Originally Posted by Blue Order
With all the food we produce, it's more likely that we're taking wildlife habitat when we run our vehicles on food, than that someone would be eating EXCEPT for the fact that we're producing fuel with that food. I once saw an American official say that there is plenty of food to go around in the world, but the problem is we need paying customers.
It's actually more complicated, and much scarier than you think. Right now we can easily feed the world, but "all the food we produce" is actually produced using massive input from the oilfields. In the 1950s and 60s the world population of around 3 billion was reaching the point where food production couldn't keep up, and widespread famine was imminently expected. Fortunately, agricultural scientists were able to make astonishing breakthroughs in yields, the so-called "green revolution", solving the problem (for a time) and allowing the population to continue to grow.
Unfortunately, while we bought some time, we may have greatly worsened the long term prospects. High yield crops rapidly deplete the soil of natural nutrients, and are heavily reliant on fertilizer derived from natural gas, and pesticides derived in part from oil. A lot of crops are now grown in areas of unreliable rainfall using irrigation water drawn from both surface and underground sources, some of which requires energy input, and which eventually salinates (salts) the soil. The work of planting, tending, harvesting, and distributing food on a global scale, and the refridgeration needed to get the more perishable foods to market, are also heavily dependent on oil. Crops are increasingly grown in marginal farmland, like cleared rainforest, that rapidly erodes once the tree cover is gone.
So when oil starts to get less available there will be a huge drop in food production capacity, making it even more unrealistic to think there will be any cropland available for personal biodiesel. Any biodiesel that is produced will have to be dedicated to farm equipment and food delivery. The farmland will be much in worse shape than it was before the green revolution - nutrient depleted, or paved over, or eroded away, and a lot of the irrigated areas will no longer be useable due to salination.
And the world population will be 9 billion.