Originally Posted by
JDNSW
Aluminium takes a lot more energy to produce from raw materials than does steel - but not only does recycling aluminium take a lot less energy than does recycling steel, but a far larger proportion of aluminium is actually recycled.
As with any "dust to dust" energy or emissions calculation, there are many assumptions required in the calculation, and what is assumed has a major influence on the result. Consequently, almost all such calculations have the assumptions made adjusted to achieve the desired result. And you can just about guarantee that none apply to any specific example.
Taking your suggestion in the first paragraph - if I trade my County on a new Puma, I probably achieve about a 10% decrease in carbon emissions compared to the Isuzu. This is offset to some extent by the extra mileage needed to take it to a dealer for service instead of doing it myself. For the manufacturing emissions to drop as low as those for the County, I would need to keep it for a similar length of time (24 years), and I seriously doubt that it will be maintainable that long due to parts shortages. As far as I can see, from a carbon emissions pointFSDA of view, I would do better to continue with the County.
Similarly, only more so, for the 2a ute. While it emits a lot more carbon per kilometre than a new Puma, it only does about 5,000km/year, so the payback time would correspondingly be longer, even taking the increase per kilometre into account. And to bring the per kilometre manufacturing carbon cost down to the same the Puma would have to last 40 years - which seems a bit unlikely (and anyway by then I would be well over 100, and unlikely to be driving)
John