Former President Reagan defined a recession as when your friend lost his job, and a depression as when you lost your job. Collapse is when no one has a job; in fact there are no longer any such things as jobs to be had.
Various types of doomers/collapsitarians/dystopians:
* Luddites, anarchists, and anti-civilization activists who are trying the hasten collapse as soon as possible.
* Survivalists: collapse as the penalty for modern liberalism.
* Radical environmentalists who see ecological and environmental collapse
* Anti-globalists who see collapse as the penalty for globalism.
* Anti-Americans rooting for collapse of America and developed world
* Financial doomers: who see the never ending Depression
* Peak Everythingers who see all resources running out
Die off scenarios are at dieoff.org
Plenty of other places online describing these scenarios of decline, war, and collapse to 0 to 2 billion people starting as early as this year and usually by 2025 but no later than 2100.
One thing of note is that most people usually think that Hitler and Stalin were bad guys for killing or causing the death of about 100 million people. Most of the civilization die off scenarios are that level of death each and every year for 70 years. 1000 times the number of deaths in the holocaust. Why is there the belief that significant mitigation efforts would not be made ?
Why it Won't Happen
1. Efficiency, conservation and an energy plans can be enhanced beyond current levels with minimal strain. There has been partially voluntary reductions in energy demand during the credit crisis. 10% reductions with minimal effort and 20% reductions with more austerity.
2. Rationing of food, fuel and clothes was successfully maintained in many countries during World War 2. Any resource decline or environmental situation can have governments use rationing to buy time for a transition.
The UK had stricter rationing than the USA during and after the war.
Thus it shows that oil and food supplies can be greatly reduced while maintaining a war-level mobilization.
90% reductions can be handled in this way and possibly more.
3. Some simple and rapid transitions are possible. Ban or confiscate large gas guzzling vehicles and only allow light weight all electric or super-efficient vehicles other than freight trucks and heavy delivery trucks. In less than one year a mobilized effort with shifts in the weight of vehicles permitted and loosened safety and bureaucratic regulations to speed the changes.
4. Rapid switchover for the electricity generation infrastructure. A war-time level mobilized switchover for electricity generation could be achieved quickly. Lift regulatory restrictions on nuclear power. Weld together containment domes to get around production limitations on large forgings. Use the staff of coal plants for the new nuclear plants. The staff of early nuclear plants did come from the coal plants. Nuclear staffing levels were 200 or less originally.
5. In regards to global warming and environmental concerns:
* a rapid switchover to totally clean power would stop the air pollution of coal and most oil and would greatly reduce any additional CO2
* geoengineering can be used to reduce global temperatures if necessary
* if the beliefs of climate change being from man-made sources are right then we are already geoengineering by accident as a side effect of our industry. It will be cheaper and easier to geoengineer to cancel those accidental side effects with intentional reversal efforts
6. A real space age can be started right away with technology that we already have.
7. If there was a global war over resources. There would be clear winners. In all out war there would be clear losers. The US would not lose.
8. There is plenty of technology now and a lot more that will be available soon to innovate away doomer scenarios.
* biofuels and synthetic fuels are already at about 10% of total fuel levels. If there was a need to replace all oil tomorrow a combination of world war 2 level rationing and biofuels and synthetics would be sufficient (Germany invented to coal to liquid fuel technology back in World War 2.)
* There are significant levels of hydroelectric, wind, and nuclear power
* If any of the challenges can be staved off for ten years or so there will be significant transitions to new technology (electric and hybrid vehicles) and the availability of more new technology
9. Financial doom scenarios
* Mandated resets of debt forgiveness, re-issuing script etc... can be used to reboot a country or a financial system
* People and systems for production would still exist even if there was 1000 trillion in debt
10. All out nuclear war would kill less than 50% of the population. Current nuclear arsenals are reduced by ten times from the peak.
There are valid extinction risks and scenarios with several listed and discussed at the Lifeboat Foundation.
Generally the extinction effects have to be so rapid that their is no time to mitigate or adapt. Space based phenomena like massive asteroid or a nearby gamma ray burster are the kind of situation that we currently could not handle. This is why there is need to stop pissing around with penny ante crap and get serious about moving civilization to full Kardashev level II. At that level there is no known threat other than all out super-war that would be a risk to such a civilization. Even things like the sun going nova could be detected and handled as such a civilization would have its own highly efficient nuclear fusion and other power sources.
Gary Jones on Collapsitarians and this sites view on blackswans.