Brewing up a catastro-tea
Departments Research impact and institutes 17th January 2018
This Dry January, you’re probably putting your kettle through its paces – replacing beer with healthy green teas and energising coffees. And there’s nothing more innocent than a good old cup of tea, right? Well we hate to break it to you, but that brew may not be as guilt-free as you thought.
Researchers at The University of Manchester have shown, for the first time, the environmental impact of the humble kettle through its full lifecycle. And it’s our trigger-happy behaviour with the ‘On’ switch that’s causing the most damage to the planet.
So, grab yourself a delicious cup of … cold water and let’s learn more.
Off the boil
Until now, the full environmental impact of the kettle has been unknown. It’s a mystery researchers at the School of Chemical Engineering and Analytical Science (CEAS) set out to uncover.
The resulting paper, published in Science of the Total Environment, reveals that the EU is home to between 117 and 200 million working kettles. That’s a lot of brews.
The team compared the environmental impact of plastic, metal and eco kettles from manufacture through to end of life. The main finding was that the eco-kettle has a 30% lower environmental impact than plastic and metal kettles thanks to better power efficiency. With 80% of a kettle’s environmental impact occurring during its usage stage, this is the area where the most work needs to be done to reduce its carbon footprint.
One cup or two?
So, whose irresponsible tea-making behaviour is damaging the planet? Well, if you ever fill your kettle to the top – and, let’s face it, many of us do – then hang your head in shame.
Boiling only the water you actually need for the drinks you’re preparing can reduce the environmental impact of kettles by around a third. Over the lifetime of a kettle, and across the millions of kettles in use throughout the EU, this could add up to a huge saving.
Having said all that, the researchers acknowledge that many people prefer the convenience of filling their kettle up at the start of the day so they don’t have to do it again. They recommend encouraging people to change this habit.
Another tip is to only boil the water to the temperature you need for the drink you’ve chosen. For example, green tea shouldn’t be brewed in boiling water. This simple change could also add up to an environmental saving – and a better drink.
Inconvenience food
If all this is making you feel a little guilty, we’re not finished yet. Your kettle is not the only thing in your kitchen that’s hurting the planet every time you use it. Please step forward, the microwave.
In a separate piece of research from CEAS, scientists conducted the first ever full review of the impact a microwave has on the environment from its manufacture right the way through to its disposal. And while it may have your meals ready in a flash, its impact on the health of our planet is far from convenient – in fact, it could be as bad for the environment as cars.
While their manufacture and disposal certainly harm the environment, it is the electricity these machines consume as they blast your ready meal that has the greatest negative impact. Across the EU, 9.4 terawatt hours of electricity are used by microwaves every single year. On average, a single microwave uses 537,000 watts of electricity over its eight-year life – equivalent to the power it takes to light nearly nine thousand 60W light bulbs for one hour.
CEAS’ Dr Alejandro Gallego Schmid says: “Given that microwaves account for the largest percentage of sales of all type of ovens in the EU, it is increasingly important to start addressing their impact on resource use and end-of-life waste.”
Two decades ago when microwaves became regular features in the kitchen, the device would last between 10 and 15 years. Today, owners typically throw out their microwaves when they’re between six and eight years old. This only adds to their harmful impact on the environment.
Please don’t ruin sandwiches for us too!
Sorry, but even the humble sandwich – something that distils the very essence of Britishness down to snack form – is responsible for its share of environmental damage.
Determined to rip the heart out of the heart of our home, those CEAS researchers have also uncovered the environmental cost of enjoying a sandwich – both homemade and shop-bought. While you may think about your own health when choosing your sandwich, you should start thinking about the Earth’s too – as it turns out those delicious all-day breakfast sandwiches are bad for us both.
More than 11.5 billion sandwiches are consumed each year in the UK. And in case you’re interested, chicken salad, BLT, Ploughman’s and egg and cress are among the nation’s favourite readymade sarnies, while ham and cheese reigns when we’re preparing our own.
The researchers looked at 40 different sandwich recipes and concluded that the carbon footprint of the snacks could be reduced by as much as 50 per cent if a combination of changes were made to the recipes, packaging and disposal.
Homemade sandwiches have a smaller environmental impact, mainly because the production of commercial sandwiches requires a fifth more ingredients due to food loss during the manufacturing stage. They also have to be kept refrigerated until the point of sale, whereas a sarnie you make at home can be eaten straight away.
So how can we make our favourite snack greener? Among the recommendations, the researchers suggest extending sell-by dates, which are currently on the overly cautious side, and reducing or removing certain ingredients that have a large carbon footprint, like lettuce, tomato, mayonnaise and pork products. Interestingly, the carbon footprint of a breakfast sandwich is double that of an egg and cress – although no correlation between nutritional value and carbon footprint was found.
The conclusion is that making a sandwich yourself rather than buying one readymade is not only better for your wallet, it’s also better for the planet. While there is still an environmental impact, such as the manufacturing, packaging and refrigeration of the ingredients you choose, it is far less than that of a pre-packaged sarnie. Plus, you have the option of using leftovers and keeping waste to a minimum.
And remember, however guilty you’re feeling about buying that sandwich, at least you’re not microwaving it (unless you’ve treated yourself to a microwavable sandwich, in which case you may as well fill up your kettle to the top too while you’re at it.)
We hope we haven’t ruined your lunch for you.
Words – Hayley Cox
Images – Joeri van Veen
carbon footprintCEASChemical Engineeringengineeringenvironmentkettlekitchenlunchmicrowave
