Saturday, October 25, 2008


A recurrent, if lonely, theme in the Review has been this: if you want to save energy, stop moving around so damn much. For example, cities might have neighborhood conference centers where staffers working at home could meet via video with other employees of a firm. Or companies might downgrade the use of unimportant meetings. This has not been a topic of much interest in the environmental movement, which is far more concerned with improved miles per gallon, and so there has not been a lot of research. The following is a rare and important exception.

Scientific Blogging - At a recent "Informatics Day at the Technopark Zurich," a Microsoft booth allowed visitors were able to test how much CO2 they would save, if any, if they replaced a "real" meeting with a videoconference. . .

Example: The management of an international company is planning to hold a one-hour board meeting in Zurich, to take part in which one director must travel from London. The management would like to know which option is more environmentally friendly - a teleconference over the internet or traveling by car, train or aircraft to be physically present at the meeting. Is the difference really significant?

This is the basic hypothetical scenario which Empa scientist Roland Hischier, of the institution's Technology and Society Laboratory, has analyzed. . .

Microsoft provided Hirschier with a list of all the equipment which would be necessary to arrange the videoconference, such as laptop computers, video cameras, projectors, servers, routers and so on - together with details of their power consumption and other technical data such as transmission rate and necessary cooling capacity. Using this information alongside the "ecoinvent" data relating to the electronics equipment, power production, and the various travel options available, the Empa expert was able to calculate the resulting emissions of greenhouse gases, measured in CO2 equivalents. . .

The results painted a clear picture. The most important factor in a real journey is the energy consumed by the means of transport, i.e. the train, car or plane. This is responsible for more than 99.8 per cent of the environmental impact, regardless of how one travels. However, a video conference over the internet also consumes large amounts of electricity, for serves, routers, laptop computers and projectors all need to be powered up and some devices need to be cooled too. Together, they are responsible for about 95 per cent of the greenhouse gas emissions associated with this option.

Nevertheless, the two different scenarios considered differ decisively in the quantity of greenhouse gas emissions generated. The virtual meeting emerged with the best marks by far, producing a mere 20 kilograms of CO2 equivalent. . . The most favorable travel option, by rail (in this case taking a high speed train via Paris) causes 108 kilograms, about a five-fold increase. Travel by air or road increases equivalent CO2 emissions to 315 and 373 kilograms respectively, a 16 to 18-fold increase over the virtual meeting.

Hirschier also calculated how the distance traveled affects the result. In other words, over what distance is a "real" meeting still acceptable or even better than a virtual meeting in terms of environmental impact? The results were surprising; for distances of less than 200 kilometers he found that it is environmentally less damaging when a single participant travels to the meeting by train than organizing a videoconference.

"This is only true, however, when a single person has to travel this distance," says Hirschier. If two persons need to travel to the meeting then the distance is halved, to 100 kilometers. And, of course, if ten or more participants were to travel to a meeting, as is frequently the case with conferences and seminars, then a virtual meeting is many times more environmentally friendly than a real one.

This is the same result as that arrived at by an older investigation, in which Hischier, together with Lorenz Hilty, the head of Empa's Technology and Society Laboratory, calculated the environmental impact of the International Environmental Informatics Symposium in Zurich, which they themselves organized. The study demonstrated that transporting the over 300 conference participants to and from the event was responsible for more than 96 per cent of the environmental effects. Particularly striking was the fact that nearly two thirds of the environmental impact was caused just 6 per cent of the travelers - those who journeyed more than 8000 kilometers. In comparison, a completely virtual conference would have caused about 45 times less impact, according to calculations based on the Empa scientist's model.

Because personal contact is an important factor at meetings and conferences, and because it is the delegates' intercontinental flights which cause the greatest environmental impact, Hischier and Hilty evaluated the effect of a third option, a conference held in various different locations in parallel, in this case Zurich, Dallas und Tokyo. This approach caused the impact to be almost halved. Hilty plans to employ this trick next year during the organization of the R'09 Twin World Congress on Resource Management and Technology for Material and Energy Efficiency. This event will once again be arranged by Empa and the Swiss Academy of Engineering Sciences to take place in Davos, Switzerland, and also simultaneously in Nagoya, Japan, with, of course, live video transmissions between the two venues. "As a little project on the side, we also plan to investigate how easy the participants find using the new technology, and how much CO2 we save with the new arrangement," says Hilti.