Low-Carb and Gluten-free diets haven’t stopped the nation’s fresh bread market in Australia which is growing at 2.1% a year and is currently worth … wait for it … $2.9billion. Around three-quarters of Australian shoppers are buying fresh bread each week, but what do you know of the emissions associated with the bread? Slicing up the processes involved in a loaf of bread arriving on a store shelf is a good exercise in understanding all the hidden activities go into food production and total up to form a carbon footprint of what you eat.CSIRO took a good look at a loaf of white bread and conducted a life cycle assessment to determine it eco-friendliness. Here’s what they found.Firstly, you would be aware that most bread is pretty much wheat and water, so land use considerations at an agricultural level were considered. Monocultures like wheat, impact biodiversity and native flora and fauna. Australian rain-fed wheat crops use minimal additional water. So that’s good. But if there’s sugar involved, then there’s a hell of lot of irrigation as well. On the farm, nitrogen fertilisers, one of the biggest factors for carbon emissions, are used. The wheat seeds are planted and harvested using machinery that uses diesel. By the time enough wheat to make a loaf of bread leaves the farm, it’ll have generated, on average, around 200g of greenhouse gases per kg of wheat.Wheat is transported to a mill (add transport emissions) then machinery mills the wheat to flour (add electricity emissions). It’s transported again to a bakery and added with other ingredients such as yeast, canola oil and vinegar, all of which have their own carbon footprints to contribute to the recipe. Significant amounts of coal-based electricity are involved in milling and baking. As a result, a kg of flour has about 270g of “embedded” greenhouse gas emissions, including those of the wheat growing. Choice of packaging – usually soft plastic bread bags which are difficult to recycle – add to the carbon footprint.How the finished loaf was bought also adds to its carbon footprint. Did the consumer drive to the shops to buy it or walk? If you toasted your bread, you added about 30g of CO2 for two slices of toast just for the power to use the toaster. You carbon footprint can blow out according to what you then put on your bread, for example butter will around an extra 125g of CO2 per slice (15 grams of butter).After crunching all the numbers, a reasonable assumption is that around 550g of CO2 per loaf, or some 25g per slice, goes into your bread before anything is added. So go easy on the butter – dairy products emit a considerable carbon footprint. Better hold the cheese too.