So, let's assume we all did this. We wouldn't be foraging for our own, I hope, we'd do what we do for our meat and buy it in the store. Okay, that would maybe sort out the methane being produced by cows but large-scale farming of insects would take almost as much land and infrastructure as large-scale farming of chickens or cows or whatever, so all those 18 wheelers would still be on the roads. Sure, you can fit X million ants into a small piece of land, but those things are TINY. It's not like 1 roach = 1 cow.
Sigh. Is the UN taking a page from PETA on this one and doing something cheap and sensational? Because I'm pretty sure mandating the diets of member nations is well outside their purview.