it depends on what part of the vegetable might be thrown away
certain parts should not be eaten because they can be a choking hazard
if it is something that can be cut or reduced in size, then you can cut it and it to a meal
it may not sound very appetizing, but, certain parts could either be incorporated into a soup stock, or placed into a juicer and once it has been turned into a liquid you can use it as a garnish
if for whatever reason you cannot consume a portion of a vegetable, then you can either feed it to the local fauna in your neighborhood, or, you can use it to make compost

if people eat less meat then they will eventually purchase less meat
if people purchase less meat, then to make up for the loss in revenue, meat processing plants will have to reduce the amount of products they produce in a given year
which will in turn, will reduce the amount of co2 meat processing plants emit

to an extent
i live in an old house so the level of insolation is rather poor
unfortunately i do not have the necessary funds to remodel at this current moment in time
so for the moment the only way i can effectively reduce my carbon footprint, is to alter my diet, and decrease the amount of meat i consume