Re: theWatt Podcast 73

Hi Ben,

Of course you are right life cycle analysis is more complete than emissions by fuel, however i think that you place to much emphasis on the issue most vehicles will use the large majority of energy during their life rather than manufacture. I`ve seen figuers of 80% impact for fuel but recently heard people state >90%...it varies but lets not be to soft on hummers and their VAST resource usage at every stage.

Interestingly LCA also has problems, biofuels make this very clear. A typical LCA of a biofuel will calculate impact based on energy for fertiliser, pesticides, water pumping, sequestration of carbon into soil or erossion and compare this to output of energy. Sounds reasonable. But, another significant factor is land use competition and resultant deforestation, this is typically not included...its not part of a cycle its a one off factor as agricultural trends change but can be hugely significant.