In this extract from her new book, Patrice Newell says environmental policy must begin at the farm gate

The juggernaut of globalisation has been inescapable for Australian agriculture. From the start, merino wool was a major export earner, and it still is. Australia has 70 million sheep and wool reaches markets far and wide. Overall, 70% of all our primary produce is sent overseas, including much of our organic produce.

Agriculture is as much an export business as mining, so when I see asparagus from Peru, garlic from Mexico and cherries from California on supermarket shelves, I wonder why we still need to import so much food. The answer is simple: all year-round supply and money. Cheap is the name of the game. Cheap food is as political as cheap power and the supermarkets are happy to comply. The global shopping cart is at a store near you and on your computer.