You said, "nothing can now stop Global Warming and Over Population from having a catastrophic effect on our planet during the next 20 years."
I'm a little confused by that. Last I saw, the science is uncertain as to whether we've already passed the point of no return, but that the general consensus was that we are not. I would have thought we'd have heard something by now if we really had passed that point. Did I misunderstand you?
If we could be sure that we had already passed the point of no return - then there would be no point in combatting it. We would just have to wait for the famines to hit - and no doubt protect our own interests and let the vulnerable starve. We would have to fight for the remaining resources, and fight I am sure we would.
The Stern report in 2007 suggested that we are not yet past the point of no return. It also suggested that even for the rich - reducing emissions would be significantly cheaper than dealing with the consequences of global warming.
You mention overpopulation. It's undoubtedly an issue, but I'm not convinced it's the greatest issue. Already, as uncomfortable as it is for us to read - most people in the western world are consuming far more than their (our!) fair share of the world's resources. I seem to remember that a child in the USA uses as much in terms of resources as 200 Indian children. Is 3rd world overpopulation the biggest problem here?
Bear in mind also - there is little understanding of just WHY people in poorer countries have so many children. Over here, we have a welfare state, most of us have a pension. Few (if any) poor countries have any such welfare state or pension provision. They need their children to look after them.
There is also the issue of high infant mortality. Already these people need somebody to look after them in their old age, but unless they have a lot of children, it's likely that they won't have any to survive into adulthood.
Quite apart from the lack of basic education about contraception.
You're right that we deal with things too little, too late. It's a classic "catch 22". Whilst the effects of climate change and loss of resources are not yet devastating, lack of action becomes easier - action is harder because there are other more immediate problems to deal with. Once the consequences of climate change and lack of resources begin to bite - it may be too late to prevent the worst things happening. same goes for resources, be it fuel for transport, or for heating our homes.. etc
Politicians continue to fiddle and play party politics, but then - what else can they do? Dealing with these problems now means pain in the short-term. Pain in the short-term = you get voted out. Hardly surprising that politicians are concerned only with issues that will bite during the 5 years of their own parliament. Let the next government take the blame for our inaction...
For that - the electorate need to be more aware of the issues. Then the politicians might be able to act.
BTW - I *HIGHLY* recommend the course that goes with these books:
http://www.amazon.co.uk/Warming-World-D-Humphreys/dp/0749216360/ref=sr_1_11?ie=UTF8&qid=1312499055&sr=8-11
http://www.amazon.co.uk/Environmental-Issues-Responses-W-Brown/dp/0749216379/ref=sr_1_1?s=books&ie=UTF8&qid=1312499187&sr=1-1
http://www.amazon.co.uk/Prospects-Possibilities-P-Jehlicka/dp/0749216387/ref=sr_1_1?s=books&ie=UTF8&qid=1312499217&sr=1-1
Even if you don't take the course - the books are well worth a read.
More locally - I certainly agree that we urgently need to address the skills shortage. We need to become more self sufficient, I firmly believe that we should be investing in technology and agriculture. We need to shift our economy towards products that will increasingly be needed in the world (in this case food and energy) so that our supplies are secure for as long as possible, minimising negative effects wherever we can.
"So our prospects are for a steady increase in unemployment and a relatively rapid decline in wealth."
Unless we deal with it that's exactly what we're looking at - yet the electorate are notoriously short-sighted. A "want it now" culture is very prominent.
ETA: Edited above for clarity. (thanks for the compliment btw) See Skellington's post for remainder of my answer.