Carol, I wasn't suggesting we ignore the plastics and stuff completely - it's just that to get a total-impact cost of an item is seriously bloody hard! Focussing on one major point is just somewhere to start, since I don't have the whole week free to research this. :-) I've not heard about using hemp for plastics, that sounds interesting.

You're right about the renewable energy (actually not renewable, but it's from a source which isn't going to run out for a few million years yet :-) but that has drawbacks too. The 4 main renewable options are hydro, wind, sun and wave. Hydro requires large areas to be flooded, and the fluctuations in water level mean that birds and animals can't live there (as the level rises, the nests get flooded), plus farmers downstream get their water supplies cut off. Wind requires sodding huge turbines, which are unsightly and noisy, and the effects of the blades on birds and the low-frequency vibration on animals are not yet known. Sun requires large areas for the solar panels, and sunny areas too, which isn't much good in the UK! And wave power requires big unsightly barriers to be created which would block boats and could have an effect on sift deposition.

Apart from these drawbacks, there's also the impact of _creating_ the facilities for these. Hydro requires concrete dams, which requires some limestone area somewhere to be strip-mined, plus lots of complex machinery (metals and plastics). Wind, you need big turbines (metal and plastic). Sun, solar panels are very energy-intensive to produce, requiring metals, plastics, and lots of _seriously_ nasty chemicals. And waves, we're on metal and plastic for the barrier again. All this involves some serious impact on resources. I seem to remember that solar panels used to be a net energy _loss_ due to the energy effort involved in making them but I may be wrong, and the improvements in silicon technology probably means this isn't the case any more. Older solar technology uses mirrors to focus the heat to boil water and drive a turbine.

Kim, certainly the smaller the engine the better - I've no arguments with you on this at all. A V6 in a normal-sized car is rather excessive unless you want it as a sports car. SUVs still have the problems of more inefficient tyres and higher air resistance, though. Incidentally, I'm not trying to get at you personally - this is just a general observation on the state of SUVs. Oh, and I've seen your picture in the photo list - how much better looks to they want? ;-)

Wdyat, hydrogen fusion is still on the go, but it's a long way off being a practical electricity-generating proposition. It requires enormous investment in the hardware to do it, which rather limits how fast it can advance. Nuclear fission got its investment by being a step to nuclear weapons, but fusion isn't and so can't get any of the military-industrial money.

Graham.