Don't forget, while we are being frugal, there are Billions (yes, with a B) of people in the world who live on $1 or $2 a day. If the price of their food goes up even a little it can be disastrous for them.

And while humans are adaptable, as MissSeeton says, there is going to be a lot of suffering while the changes are taking place. Large farming operations can't just move to the next state overnight because climate conditions have changed.

Ask the cattle farmers in the south why they didn't take all their cows and move somewhere rainy.... Doesn't work that way.