If the weather's warming

Someone posted on the bioregional list-serve a link to a map of the U.S. depicting changes in hardiness zones. Which you click play you watch the progression 1990-2006 raising heat. It's not dramatic and gives you that feel people can adapt. The message also included a reference to Albert Bates. He is a permaculture activist, laywer and author. His most recent book (which I will look for - I haven't read it) Biochar Solution is about living carbon-negative lives. I wonder if growing food is considered carbon-negative. Maybe experimenting with growing warmer weather crops  is part of that. There are many farmers doing that right now, I imagine. One farm in Battleground, WA was trying to grow olive trees when I interned there briefly in winter 2008. (Why was I there only in the winter? I liked that part of the state, and it's close to Portland. I enjoyed traveling there on intercounty transit.) There are five farms for sale in Battle Ground, WA.