Substitute chicken, fish or vegetables for red meat and dairy just one day a week, and your family of four will eliminate greenhouse gases similar to the amount produced by a 1200km car trip, say researchers from Carnegie Mellon University in Pittsburgh, who studied the impact of dozens of foods. Other ways to do your part:

Buy local and fresh Local isn’t better if the food is stored for long periods, using up more energy. Fresh-picked fare not only avoids long trips in fume-spewing trucks, planes and boats, but it also packs more nutrients and requires no preservatives.

Choose sun-ripened fruits and vegetables They generate fewer emissions than produce raised in heated greenhouses.

Cut back on processed foods A lot of truck kilometres go into foods with artificial sweeteners, additives, and preservatives because these ingredients are often shipped to the manufacturer from other locations.