Friday, October 24, 2008

Global eating equals global warming

Eating is an indispensable habit and a bigger part of our lives than just providing nutrients and energy; it defines us. According to Jean Anthelme Brillat-Savarin, a 19th century gastronome, “Tell me what you eat and I will tell you what you are.” This quote, better know as “you are what you eat”, strikes such a powerful chord with us that is has been repeated through the ages and most people (including me before I wrote this) have no idea who first said it. But as people become more numerous on this planet, it’s becoming apparent that not only are we what we eat, but the world is what we eat as well.

With all the climate change talk about reducing greenhouse gas emissions this election, people are looking to their cars to help curb their personal emissions but it may be that the kitchen is a better place to start. A recent study in Environmental Science and Technology by Christopher Weber and Scott Matthews indicates that the average US household produces almost twice as many greenhouse gas emissions through food consumption than through driving. These emissions include the energy that goes into the production of the food, transporting the food from the farm to the retailer and other energy uses such as refrigeration and lighting.

I decided to find out for myself what kind of impacts my diet could have on climate change. After a little bit of research I found eatlowcarbon.com, a site that calculates your greenhouse gas emissions for different meals in grams of carbon dioxide. The calculator was put together by the Bon App├ętit Management Company, an online catering company that strives to provide both “culinary expertise and commitment to socially responsible practices”. They provide a thorough list of the sources they used to develop their tool for those wishing to do more research. I discovered quite quickly that small changes in my diet could make big changes in my emissions and that I could start making a change first thing in the morning at the breakfast table.

On weekdays, I like to keep breakfast simple with either toast and jam or a bowl of cereal. Surprisingly, that simple decision between two rather mundane choices meant the difference between 1224 g CO2 for the bowl of cereal and 103 g for the toast and jam. This means that over the course of a year, eating toast instead of cereal would reduce my personal emissions by over 400 kg of CO2, the same amount of emissions created by driving an average car 1500km. The reason that emissions are so high for a bowl of cereal has nothing to do with the cereal itself, but the milk. Dairy products and other animal products take a lot more energy to produce than food crops. This is because about 90% of the food an animal eats is used for movement and metabolism and only 10% goes into the meat and dairy products that are sold as an end product.

Lunch and supper provided their own surprises. With a cheeseburger and fries coming in at almost 2000 g CO2, I decided to look for which foods might have a smaller impact. My best bets were chicken or fish if I wanted meat (400-700 g CO2) but if I cut the meat out I could get down as low as 300 g CO2 with a vegetable stir fry.

While few people would say it is realistic to eliminate meat and dairy products entirely from our diet, some important organizations, such as the United Nations’ Food and Agriculture Organization, suggest reducing the amount of meat consumed starting with one meat-free day per week. Dr. Pachauri, head of the International Panel on Climate Change, told The Guardian, “in terms of immediacy of action and the feasibility of bringing about reductions in a short period of time, it clearly is the most attractive opportunity.”

Cutting down greenhouse gas emissions other ways is also possible but it is not as intuitive as you would think. For example, buying organic produce, because they use less nitrogen can reduce you emissions but when you buy organic meats the opposite is true. Animals raised organically take longer to reach the desired weight meaning they eat more food over their lifetimes than industrially raised animals. Also, while buying local is important to support local food producers, the emissions reductions aren’t as important as buying food that is less energy-intense to grow because transportation is only a relatively small part of food’s greenhouse gas emissions (11%) when compared to the emissions involved in food production (83%).

I encourage everyone to try this calculator. Because calculators like this one are greatly simplified, they do not give perfectly accurate results, but they do provide a reasonable estimate and at the very least can help consumer pinpoint which parts of their diets are the most responsible for greenhouse gas emissions.

As seen in the October 8, 2008 issue of the Brome County News

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