Study up on supply and demand.  That will explain a lot of it.  
Ethanol is not causing the prices to rise any higher so much as it is keeping prices higher.  The base cost due to ethanol is already in the price, but as part of demand it does have an effect.  And it is definitely helping keep the price high.  
Transportation price is a good component of it.  A big part of that is the cost of the fuel, a real big part, but where it is coming from affects it too.  It is cheaper to haul grain from Kansas to Missouri that from the Ukraine to California.
Grain is a world wide commodity.  It is not just the weather in the US that matters but weather and other growing conditions worldwide.  Floods, fires, or droughts in Australia, Eastern Europe, or much of Asia will affect our grain prices.  
Some of the developing world in seeing an increase in their standard of living.  Not just China but India and many other places.  They demand a different diet now that they can afford it.  That puts the demand on certain things higher.
There are a lot of causes and effects I'm not mentioning but maybe this will give a few clues.  
The simple answer is that supply is not keeping up with demand and the cost of moving the supply to where the demand is keeps going up.