There are two coffee mugs on my desk. Birthday presents. They've been co-opted as storage for pens, business cards and other office items. They've never been used for coffee. And research at Wageningen suggests that is an environmentally sound decision. Having your own coffee mug is not as environmentally friendly as everyone seems to think.
The study is actually about the 'bio cup' - is this receptacle (made of polylactic acid) more or less sustainable than its plastic counterpart or the paper beaker with a bio-layer? The answer grates: nope, the bio cup is not more sustainable. The disposable beaker makers eagerly twist that message round: plastic beakers are the most sustainable.
The conclusion from Wageningen is very much in line with earlier studies. Taking all the environmental indicators as a whole, plastic beakers do not actually do badly at all. Nevertheless, Wageningen UR wants to introduce the bio cup because of its image. A green institution that serves coffee in plastic beakers is clearly a difficult concept to deal with, whatever the facts of the matter may be.
Other interests are playing a part too behind the scenes. The bio cup for hot drinks was invented in Wageningen and it would be nice if there was a market for it here, starting with its own vending machines. And there's nothing wrong with that. The bio cup may be no more sustainable than the plastic one, but it's no worse. The Wageningen study into the beakers did not in fact declare a winner.
Even so, it will be a little while before the plastic beakers are retired. There are quite a number of hurdles yet before the bio cups can be introduced, the key one being that they are not yet on the market. Processing them is an issue too. According to the study, recycling is the most sustainable option, but that needs the cups to be collected separately. An initial test on the campus failed miserably. The special collection bins were removed when VIPs came visiting - those bins, they made it looked so messy...
Having your own mug does not necessarily make you an environmental barbarian, though. They do score more poorly than the plastic beakers if you wash them too often. But if you only do that once every five cups of coffee, the environmental picture becomes more favourable. Re-use is always better, incidentally - for the plastic ones too.