I'd hesitate to be flippant about the complexities and difficulties in the generation of food, and the market forces that it drives. And I'd certainly hesitate to claim that anyone has "better things to do".
And an admonishment against the hubris of just casually dropping deeply loaded positions like "Europe has more important things to worry about" than Africa or Ukraine. Hell even casual the separation of Ukraine as something outside of Europe.
If you took it as a personal attack, then perhaps it is just because a hit dog will holler.
But like I said the food produced by land that is urbanized would have to be imported. But that is not a bad thing. It will be very good for developing nations.
Another question worth thinking about - what landscape pollutes the air/water/land more? is it farm land or the cities?