Is Green Feul - Worth it?

I have been interested in Bio-Diesel technologies and other Energy generation techniques. There has been lots of debates at Devos and all around the world regarding the use of Green Fuel. Are these efforts and Publicity going to help.

Fuel generations techniques being discussed:

1) Petrol 2) Nuclear forms (Few ships use this technique) 3) Ethanol from Sugarcane 4) Ethnol from Rapeseed 5) Ethanol from Jatropha 6) Ethanol from Corn.

An article which i came aross regarding the effect of moving from normal petrol fuel to ethanol suggests "Using rapeseed and corn for biofuel manufacture can actually produce between 50% and 70% more greenhouse gases than using fossil fuels". I have come across many articles regarding the same.

I personally belive that moving to Alternative food based fuel would have following effects:

1) Increase in Corn Prices. (U.S has severe problem in this area in the next 5 years)
2) Increase in Sugarcane prices.
3) Increase in Greenhouse gases caused to produce these Alternative energy fuels.
4) Deforestation, which will lead to increased carbon emissions and loss of biodiversity; (Scotsman News Article)

5) Loss of land for food crops, which could send prices higher;(Scotsman News Article)

6) Environmental damage from lorries transporting the fuels.(Scotsman News Article)

I guess the big steps toward alternative energy should be properly evaluated.