There is room for improvement, and there is significant financial incentive to realize that improvement. That said, I'm not sure that measure is the whole picture. If we are losing 30% of our food to the supply chain, what is the alternative? Perhaps we could farm things more locally and shorten the supply chain? If we did that, would we still get 100% of the yield of the old approach? What I am saying is that if we try and fix the waste problem, it would very like be at the expense of reducing yield. The extreme example is the tomatoes I am growing in my back yard. None of them will be wasted, but I'm fairly certain that the yield per square acre is absolutely atrocious.

I call it an unavoidable cost of making sure people have food on the table. There is no way on this planet that you can design a supply chain that you produce the same amount of food that is consumed. This isn't parts that get put in some widget, people have different tastes at different times. I'm honestly surprised its only 30% given the fickle taste of people.

The CO2 production will reduce as we steadily change from diesel to electric. Ocean going vessels are just environmental problems that treaties seem to ignore.