Intuitively, it seems that the move from paper to digital forms of publishing should be good for the environment. Going paperless means trees don’t have to be cut down. No energy needs to be expended in making paper and ink and running the printing presses. No warehousing or shipping or powering of the retail outlets that sell the final product. Just a click and it appears on screen

On the other hand, storing the vast amounts of data that people want to have instant access to also consumes a lot of energy. And at face value it does. Just look at these figures for the estimated energy use by the data centres operated by the likes of Google, Facebook and Apple.

But these data centres service billions of people. Data centre operators also often choose locations where the electricity supply is from low-carbon sources. And many operators offset their emissions and are big investors in renewable energy.

In the case of Google, this means that their carbon footprint equates to about 8 grams of CO2 per day per user.

Which isn’t much. Just boiling the water for a cup of black tea or coffee generates 21g of CO2. Go for a large latte and that rises to 340g (burping cows and all that).

In any case, the carbon emissions associated with data centres are dwarfed by those generated by your modem and, of course, your computer. Computer scientist Neil Hunt estimated that just 20% of his online carbon footprint was associated with central data storage and downloads. The rest came from the “last mile” of his internet connection and his hardware. Even then, the total emissions came to 20 kg per month, or just 1% of his total carbon footprint.

So stay online. And if you want to exorcise that last bit of guilt, Hunt suggests dropping the meat from just one meal a week to make up for it.

Image: Håkan Dahlström via flickr