Digital newspapers have gained an increasing amount of ground and from an environmental perspective have been put forward as a better alternative to paper-based newspapers. And many people would probably be prepared to agree – electronics must be more environmentally friendly, after all it just uses "a bit of electricity". But if you factor in manufacturing the computer, producing the energy needed to run it, and recycling, things are not quite as clear cut.

To analyse the climate impact of a newspaper, you start out from a lifecycle approach. This includes obtaining and transporting raw materials, producing the paper, printing, editing and distribution. For example, an annual subscription to a daily paper means 12 kilos in carbon dioxide emissions. This can be compared with driving from Stockholm to Göteborg, which produces carbon dioxide emissions of 120 kilos. Or a return flight to Mallorca which generates 730 kilos of carbon dioxide. It is also important to calculate how many people will read a particular copy of the paper newspaper. The more people who read the same copy, the lower the environmental impact.

The greatest environmental impact from printed newspapers is in the paper manufacturing process. At the same time, the paper industry is working hard to achieve high forest productivity and to cut emissions. The general rule is for three new trees to be planted for every one cut down. In 2009 there were a total of 460 000 tonnes of newspapers on the market in Sweden. 420 000 tonnes were sent for recycling. This corresponds to a collection rate of 91 per cent. The collected newspapers are returned to paper mills where the ink is removed before they are ground down into recovered fibre pulp used in new newspapers. Using recycled newspapers produces an energy saving of 70 per cent compared with producing newspapers from new pulp.

Producing the computers of today demands large amounts of plastic derived from crude oil. A computer also contains heavy metals and brominated flame retardants. As private individuals and companies are increasingly buying new computers and throwing away their old ones, the lifecycle for computers is getting shorter all the time, with a marked increase in the amount of waste. This means it is important that all electronic equipment is sent for recycling so that toxic substances that have a negative impact on the environment are not emitted. However, separating out the different parts of a computer is a complicated process.

Although many people might think that reading online just uses "a bit of electricity", digital newspaper reading does contribute towards carbon dioxide emissions. To produce these figures you include the carbon dioxide emissions that arise when the parts of the computer are manufactured, when the energy needed to run the computer is produced, when transporting the computer and for the editorial work. And while it is true that carbon dioxide emissions can be reduced by reading online, it obviously depends on how much time is spent in front of the screen. Half an hour reading online a day emits roughly the same amount of carbon dioxide as reading a daily paper – based on the newspaper being read by 2.4 people, which is the average. (Source: Holmen Paper Group)