Forget climate change (don't, actually, it needs urgent attention) – you've done worse things for the planet today than starting your car.

There’s a tarot card called ‘The Knight of Cups’. This intrigues me. Not (just) because I’m a full-blown female Fox Mulder who badly wants to believe in divination, but because my surname is ‘Knight’ and lately, I’ve been really worried about coffee cups. Specifically, the billion cardboard culprits we waste in Australia each year.

Aimee Knight is a freelance writer. If she’s awake, she’s thinking about gender, sexuality, movies, animals, or Bruce Springsteen.

Fortunately, The Knight of Cups is a good card to uncover. It’s said to represent change, opportunity and ideas. Knights often come bearing messages, and I’m no exception: takeaway coffee cups are not recyclable.

The ostensibly paper specimens are lined inside with a layer of plastic (methane maker polyethylene, for those playing at home). This keeps your coffee warm, stops hot liquid from leaking on your mitts, and renders the cup an environmental pest. When we throw out about 2,700,000 per day across the country, it’s fair to say these pests have now reached plague proportions. Oh, hello 60,000 extra kilos of landfill produced per annum. I didn’t see you there.

Wait, yes I did. You’re huge. You weigh as much as twenty-six white rhinos. We could line your cups up end-to-end and cover the perimeter of this continent seven times. We could hand you over to Jeff Koons and keep him in the public art installation racket for the rest of his life (Cuppy: coming to Adelaide Contemporary in 2020?).

But seriously – because the consequences of this problem are extremely serious – takeaway food packaging is a key offender in our country’s litter predicament. According to the Keep Australia Beautiful National Litter Index, South Australia’s litter levels increased in 2015 and ’16, despite a national trend toward reduction.

Rubbish in the street usually ends up in our waterways, adding to the already devastating amount of plastic debris polluting the world’s oceans. There, it will take between fifty and 500 years to break down, assuming Nemo doesn’t find it first…

But the Knight of Cups brings good news! The solution to this problem is relatively simple: don’t use takeaway cups (at the very least, please don’t use a lid).

Do Special Agent Dale Cooper proud and drink your coffee inside any one of Adelaide’s damn fine caffeinated establishments.

If you’re on the move, bring a reusable cup, like a KeepCup. Designed by café staff, these are the best options for the environment and for your barista, because KeepCups come in sizes that match their disposable cousins. My favourite caffeine dealer assures me that KeepCups are not considered a nuisance in ~the biz~. Just label it with your name and/or order to help keep the espresso (and thirsty queues) flowing.

Café owners could incentivise customers to use KeepCups by offering them a discount, and could stock some on the counter for sale. I hear Tell Henry’s due to receive a shipment of Star Wars KeepCups soon, for any Jedi Knight of Cups out there.

Sadly, biodegradable takeaway cups, like the familiar Biopak types, are not a foolproof solution. While they can be composted in a commercial facility, they won’t necessarily end up there. Without clear instructions on the cup, workers at waste processing plants don’t have the time to discern between recycled, recyclable, biodegradable or compostable materials. Real talk: your paper cup is all but guaranteed to end up in landfill.

What’s more, it could take a tonne of true recyclables with it. If polyethylene has potentially contaminated a load of reusable refuse, the whole lot ends up at the dump, regardless.

At the end of a fifteen-minute lifespan, five-hundred billion disposable coffee cups go to waste around the world each year. So, it’s probably about time to wake up and smell the KeepCup.