Anyway I don't know where you're getting your figures from, but why exactly would a combination of cutting energy use, biofuels and green energy sources work?
Is there a not missing there ?
Biofuels do not make much a "profit" in energy, in the USA they have found that several of the pilot programmes actually used more energy than they produced. Once you add up the energy input from nitrate fertilisers, machinery etc, to the effort in converting it to a useful fuel, it's just not very good.
Genetic engineering may produce crops with higher yields, but we'd probably have to go for more radical options in getting the plant to produce chemicals more amenable to being burned.
Are you the sort of green that likes GM ?
There is a place for biofuels however in the leftovers from crops, but this is not a big thing.
I'm not sure what you mean by "insulation" ?
Most homes a relatively well insulated already, maybe you could 25% less heat consumed. To get any more the only way is to replace homes with more efficient ones. Home building is a huge consumer of energy, and simply waiting to repplace old houses at they reach the end of their lives is too slow to be useful.
But hell, lets just say I'm wrong about that, and imagine some awful green world where only the current level of public transport is used, and no private cars at all, and trains move by homeopathy.
I just don't see how we can reduce domestic consumption by more than 50%. What good is that ?
Also as a green I assume you have uncritical acceptence of the collapse of the Gulf Stream from climate change ?
That will push W. European and especially British energy consumption through the roof.
Thus I doubt there's any way we can insulate as fast as Britain cools.
Maybe it's worth insulating, but that's sandcastles in the tide.
Fact is that even without the global conveyer breaking, we know that historically harsh climate conditions happen more often than greens care to admit.
As for solar cells, part of my background is in the technology they are based upon, they are made with very similar processes to processor chips. They are horribly expensive to make, both financially and in energy. Useful for calculators, or in isolated areas where mains is not practical but not as mains.
Greens seem divided on windmills. In as much as I can work it out the view is that Greenpeace likes them, just so long is they can't be seen by their members. Actually what we have here is simply a superstitious fear of technology. Modern windmills are very techie, big white constructions of advanced composites and metal.
How many windmills do you think we need ?
The wind farm in Cumbria was state of the art, and they hoped that each unit would give "up to" 2 megawatts.
You wanted numbers...
British energy consupmtion is roughly 10^19 joules per year. (1 with 19 0's after it)
Thus you'd need
10^19/(2000000 24 365 60 60) ' seconds in a year = about 160,000 windmills.
That's assuming they work at peak efficiency all the time, I guess in reality you'd need rather closer to 200,000
With that density, there'd be few birds in Britain, and migratory birds for thousands of miles beyond would become extinct.
Assuing a 10 year life which is pretty good for a coimplex structure in windy conditions, you have to build 15-20,000 per year merely to keep them replaced.
Also of course they are pretty fragile things, and it's all too easy to see a fat tailed weather event taking out a large number. For security we might need as many as 25-30% more.
How many people would they kill ?
I can't find the Swedish figures on the web, but as you may know they have about the highest standards of worker safety in the world.
As I recall they were talking about roughly one worker per 100 windmill years. You can of course think up your own numbers. Just bear in mind that you are talking of big high structures under construction, that need a lot of repair work.
By necessity they are in windy places, which doesn't help.
I guess we're thus talking about something vaguely like 2- thousand people killed per year building and maintaining windmills.
In very round numbers wind costs about the same as nuclear in terms of capital costs and waste disposal. But has very much worse survivablity.
We would have to cut energy use by a lot, I agree, but that doesn't mean people will freeze to death. better insulation will help for a start.