I often go out of my way to be eco-friendly: I always remember my reusable shopping bags, I sort my own recyclables, and I even refuse to buy makeup products that include environmentally (and dermatologically) deleterious chemicals like parabens. So, when I realized that our only two payment options — paper cash or plastic cards — come from environmentally dubious materials, I absolutely flipped. Which should I choose to make sure I am being as green as possible?

Pros and Cons: Cash

The concept of cash has been contentious for centuries, long before environmental preservation was even a consideration for most Americans. In fact, the Founding Fathers were largely opposed to the printing of federal paper currency because the cash they printed during the Revolutionary War became absolutely worthless before the United States was even truly free. Through the years, cash became less and less valuable in comparison to the gold and silver to which the paper money was linked, and today, the dollar isn’t backed at all by any inherently precious material. Thus, the paper dollar in your wallet is only symbolically valuable.

Still, the history of American paper money does little to help us understand cash’s impact on the environment. The truth is that paper money is surprisingly resource-heavy, requiring abundant cotton and linen in addition to the land, water, pesticides, fertilizers, and other supplies necessary to tend those crops. Unfortunately, cotton is notoriously unfriendly to the environment; it is estimated that cultivating, harvesting, and ginning a single kilogram of cotton is as energy-intensive as producing the same quantity of plastic. Even worse, metal coins are especially excruciating, as mining for copper, zinc, and nickel is well-known to decimate natural environments. Plus, the energy that goes into refining and smelting the metal is nearly double that of a comparable amount of plastic.

On top of this, most paper money doesn’t last more than 16 months of circulation — and that circulation adds to the unfortunate energy footprint of our paper and metal currency. Bills and coins must travel between and among the Federal Reserve, banks, and merchants, racking up millions of miles during their meager lifespans. Meanwhile, credit cards stay planted right in your pocket.

Pros and Cons: Credit

Credit cards of every type, from platinum rewards to pre-paid, are usually made out of a type of plastic called polyvinyl chloride, or PVC. As most people know, all plastic comes initially from crude oil, which is siphoned from below Earth’s surface in a variety of dubious methods. Through various chemical processes, scientists can transfigure that oil into the credit cards you find in your wallet, at a rate of about 4.25 grams of petroleum per 5-gram card. At last estimate, there are roughly 1.6 billion credit, debit, and ATM cards floating around the United States, which means it takes at least 45,000 barrels of oil per year to fashion enough cards to supply our demand. Worse, most curbside recycling programs refuse to take items made with PVC because the plastic produces toxins when incinerated.

Yet, there is some hope for the eco-lover who prefers plastic payment. For one, many credit card companies are already experimenting with greener materials, like biopolymers and compostable PVC, to cut back on the environmental costs. For another, credit cards last much longer than paper money: It takes more than eight years for the plastic to start breaking down — though we usually cut them up after they expire, between two to four years after creation.

Additionally, credit cards offer environmentalists a number of green perks that they can use to improve nature while making everyday expenditures.  Any cash-back earned from rewards cards can go straight to eco-charities, while other general rewards cards can provide discounts on green purchases. Plus, there are a handful of automatically eco-friendly credit cards, including:

• Credo. With every purchase, Comenity Bank donates 10 cents to a rotating group of nonprofits whose aims include environmental sustainability, world peace, and social justice.
• Sustain: Green MasterCard. Sustain: Green will purchase and offset two pounds of carbon for every dollar you spend, with additional carbon elimination for additional spending.
• Green America Visa Platinum. Green America accepts a percentage of every purchase made with this card to support its environmental, social and economic justice programs.

Of course, there are a number of ways to transform regular credit cards into green ones, like by eschewing monthly paper statements in favor of digital copies. The fewer natural resources you consume, the better the payment option becomes.

The Winner

While I rarely fall in favor of any practice that relies on fossil fuels, it seems obvious that credit cards boast more environmental properties than cash — though I doubt I’ll be completely purging my pocketbook of paper money any time soon.