Both sides of the argument

Column for Ethical Consumer magazine Jan-Feb 2009

The problem of sloppy thinking and research behind media coverage of green issues has been highlighted in this column before. False or meaningless facts often end up as “memes” that reproduce across the internet.

An interesting example concerns the energy used in paper manufacture.

There are all sorts of ways to reduce the environmental impact of computers. One of the most obvious is to avoid printing documents when you don’t really need to and to print on both sides of the paper when you do. Modern laser printers make this fairly straightforward.

At an event I attended recently one of the presenters gave a short talk to promote the idea of printing documents using both sides of the paper. He pointed out that it took “60 watts” of energy to manufacture a sheet of white A4 paper.

This makes no sense of course. As I pointed out to him afterwards (I’m like that), you measure energy in joules, not watts. It was meaningless to say it took 60 watts of energy to do anything, like saying that a road is 60 mph long. “Yes I know” he said, “but people don’t understand joules”. To which I might have said, why not tell them it takes 60 inches of energy, an even more friendly unit and equally meaningless.

When doing some research later I realised that the source of this 60 watts idea was a press release issued by the very highly-respected Palo Alto Research Centre (PARC) in California – inventors of the point-and-click graphical user interface we all use now to control our computers. They have come up with the idea of printer ink that disappears after a while. This apparently is a green breakthrough because it allows paper to be re-used rather than recycled (I have my doubts). In support of this, PARC said that it took 204,000 joules (roughly 60 watt-hours – hence the “60 watts”) to manufacture a piece of white paper from virgin pulp, much more than is required to print it. If you Google “204,000 joules” you’ll find this particular factoid spread right across the net, as more and more news sites picked up on the story.

Well, at least they got the units right. The problem is the number. A large paper manufacturing machine is capable of producing a continuous sheet of paper 10 metres wide moving at roughly 100 km/hour. At 204,000 joules per A4 sheet such a machine would consume almost a gigawatt of power - around 2.5% of the UK’s total electricity consumption. That simply cannot be right.

It’s a shame because the core point – that it takes a lot more energy to manufacture (or recycle) a piece of paper than to print on it – is correct and one good reason why we should print less documents, and print on both sides when we do.