Yahoo! has announced its going to purchase 250,000 tonnes of carbon offsets, equivalent to its green house gas (GHG) emissions in 2006. Since the bulk of those will probably have come from its datacentre operations does this make carbon offsetting a valid strategy for datacentre operators in general.

After all, greening your datacentre is an investment and it could be that the RoI of carbon offsetting is much higher than the ROI of lowering power consumption in your datacentre; the upfront cost is possibly lower to begin with; the cost of each offset GHG tonne being lower than the cost of each directly reduced GHG tonne.

This could all be a thought of as a palpably silly suggestion as it depends on your view of carbon offsets - are they a viable way of reducing GHG emissions or not? - and your view of global warming.

However, by posing the question to various suppliers, interesting views are revealed.

Offsetting is greenwash

The extreme end of the spectrum of views about offsetting is that it is a form of cheating.

Here is Kelly Smith, the MD of Smartbunker: "The first category on the journey towards sustainable electrical generation is 'carbon offsetting'. That is, instead of reducing or eliminating the use of electricity generated from fossil fuels, the datacentre pays a third-party company to implement schemes, often in far-flung countries, designed to extract an equal amount of carbon from the environment. The classic example is tree planting, as trees absorb carbon."

"There have been very vocal doubts raised over carbon offsetting schemes. Once out of the ground and emitted into the atmosphere through the power station¹s chimney, fossil carbon joins the active carbon pool (the carbon in circulation before the fossil derived additions) and will not go back into the fossil carbon pool for many thousands of years."

"There is, even if tree-planting schemes are effective, more carbon in circulation than there would otherwise have been. As soon as the planted trees are cut down and burnt or simply die and rot, the captured fossil carbon is re-released. This carbon will, relevant to ourselves and our descendents, never be neutralised and it cannot in any meaningful way be offset."

Smith's conclusion is this: "Carbon offsetting schemes assuage guilt whilst allowing business-as-usual but are no answer and can be quite safely viewed as greenwash."

Jordan Gross, CEO of Ultraspeed, also thinks carbon offsets have no place: "Carbon offsets are not a solution to solving the problem currently at hand - the emission of an excessive amount of carbon into our atmosphere."

"Offsets are merely a distracting sidestep - and one that CIO's should not be distracted by. Time would be better spent on achieving real energy use reduction (and therefore carbon emission reduction)."

"It is important when looking to reduce carbon emissions that the whole picture is looked at - for example, there may be little point replacing perfectly good 1U servers with blades if the emissions generated during the production of the blades, and the destruction of the 1U servers will actually contribute more to the carbon footprint compared to the cost of keeping and running the original 1U servers - the big picture is important!

He asserts too that: "Suppliers fall under the same caption as the above - they need to reduce their energy emissions at source as well."

That's clear enough. A less extreme position asserts offsetting has no place in datacentres although it may be valid elsewhere.