Not sure why it would lower crop production. Also not sure why maple syrup is worth mentioning.
"Not sure why it would lower crop production." The conditions that crops need aren't based on average temperature, but rather they're based on the minimum temperature, the maximum temperature, and how long it takes to go from very cold to very warm and vice versa. With global warming the climate zones don't just shift north, but rather you get these situations where certain crops just won't grow at all. For example,…
That's a non sequitur. If certain things don't grow as well, it doesn't follow that nothing will.