While a caffeinated workforce is generally a happy one, it may not be an efficient one — at least, not from a planetary point of view, according to the German city of Hamburg. As part of a wider effort to reduce waste and energy consumption, Hamburg has banned the use of coffee pods in government-run buildings, offices and institutions like schools and universities.

Love them or hate them, single-use coffee capsules are a quick way to brew a reasonable cup of coffee, and Germans use roughly 3 billion pods a year. But Hamburg's Department for the Environment and Energy argues that coffee pods cause "unnecessary resource consumption and waste generation," and "often contain polluting aluminum."

Coffee pods are just one of a variety of products city employees are no longer allowed to use on office premises. Mandatory green guidelines now prohibit taxpayers' money from being spent on nonrefillable plastic bottles, plastic cutlery, plates and cups, chlorine-based cleaning products, air freshener and patio heaters.

Hamburg is believed to be the world's first city to ban coffee pods. Jan Kerstan, Hamburg's environment senator, who announced the move to promote sustainable procurement, says the city wants to encourage businesses and private individuals to accept greater accountability for their purchasing decisions. "Our objective is to increase the share of environmentally friendly products significantly, in order to help combat climate change," Kerstan argues.

And single-use coffee pods have been in the cross hairs of environmentalists. Some, like Keurig's K-Cups, are not recyclable (Keurig aims for 100 percent recyclability by 2020). Others are recyclable, but that doesn't ensure that those convenient little pods actually end up sorted with the plastic and glass — not tossed in the trash bin — after you've prepared your morning cup of Joe.

Nespresso, Europe's most popular pod provider — whose spokesman is the equally popular George Clooney — says it has 14,000 capsule collection points worldwide, with the capacity, at least, to recycle over 80 percent of all used capsules. The company aims to raise this to 100 percent by 2020.

In Germany, where municipal recycling amenities are widespread and long-established, Nespresso stresses that its almost entirely aluminum pods can be placed into the ubiquitous yellow bins in the backyard.

Nespresso told us that many of its pods end up at aluminum plants for reuse, together with the rest of Germany's domestic aluminum waste, such as food and drink cans. But the company wasn't able to confirm what percentage of used pods were actually recycled, either in Germany or elsewhere.

Jan Dube, spokesman for the Hamburg Department of the Environment and Energy, told us that, to his knowledge, "most of the capsules can't be recycled easily, because they are often made of a mixture of plastic and aluminum," Dube says.

Nespresso says it was surprised by Hamburg's decision. The company insists that "portioned coffee makes sense, both economically and in terms of sustainability." Nespresso argues that reducing the amount of coffee and water used per cup has a bigger impact on carbon footprint than packaging — especially packaging made from aluminum.

Mindful of growing consumer awareness of pod waste, the Italian coffee brand Lavazza has developed a "compostable capsule": It's made from biodegradable organic materials that the company aims to turn into agricultural fertilizer. Whether that's enough to lure connoisseurs of Italian coffee made in traditional espresso machines remains to be seen.

In Hamburg, at least, the authorities have already made up their minds. Jan Dube says they simply cannot justify buying "6 grams of coffee wrapped in 3 grams of packaging" with taxpayer money. The city aims to cut down on packaging waste in general — whether it can be recycled or not.

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