OZ Harvest is doing an amazing job of providing meals to the less fortunate in Sydney and Canberra. The food that was previously wasted and dumped in landfills is now collected and distributed to the needy through multiple charities. OZ harvest provides the logistics for the collection and distribution of the wholesome and fresh meals that are unsold or unused by restaurants, stores or institutions. Without OZ Harvest these perfectly nutritious meals would have simply wound up in the garbage and would have been left to rot in a land fill. OZ Harvest has been recognized by the Prime Minister of Australia for the wonderful accomplishment of providing over four and three quarter million meals since the organization began their operation back in 2004.
The operation started with a single delivery van and has now grown to six delivery vans making daily trips to and from restaurants and stores to the charities OZ Harvest serves. The current operation is set to deliver approximately one and a half million meals in 2010. When I first heard about the wonderful work being done by OZ Harvest, my heart was of course warmed by the provision of food to the needy. But immediately after this thought, it dawned upon me that the world was also being saved from tons of carbon emissions by food being used for its rightful purpose and not simply rotting in a land fill. I contacted OZ Harvest last week and told them if they provided me with their information on the number of meals, the calorie content and make up of the meals, and the quantity of diesel and electricity they use, I would model their negative carbon footprint. Yes OZ Harvest has a negative carbon footprint that I will explain further.
First one has to understand the composition of food and how food is carbon rich. We measure nutritional value in Calories. A Calorie of food value is actually a kilocalorie of energy. This is the amount of energy to heat a liter of water one degree centigrade. Just as natural gas burns on your stovetop to provide heat to boil water in your kettle, food burns within our body to provide heat and nutrition to our muscles, organs, brains and blood. The meals OZ Harvest provides weigh 300 grams and have a typical nutrition value of 800 Calories. These Calories of food nutrition come from the breaking down of the chemical in the food. These chemicals are fats, proteins, and carbohydrates. Food also has moisture and fiber that do not provide chemical energy. Fats are typically composed of 80% carbon, proteins around 50%carbon and carbohydrates and fiber are approximately 40% carbon. In our bodies we use oxygen to react with our food and besides the energy we gain from the food we exhale carbon dioxide and moisture. In a land fill the food is broken down by either one of two methods. Aerobic breakdown that is similar to our bodies where oxygen and the food combine to yield carbon dioxide and moisture. But much of the food in the land fill does not contact oxygen and the food then rots without air or is anaerobically digested. In this case the gas emitted from the land fill is methane. Methane is a wonderful cooking fuel but when emitted from a land fill it is a terrible greenhouse gas with twenty one times the greenhouse effect of carbon dioxide.
I developed a spreadsheet that analyzed and calculated the mass of carbon in the food that would have been wasted, the mass of carbon that remains as a solid in the land fill and the respective mass of methane and carbon dioxide that would have been emitted from the food decomposing in the land fill. I then calculated the carbon emission of OZ Harvest’s fleet or trucks and the corresponding carbon emissions for the electricity generation for the electricity that OZ Harvest purchases and after a series of tedious mathematical manipulations I can independently vouch that at a minimum OZ harvest has had a negative carbon footprint of 3,400 metric tons of carbon dioxide equivalent. This is equal to taking off some 1,044 cars that drive 20,000 kilometers with a fuel consumption of 7 liters of petrol per 100 kilometers. In 2010 with the expected number of meals provided to reach 1.5 million, OZ Harvest will have a negative carbon footprint of some 1,074 metric tons of carbon dioxide. This corresponds to removing 330 mid sized cars off the road for the year.
I applaud the work of the team at OZ Harvest for keeping two birds alive with one stone. These birds are humanity and the planet that humanity occupies.