the growing demand for biofuels could lead to a shortage of food. Studies show biofuel plantations will eat up cropland, and trigger food and water crisis in many parts of the globe, especially in India and China.

There is also evidence to show biofuels will not help in carbon emission reduction, instead it will cause detrimental environmental impacts. The impacts of the growing biofuel demand will be apparent on a local level.
Carbon offsetting Many experts argue carbon emissions can be significantly reduced if biofuels replace fossil fuel in automobiles. Others argue greenhouse gases released during the production of biofuel crops can undermine the putative gains. They say that instead of promoting biofuel, conserving and growing forests will be more effective in slowing down climate change and its effects.

A paper in the August 17, 2007, issue of Science estimates carbon emissions offset by biofuel are lower than those achieved through afforestation. Renton Righelato and Dominick V Spracklen, researchers from the World Land Trust and University of Leeds, the uk, say biofuel plantations will end up emitting more carbon than they will help save (see figure: No gain).

To find out if biofuels will significantly help cut carbon emissions, the researchers calculated how much total emissions biofuels could save, comparing it to the carbon emissions which alternative land-use strategies like afforestation could save. This estimation was done for the coming three decades, a time likely to be taken to introduce carbon-free technologies to the world. It has been found that the carbon a natural forest can capture is about nine times more than what biofuels can save during this period.

For example, conversion of sugarcane to ethanol saves only about 1.78-1.98 mg (1 mg=1 tonne) carbon per hectare (ha) per year. Similarly, converting rapeseed to diesel will avoid only a range of emissions