Those surpluses are mostly exported, and besides that you're missing the forest for the trees. Individual action, even if completely efficient and pervasive, would not be enough to fix this problem.
That is a related but distinct point. Solidarity and collective action are required, but when we accomplish those we'll be able to just eat and burn what is produced domestically.
This isn't really an excuse in e.g. USA, which produces surpluses in both of these commodities.