With the arrival of colder days, coffee shops fill with people warming up with an espresso, latte, or hot chocolate.

The local coffee shop has evolved into a place to hang out with friends, hold informal meetings, and do homework. Come any day and you’ll find several social circles doing basically the same thing - having a cup of coffee.

And yet, despite all of those positive aspects, something is wrong with this picture. In the corner, under the milk and cinnamon and sugar, lurks an overflowing trash can. You know how it happened: we stand in line right in front of the expensive mugs and coffee-makers, buy our coffee, drink it, and then throw the paper cup in the garbage.

Usually we don’t stop to think about our actions, especially at seven in the morning, but I’m asking you right now to think about this: why don’t we buy and use the mugs instead of paper cups?

Maybe it’s because mugs are more expensive at face value, they’re bulky, and they’re annoying to carry around. Perhaps teens feel too young or out of place to make such a purchase. Whoever you are, whatever the reason, I’d like to try to convince you to change your ways and start using a mug.

Starbucks, the nation’s largest coffee chain with 8,000 locations (L.A. Times) offers a 10-cent discount per drink to customers who bring in their own “commuter mugs,” and most if not all franchises will give customers ceramic mugs if they’re enjoying their coffee in the shop. You might have to ask, but you’ll keep a cup out of the trash.

On its website, Starbucks states that in its 2004 fiscal year, “customers used commuter mugs 15.1 million times, eliminating 655,000 pounds of paper waste from reaching landfills.” So, if you go to Starbucks twice a week with your own mug, in six months you will have saved quite a bit of paper and almost five dollars.

You don’t have to buy a Starbucks brand travel mug. Why not use your favorite, or have a different one for each day of the week? You can start a trend and carry them in polka-dotted handbags or clipped to carabiners, like Nalgene water bottles. As with grocery tote bags, if you make sure to leave a mug in the car, it will always be there when you make a coffee run. Don’t be shy - throw away your fears and save the world. No one can blame others for what they do or don’t do forever. Use a mug, save some money, and be proud to take an eco-friendly step.