The introduction of Britain's Renewable Transport Fuels Obligation (RTFO) means all petrol sold in the UK will have to include at least 2.5% biofuels, rising to 5% by 2010.
This follows similar mandates in much of continental Europe, the US and, closer to home, Queensland.
But some scientists and green groups argue that biofuels do more harm than good; that rather than helping tackle climate change, biofuels actually contribute more greenhouse gases, through deforestation and the use of fertilisers, than they save.
This argument has yet to be resolved, but one thing that cannot be disputed is that biofuels are a prime culprit in rapidly rising food prices around the world.
In some cases, food crops such as corn and soy beans are being diverted to biofuel production. In other cases, land that used to be planted with food crops is now being cultivated with biofuel crops.
The net effect is upward pressure on food prices, which have risen by 83% globally in the past three years.
World Bank President Robert Zoellick has warned that in many countries poor people are spending 50-75% of their income on food, and up to 33 countries are at risk of social upheaval because of rising food prices.
Biofuels are certainly not the sole cause of rising food prices. Zoellick says a "perfect storm of things coming together" is causing higher food prices - these factors include financial market speculation, high energy prices and increased demand for food. He could have added to this list World Bank and IMF policies that have discouraged subsistence agriculture, and European Union food subsidies that have made undermined the competitiveness of Third World cash crops.
But the biofuels push is certainly one of the prime drivers in the increasing unaffordability of food.
In the past two years the price of corn in the US has more than doubled, driven partly by demand for alternative fuels such as ethanol. This has been tough on many Americans, but has been disastrous for people in neighbouring Mexico where corn is a staple food.
In the past few weeks alone, there have been food riots in many developing nations, including Indonesia, the Philippines, Egypt and Haiti, as well as several African nations.
"When millions of people are going hungry, it's a crime against humanity that food should be diverted to biofuels," Indian Finance Minister Palaniappan Chidambaram said in an interview with the Wall Street Journal.
UN Special Rapporteur for the Right to Food Jean Ziegler also used the repeated the "crime against humanity" phrase in an interview with Berlin radio.
When the move to boost biofuel production started, it made sense to use surplus sugar and tallow (waste animal fat) as biofuel feedstock. But the growth of the biofuels sector has been so fast that it has produced unintended consequences.
It is clear now that producing fuels from food crops, or from ground that can be cultivated for food crops, or from palm oil plantations in cleared rainforests, is neither environmentally nor socially responsible.
Biofuels advocates must now look to "second-generation" feedstocks such as algae, crops grown on land not suitable for normal agriculture, and cellulosic technology, which can be applied to non-food crops such as grasses and to waste products such as food scraps and grain crop stubbles.
Even most environmentalists are now saying that current biofuels policies are mistaken. The time has come to abandon these misguided schemes.
