From Envirowiki

[edit] hrrm

The source data for these calculations is extremely iffy. While the calculations might be close to accurate on average, across a number of different products (In the same way that GDP is only accurate as an average of the population), for each individual product the results may be well over or under the actual reality. Of course, this is noted, but not very clearly. Perhaps the whole guesstimate should come under it's own heading, and be clearly labelled as sometimes inaccurate.

Also, mediawiki has a table format built in. It's not very simple, but at least it lets people copy figures for external use. See Help:Tables --Naught101 02:53, 12 August 2008 (UTC)

[edit] agreed but still better than guessing

I can only agree that this is iffy. However normally individuals are not in a position to do CO2 audits of complex systems. It is a sanity check which enables one to refute or confirm claims. If you search you will find claims that Wind will never pay back the CO2 produced and also that Wind is the best renewable option! I tried to do my own best guess.