HomeArticles All the foods and drinks we produce are responsible for some greenhouse gas emissions, whether those emissions come from flying that produce around the world or heating the greenhouses it’s grown in. But do you know what foods are the most carbon-intensive? What is a carbon footprint?Calculating the ‘carbon footprint’ of food is a way of measuring how much carbon dioxide and other greenhouse gases, like methane, are emitted into Earth’s atmosphere during that food’s production. It takes into account the whole life cycle of the food, from the equipment and nutrients needed to grow or raise it, to the transport that gets the food to our tables, and even how much of that food is typically wasted.1Given that a quarter of global emissions come from food, if everyone shifted their diet even a little could have a big impact on our planet.2How food carbon footprint is calculatedThe amounts of greenhouse gas emissions vary from food to food, with animal products like beef at the higher end of the scale, and plants like lentils at the low end. But it’s a complicated picture, and the carbon footprint of one type of food can be different depending on how and where it’s produced.2The units used for carbon footprint are kilograms of carbon dioxide equivalents (CO2eq), which take the impact of gasses like methane, and convert them to the equivalent amount of carbon dioxide, to make comparisons easier.If you’re aiming for a low-carbon diet, here are 4 things to consider when grocery shopping:1. Beef and lamb are the most carbon-intensive foodsYou (probably) guessed it: meat is the most carbon-intensive food, with beef and lamb topping the list. Rearing cattle results in emissions of 15-27 kilograms of emissions per kilogram of beef, while a kilogram of lamb can result in up to 39kg of emissions.1Agricultural livestock alone could contribute 14.5% of human-made greenhouse gas emissions. (Though some experts have said the 14.5% figure is inflated, and others think it's too conservative).3 The biggest contributor to this is something called “enteric fermentation” – a process in which the bacteria that break down food inside a cow’s digestive system produces methane. The methane is then released into the atmosphere via… cow burps (and not, as is commonly assumed, farts – though they do contribute a little).4For food like beef with a high carbon footprint, transport is a low contributor to its overall environmental impact.12. Cheese also scores high in carbon emissionsCheese comes in at around 10-14kg of emissions per kg of food, which is unsurprising when you consider it’s usually made from milk produced by cows – and, as we know, cattle are among the most carbon-intensive animals to rear. The carbon footprint of milk itself scores lower, at around 2kg of emissions per kg of milk.13. Fruit and vegetables have a lower carbon footprintFruits and vegetables, on the whole, have a lower carbon footprint than animal products. A kilogram of potatoes, the most carbon-intensive plant-based food, is responsible for 2.9kg of emissions. Lentils come in even lower at 0.9kg.1Because they have a lower carbon footprint in total than foods like beef and other meat products, transport plays a bigger role in the overall carbon footprint of plant-based foods – so in general looking for locally sourced veg will mean lower emissions.4. Transporting food contributes to emissions, but so does energy useBut it’s worth remembering that calculating a food’s carbon footprint is not always as simple as looking at how far away something was grown. Tomatoes, peppers, and cucumbers grown in the UK can end up with bigger carbon footprints than turkey and chicken, because of all the natural gas and electricity used to heat the greenhouses and keep the plants warm enough.5In that case, growing tomatoes in a greenhouse in Spain where the climate is warmer, and then transporting them to the UK might actually result in fewer carbon emissions than growing those tomatoes in the UK.Making environmentally-friendly dietary choices Created by Paulina Cerna-FragaIf you want to reduce your personal food carbon footprint, diet could be a good place to start. Switching to more plant-based foods, or even just reducing the amount of meat and dairy you consume, can bring your carbon footprint down a long way. The carbon footprint of the most climate-friendly protein sources (like pulses) is up to 100 times lower than those of the most climate-unfriendly beef and lamb production,6 and cutting meat and dairy could reduce your personal carbon footprint by two-thirds.2Some last tipsIf you can’t stomach that, one thing everyone can do is reduce the amount of food they waste. Up to 1/3 of all food around the world gets wasted.7 To help lower this, buy and cook only what you need, and try to use up all the food in your fridge (especially carbon-intensive food like meat and dairy products) before it goes off. Eating seasonal, locally-grown produce is another practical step you can take.