By energy wasted on food and trash I mean the hydrogen & energy (both generally from fossil fuels) that go into a lot of the fertilizer which is used in industrial agriculture. All of the energy which goes into plastic manufacturing: fossil fuel feedstocks, cellulose and other stuff going into it, to the transport of supplies & the energy use of everything.
Yeah effective composting is a good way of doing that. I have a compost bin.
Also hydrogen gas is used to make gasoline. If fossil fuel production was heavily reduced I'm guessing it would be trivial to replace part of naptha production with hydrogen from renewable sources?
Maybe it would be redundant.