CNN: Eating ethically is no easy task these days. One problem is deciding which ethic is more important. Keeping third-world farmers in fair trade jobs by purchasing their produce? Or assuaging your concerns over the environmental impact of getting that produce to your kitchen by shopping locally instead? Up until recently it has been the latter concern — how food is transported — that has hogged the limelight when it comes to looking at the role the food chain plays in climate change. …