I'm starting to think that articles like this are heading in the right direction in the wrong vehicle.
Wasting food is bad, as is wasting any resource (food, people, time, ...)
But tying this message to three other highly debatable messages ("Food waste generates methane, a greenhouse gas with an impact on global warming that is 21 times greater than that of carbon dioxide") is even worse, because it represents a missed opportunity.
I happen to believe that (a) Global warming has been taking place for over 13,000 years - ever since the Wisconsin ice-sheet started melting
(b) Carbon Di-oxide is good for plants, and that means good for us.
(c) The oceans are very good at absorbing excess CO2 (see e.g. The White Cliffs of Dover), there's just a time lag that is longer than 70 years
(d) The earth is quite good at recycling methane, too (I suspect that the dinosaurs, vegetarians mostly, produced more methane than cows do today)
In consequence the article turns me off on 4 counts before it gets into its message.
Any reader who disagrees with any ONE of those four points is liable to adopt a defensive or negative attitude to the remainder of the article.
I can't see what's wrong with just saying "serving food that can't be eaten is insane", and develop that idea, without discussing the relevant safety merits of SUVs (which the author didn't do) or whether Rob Ford should close libraries (ditto).