Why not? Bulk shipping is really efficient, local farmers markets can easily be worse for the environment than going to a supermarket. A Semi moving 35 tons at 7 MPG is 25 times more fuel efficient vs a ford F-150 moving 1/2 ton at 20 MPG and trains or boats are even better.

In the end fuel costs money so more efficient logistics is often good for the environment. Buying local makes a lot more sense if you live in a farming community than a port city.