According to WRAP, each year 330,000 tonnes of milk is wasted in the UK, 290,000 tonnes of this happens in consumer homes. This is the equivalent of 490 million pints of milk wasted each year as a nation or 18 and half pints per household! So here’s why you SHOULD cry over spilt milk.
1. It’s a total waste of money – We, as a nation, are throwing £150 MILLION worth of milk down the drain (WRAP)
2. Greenhouse gases – dairy cow farming is associated with HUGE amounts of global warming gases such as methane, nitrous oxide, and carbon dioxide. The more we waste the more we increase demand on farming, increasing these impacts.
3. Water consumption – Whilst the exact numbers vary research suggests it takes in the region of 1050 litres of water to make 1 litre of milk, tying up massive amounts of the worlds freshwater supplies.
4. Waste – all of the options for disposing of milk wasted in consumer homes have some pretty nasty side effect, including potentially killing of fish…curious as to how? Read on….
So why is dairy waste one of the big bad’s of food waste?
As always when we look at the environmental impacts of food waste we need to consider the environmental cost of making the product as well as that of wasting it. So with dairy we start with the cows. Last week we talked about how much environmental damaged we could prevent by feeding treated surplus food to pigs instead of growing crops to feed them. The same issue stands for cows with a huge amount of cereal being used to thicken out their feed. This means all the water and energy (not to mention the deforestation, soil erosion and eutrophication) which goes in to farming cereal also counts towards the impact of milk production.
One of the largest causes of greenhouse gases in cow farming is ‘enteric fermentation’ – this is a fancy pants, scientific way of saying: farting. Ok, that may be over simplifying it but it is the digestive process which leads to excess methane, which is expelled by farting so, pretty close! According to the WWF there are over 270 million dairy cows in the world – that is A LOT of methane, which you’ll probably remember from previous posts, is over 26x more potent than carbon dioxide in speeding global warming.
Further methane is released from manure and nitrous oxide is released from both this and from the fertilisers used to grow feed for the dairy cows – it sounds tenuous but all of this has to be considered as linked to the production of milk.
Then there’s the water waste. Animal agriculture worldwide uses up 2,422 BILLION cubic meters of water, one-quarter of the global freshwater supplies, and 19% of this goes to dairy farming (Hoekestra, 2012). The study discusses how the first step of aiming to reduce consumer-related water waste (only 4% of which occurs in consumer homes) should be revaluating our diets to consume less water-intensive foods. Crazy isn’t it, we all remember to turn the tap off whilst brushing our teeth but you don’t really think about throwing out the last bit of milk as impacting water waste. The water tied up in dairy production is caused by a variety of water uses including growing the feed for dairy cows, water for dairy cows to drink and cleaning the dairy equipment between each milking.
The thing to remember here is that when we waste food we don’t just waste the impacts done farming and producing that one bit. We place an increased demand on the agriculture system which means they keep over producing. If we take in to account that estimates put global food waste at 40% of food produced what we’re saying is that we are demanding farmers practically double the amount of food they produce, just so we can throw half of it away. That means twice the deforestation. Twice the biodiversity threat. Twice the global warming gases. Twice the water wastage. I could go on.
A key point made in a 2011 review of dairy’s environmental impacts is that “dairy products are associated with large amounts of GHG and other environmental impacts when compared with most foods of similar nutritive content”. Essentially what they’re saying is that we can get similar nutritional benefits as that from dairy from foods which carry a lower environmental impact. An example given of this is a study which found that cheese and peanut butter have similar protein and [healthy] fat levels but comparatively vastly different environmental impact levels. Cheese came in at 5.9 kg of CO2e per kg of product as compared with peanut butters 0.17 kg of CO2-Eq/kg.
What about waste?
When milk is wasted in consumer homes it normally goes one of two routes – down the drain or in the bin.
What about when it goes in the bin? Unfortunately, there’s very little research focusing on the environmental impacts of disposing of milk alone, for the most part it’s tied in with general ‘food waste disposal’. However, we do know that dairy and meat are two of the highest product types for disposal methane, meaning any product which goes to landfill will have a high environmental impact as they slowly leak methane out. Incineration is a commonly practiced alternative in the UK which, whilst being lower in the massively impactful methane, still produces carbon dioxide, nitrogen oxide and nitrous oxide. Additionally, as with landfilling and pouring it down the drain, on top of the individual impacts of the waste disposal each of these methods carry with them the environmental impact of the farming and production of milk.
Can going organic help?
Unfortunately, research suggests not. A 2003 study found that organic milk production actually increased methane production as a result of the lower amount of milk each cow produces, increasing the number of cows needed to meet demand and therefore the amount of enteric fermentation (farting). However, lower fertiliser use in growing the food for organic dairy cows does mean it results in lower eutrophication levels (less impact on surrounding water).
However, the conclusions from the study also highlight that the farms explored in the study were still largely experimental and there was potential for improvement of organic dairy farming which could change the outcome. So for any agricultural researchers out there: we need some more up to date research please!
What can we, as consumers, do to reduce milk waste?
1. Keep milk in the fridge ALWAYS
I don’t know about you guys but I used to be a villain for pouring my cereal and milk and then leaving both on the side until I’d eaten, then clearing away. Seems totally innocent right?! But increasing the temperature of milk gives it time to start growing bacteria, quickening it’s spoilage.
2. Check the temperature of your fridge
It’s all very good to make sure you keep your milk in the fridge but what if it’s running at the wrong temperature? WRAP’s research has found that a typical fridge in the UK is running around 2 degrees warmer than the 0-5 degrees recommended by the Food Standards Agency. This will affect not just milk but the lifespan of many food products, so make sure to check it and correct it!
3. Buy smaller portions
It’s every Brits worst nightmare – you come downstairs in the morning, pour yourself a lovely cup of tea and the open the fridge to see…. NO MILK! DUM DUM daaaaaaaa! (For our American friends, pretend I’m talking about coffee). So we tend to over purchase, we’re all guilty of it. The ‘better too much than too little’ mindset, but this is definitely not the case when it comes to food waste. So what’s the solution to this, buy smaller portions and….
4. Have an emergency pint in the freezer
A startling amount of people don’t know you can freeze milk, but-chya-can! You do need to make sure to defrost it safely though so leave it in the fridge to thaw, not on the kitchen side. This will take a little while to defrost but keeps the milk safe. So make sure to check the night before if you need your emergency milk for the morning and if so pop it in the fridge overnight.
5. Keep an eye on use by and freeze milk in ice cube trays.
For milk which it nearing its end you can always pour it in ice cube trays giving yourself handy single portion milk cubes. These can be used to make iced coffee or smoothies as they are or you can pop just as many milk cubes as you need in a mug and leave them in the fridge overnight to melt so you have the perfect amount of milk for you coffee the next morning.
6. Use up any little bits with any extra fruit in your fridge and make yourself a nutritious smoothie
Alternatively, if you’re on the last day you’re happy to use the milk why not grab any extra fruit or veg in your fridge and get adventurous with smoothie recipes? Turn it in to a family challenge and see who can come up with the yummiest recipe!
De Boer, I. J. (2003). Environmental impact assessment of conventional and organic milk production. Livestock production science, 80(1-2), 69-77.
Hoekstra, A. Y. (2012). The hidden water resource use behind meat and dairy. Animal frontiers, 2(2), 3-8.
Lesschen, J. P., Van den Berg, M., Westhoek, H. J., Witzke, H. P., & Oenema, O. (2011). Greenhouse gas emission profiles of European livestock sectors. Animal Feed Science and Technology, 166, 16-28.
Milani, F. X., Nutter, D., & Thoma, G. (2011). Invited review: Environmental impacts of dairy processing and products: A review. Journal of dairy science, 94(9), 4243-4254.