the class.
Are algae the answer?
A new generation of biofuels may hold the answer. Show students an interactive presentation on the use of algae, which grows fast and is oil-rich (guardian.co.uk/environment/interactive/2008/jun/26/algae). They can research further at http://science.howstuffworks.com/algae-biodiesel.htm, before producing a cartoon strip or flowchart showing how it works.
You can sum up the study on biofuels in one of two ways. Science upd8 has an excellent lesson on biodiesel. Ask students to create a game for younger children on the pros and cons of biodiesel (upd8.org.uk/activity/256/Biodiesel.html). Alternatively, hold a trial with biofuels in the dock. Create teams for defence and prosecution, plus a jury and witnesses. The defence and prosecution must build up evidence and prepare witnesses to support their case. Is either side capable of winning, or will it leave a hung jury?