Food Miles or Food Myths?
There's a mythconception that the reason food is so carbon intensive is because of “all the transport and packaging” - Not true! There's no doubt that the rising distance food travels is a cause for concern, but transport plays a relatively minor role in overall carbon costs -80% of emissions are created before produce leaves the farm gate. One US study suggest only 4% of the total greenhouse gas emissions associated with food production were related to transport. Most of the carbon cost is associated with fertiliser (which requires 1.5 tons of oil to produce 1 ton of nitrate fertiliser) cultivation, and livestock.
Another complication in the food miles equation is that food transported over distance can be more energy efficient than its local counterpart. One study claims that New Zealand lamb is four times more carbon efficient after its 11,000 mile boat journey to the UK than British reared animals – mainly because NZ lamb is reared on open grassland rather than being fed soya and cereals. A DEFRA study found that tomatoes transported from Spain were more energy efficient than tomatoes grown in heated greenhouses in the UK. Think for a second and its obvious why – a lorry from Spain carrying 40 tons of tomatoes travelling 1000 miles uses around about 625 litres of fuel. Heating a polytunnel from September until May uses 76 litres of heating oil per square meter of floor space - 7600 litres to heat even a small 100 square meter tunnel.
food doesn't have wings...
The worst kinds of fruit and vegetables are out of season crops and out of season crops that have to come by air are the worst of all. Mike Berners -Lee compares the carbon intensity of locally grown strawberries (600 grams per kilo) with out of season strawberries flown in or grown in hothouses (7.2Kg/kilo). There's no need to go through a list – there's a fairly simple way of gauging the carbon intensity of food – if it has to be air-freighted, if it's very light in weight and comes in big bags (leaf salads etc) or its grown in a hot house (cut flowers, fresh herbs in winter etc) its probably has a big footprint – just transporting all that air around alone is wasteful – and a lot of the food in the bags has almost zero energy value. The more local, seasonal, and lower volume of air to produce (think packs of crisps compared to potatoes!) the better the carbon efficiency. ...
but beef is the real beef...
The carbon cost of the odd bag of baby spinach pales to insignificance compared to animal products – milk, steak cheese all weigh in with heavyweight carbon counts, with methane from the cow contributing the biggest part of the emissions. 1 kilo of steak creates over 15 kilos of carbon,1 kilo of cheese, 12 kilos carbon. The count is a lot lower for chicken and pigs but even higher for sheep. It's true that a hill raised sheep has a fairly low carbon intensity – but average out the cost of all that ruminant methane, the deforestation to grow the soya, for all the animals eaten every day across the planet and a kilo of lamb costs a shocking 18 kilos of carbon. Us carnivores have to accept that meat in general is very carbon intensive way of getting food.
...and rice is not so nice...
Having upset the carnivores, macrobiotics are going to be unhappy to find the average carbon cost of a kilo of rice is 4 kilos CO2e – 4 times higher than wheat (because of methane from paddy fields!) – to find out more about the carbon footprint of individual products and look at food in general - get the book, (Profile Books - “How Bad are Bananas” ISBN978 1 84668 891 1) It's full of useful information and well worth reading to expand your carbon conciousness (our thanks to Mike Berners-Lee for allowing us to use his figures)
... while waste is worst of all
So transport is bad, and meat is bad and rice is bad - but these are the lesser denizens of the the food chain hell. The true devil is WASTE! One third of all food produced is wasted. There's a lot of hand wringing at the moment about how we can possibly produce enough food to feed 10 billion people – some voices quietly assert that we do already and a third of it is wasted. WRAP reckon cutting all the UK's food waste is the equivalent of taking 1 in 4 cars off the road.
It's true that not all waste happens at home – the way food is marketed means that there are losses all the way down the supply chain but cutting your own waste can make a big difference to your carbon footprint. It's an important difference too. Cutting waste obviously cuts the carbon and energy cost of production, but food in the waste stream produces methane, a 30 times more powerful greenhouse gas than carbon dioxide – so cutting out food waste is a high value way of reducing your carbon footprint and it will save you money.
A quick list of things to reduce the carbon footprint of your food
This list sounds very obvious - but if a third of all food produced is wasted we all must be at least a part of the problem. Food in a pan with a lid _at a gentle simmer cooks just as quickly as one boiling fast under a full flame but uses half the energy -
- only cook what you can eat
- eat less meat, if you buy a chicken boil the carcase for soup, if you buy a fish get the fishmonger to fillet it, make stock with head and bones
- Avoid air freighted food
- eat seasonally as much as possible
- grow your own salad and herbs
- make cooking as economical as possible – use lids – boil at a gentler simmer, make sure ovens are filled, cook with gas
Visit http://www.lovefoodhatewaste.com/ - there's a wealth of tips on storing food, recipes and info about food waste. Growing your own can be a real carbon saver - especially leafy veg, herbs and other high volume low weight products - you can grow your own even in the smallest of spaces.