In the course of growing concerns about unstable oil supplies and the impact of fossil fuels on global warming, bio fuels are receiving increased attention. Putting ethanol instead of gasoline in your tank saves oil and is probably no worse for the environment than burning gasoline. 

Bio fuels, which are made from corn, palm oil, sugar cane and other agricultural products, have been seen by many as a cleaner and cheaper way to meet the world's soaring energy needs than with greenhouse-gas emitting fossil fuels. Ethanol is considered as major bio fuel.
 
Ethanol is an alcohol-based fuel made by fermenting and distilling crops that have been broken down into simple sugars. Ethanol can be used as a fuel for non-diesel engines (spark ignition) or as an additive to gasoline engines In the U.S., ethanol is mostly manufactured from starchy crops like corn.

There are two types of ethanol fuel that are commonly referred to- e85 and e10. E85 is a blend of 85 percent ethanol and 15 percent gasoline that’s used in flex-fuel vehicles. E10 is a gasoline blend that contains up to 10 percent ethanol.

Brazil, which produces large amounts of ethanol, uses sugar cane to manufacture the fuel. Brazil is the largest producer and consumer of ethanol in the world and has a goal of having all of its vehicles capable of running on ethanol or gasoline, in the next few years. Countries like Brazil have made ethanol a viable alternative energy fuel because they have devoted time to research and government funding.

“Replacing only five percent of the nation’s diesel consumption with biodiesel would require diverting approximately 60 percent of today’s soy crops to biodiesel production,” says Matthew Brown, an energy consultant and former energy program director at the National Conference of State Legislatures. 

European leaders have decided that at least 10 percent of fuels will come from bio fuels, like ethanol, by 2020, and the U.S. Congress is working on a proposal that would increase production of bio fuels by seven times by 2022. With oil prices at record highs, bio fuels have become an attractive alternative energy source for poor countries, some of which spend six times more in importing oil than on health care.

But environmentalists have warned that the bio fuel craze can do as much or more damage to the environment as dirty fossil fuels, a concern reflected throughout the report, which was released Tuesday in New York by U.N.-Energy, a consortium of 20 U.N. agencies and programs.

Much of the Amazon Rainforest is being destroyed every year to produce bio-fuel crops. So now we see the consequences in Africa. With a world population expected to reach 9 billion by 2025, this could become a massive tragedy with starvation leading to military conflict and genocides several times bigger than what happened in Rwanda as a consequence of ethnic conflicts. Bio-fuels are not a green solution. We cannot pretend to save the planet by condemning billions to death by starvation. Many oceanic areas have been almost completely depleted of life and now we are facing the prospect of eradicating entire inland habitats.

In a 2005 study, Cornell University researcher David Pimental factored in the energy needed to grow crops and convert them to bio fuels and concluded that producing ethanol from corn required 29 percent more energy than ethanol is capable of generating. Pimental found similar problems with making biodiesel from soybeans. “There is just no energy benefit to using plant biomass for liquid fuel,” Pimentel says. 

European Union countries must drop their bio fuels targets or else risk plunging more Africans into hunger and raising carbon emissions, according to Friends of the Earth (FoE).

Natural disasters including floods in Pakistan and a heat wave in Russia have wiped out crops in recent weeks and intensified fears of widespread food shortages.

Half of the 3.2m hectares (ha) of bio fuel land identified – in countries from Mozambique to Senegal – is linked to 11 British companies, more than any other country.

A market has been created by British and EU laws requiring the blending of rising amounts of bio fuels into petrol and diesel, but the rules were condemned as unethical and "backfiring badly" in April by a Nuffield Council on Bioethics commission. In the UK, only 31% of bio fuels used meet voluntary environmental standards intended to protect water supplies, soil quality and carbon stocks in the source country.

Another risk is that bio fuel use could increase carbon emissions by increasing destruction of forests when displaced local farmer’s clear land. The Institute of European Environmental Policy recently said carbon released from deforestation linked to bio fuels could exceed carbon savings by 35% in 2011 rising to 60% in 2018. Currently, this indirect impact is not considered in European sustainability guidelines.

"Use of large-scale mono cropping could lead to significant biodiversity loss, soil erosion and nutrient leaching," it said, adding that investments in bio energy must be managed carefully, at national, regional and local levels to avoid new environmental and social problems "some of which could have irreversible consequences."