Duncan Graham-Rowe, New Scientist 6 May 09;
Sending an email across the Atlantic Ocean does not burn any jet fuel, but the internet is not without its own, huge carbon footprint. One estimate suggests it takes a whopping 152 billion kilowatt-hours per year just to power the data centres that keep the net running. Add to that the energy used by all the computers and peripherals linked to it and the whole thing could be responsible for as much as 2 per cent of all human-made CO2 emissions, putting it on a par with the aviation industry.
The way we use our computers also has an impact. According to Google, the production of the electricity needed for a single internet search generates 200 milligrams of CO2. This may not sound much, but it adds up: 1000 searches produce the same CO2 emissions as an average European car travelling 1 kilometre. Worse, internet traffic is currently growing at around 50 per cent each year. According to the international environmental coalition The Climate Group, total emissions from computers will increase by 280 per cent, to the equivalent of 1.4 gigatonnes of CO2, by 2020.
If the IT industry continues with business as usual, there is no question that the internet's energy consumption will skyrocket, says Bill Weihl, Google's green-energy tsar. As a result, many organisations are turning to so-called green data centres which are far more efficient at cooling computers. At the same time, new computers are becoming more efficient. This has led to the energy needed to send each megabyte of data across the net to fall by about 30 per cent annually, says Jonathan Koomey, an energy expert at the Lawrence Berkeley National Laboratory in Oakland, California.
IBM says it is developing carbon-neutral data centres, using a novel form of water cooling which channels the heat given off by chips to provide warmth for nearby homes and offices. In a similar vein, Google has patented the idea of sea-based floating data centres which use wave motion as a power source, while cold water sucked up from the deep ocean could cool the computer chips.
The internet itself could help us to reduce our energy consumption. Video conferencing is just one example, says Koomey. "Moving electrons is always better than moving atoms," he says. What no one knows, however, is whether the technology has led to any significant reduction in travel, or whether uptake in video conferencing has actually increased our CO2 emissions.
