I see another report has come out casting doubt over the value of biofuels as carbon savers.  This one points out that previous estimates of greenhouse gas savings have underestimated the contribution of nitrous oxide emissions from fertiliser uses in the calculations.

Since nitrous oxide is 270-300 times as potent a greenhouse gas as carbon dioxide we probably don't want to chuck too much of it into the atmosphere (and although its concentrations are rising it isn't the main problem - but is still a problem!).  And yet the use of inorganic nitrogenous fertilisers is one massive source of nitrous oxide in the atmosphere. 

So not only are biofuels highly variable in how much carbon dioxide they might save, and not only does the growing of biofuels displace food production into places which are currently carbon stores resulting in carbon release, but fertiliser use further reduces the value of biofuel savings.  And that's just the carbon accounting!  Throw in reduced food production, increased food prices and further biodiversity loss and it is very very difficult to see why anyone who isn't going to make money out of them would stand up for biofuels.

I object to the fact that every time I fill my car with diesel (which I obviously do as rarely as possible) I am putting some biodiesel in too - and that may well have brought extinction closer for the tiger and thousands of other species.

Anonymous