There continues to be much coverage in the press about the impact IT is having on the environment through increasing power consumption. As well as berating IT departments for the poor running of data centres and deploying devices inefficiently in the field there has also been more positive talk about the valuable role IT can play in reducing carbon emissions elsewhere, especially in transportation. This is a pressing issue anyway with the fuel price crisis.

Estimates vary in the total power used by IT, but as a percentage of total power consumption it is not necessarily bad if this increases, as long as emissions fall elsewhere as a result of innovative use of IT. If, say, 100 telepresence meetings can be run for the same equivalent carbon emissions as flying one person across the Atlantic, then this is almost certainly a more productive use of that power, however it is supplied.

The real problem comes with actually proving that investing in and increasing the use of electronic collaboration tools is really reducing actual travel. So when at its annual analyst conference this week Cisco made claims to this effect analysts were keen to know how this was measured.

In the absence of a generally agreed emissions accountancy method for business, financial measurements are the next best thing. Cisco's claim was that in the period of one year 120,000 telepresence meetings had taken place, reduced travel costs by $85 million. Now, if this figure is for real it will pay for an awful lot of communications equipment, so presumably the return on investment will be pretty good as well as the CSR (corporate social responsibility) message.

Gratifyingly, as a market leading supplier of network communication equipment, it seems Cisco is setting an example. Its estimated savings are based on a reduction in the average employee's travel expenses. With around 61,500 employees that is around $1,380 per head. That equates to between 1 and 10 flights per year depending on the route and class of travel or a few thousand kilometres claimed for car travel. Given that some employees will not travel much at all the actual reduction in for field employees must be somewhat higher than this.

As well as year over year comparisons on travel expenditure, Cisco has a double check on this figure. After every telepresence meeting the attendees are asked to complete a survey stating how the meeting would otherwise have been convened. This means that Cisco has more in depth data on the type of travel that is being replaced although it did not share this at the conference.

Demonstrating that IT really can reduce emissions elsewhere is good - but green wash is not. It is important that claims are backed by hard data, however for a full understanding it is necessary to know what the total travel spending is. Cisco has annual revenues approaching $40B and total travel costs are likely to be much, much higher than its $85 million saving (which is about 0.2% of revenue) and it also needs to take in to account non-employee travel - such as that of the few hundred analysts and consultants if flew to the UK to hear its message this week.