Probably, for with the finest growing areas moving north and south, they get smaller. And the sea will yeald less due to i.e. less possible saturation. So, in short, what's coming from under the ice, and slowly, is barren rock, while we are beginning to "loose" very good areas.
Swings in the whole eco-system of plants and animals are also going to give a downswing at first.
Try solving the riddle of declinine of U.S. Bees, and look at the effect.
(my guess is that it's actually not GW, but the effects are more than just honey....)
For a country like mine BTW, a little warming is just fine