The Union of Concerned Scientists has put out this document for those of us who grow plants. It has very good information and I urge you to read it.
I have one small problem with it and it is that it mentions the now over-used 1500 miles datum. I too bought into the alleged import of this piece of information until I read the book Just Food by James E. McWilliams. So, after you read the document by the Union of Concerned Scientists, I highly recommend the book Just Food.
Read The Climate-Friendly Gardener here (.pdf format).
Over and out.