There is a tendency to obsess on "which direction" the climate might be headed when it would seem to me the core issue is that:
"All forms of Climate Change will increase stress."
The ways that mankind deals with stress are:
1) Improve efficiency (relieving stress)
2) War (reduces the population, thus reducing stress)
3) Natural Causes (disease)
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I'm sure we can think of more and dig deeper into these.
Ignore "which direction" things change. Many models suggest weather might change by region anyway, so the issue going forward is more about stress.
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Let me start with efficiency...
The rise of human population coincided with vast efficiency improvements in man's ability to perpetuate itself.
The computer gave us the last "surge" of potential gains, but that's starting to wear out.
One wonders if humanity can rely on efficiency gains forever?
I tend to be skeptical. Unfortunately this means that "efficiency" cannot be our solution.
(that's bad news)
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Thanksgiving Day
There's a moral in this holiday...
When the colony was first formed back in the 1600's the settlers were practicing a "communial" system. All things were shared equally. Unfortunately this type of system has been shown to be "less efficient" because when everything is shared people tend to wait for others to do the work.
The settlers almost starved to death.
This was caused by the "Tragedy of the Commons" where communial living leads to lower productivity and neglect of shared things.
http://en.m.wikipedia.org/wiki/Tragedy_of_the_commons
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The colonists were christians and of a Protestant background. The "Protestant Work Ethic" said that:
"People should have the ability to enjoy the fruits of their labors."
After applying these new principles and rejecting the "communial" habits the colonist saw a big increase in efficiency and they began generating a surplus of food. It was at the point where success was assured with this new system that the colonists invited their native neighbors to celebrate a feast.
It actually wasn't recognized as a holiday until centuries later.
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The moral of Thanksgiving Day is that high efficiency systems (Protestant Work Ethic) can generate a surplus of wealth and this then drives the growth of human population.
The "anti-message" is that if you want to REDUCE human population then you adopt less efficient systems.
A great example was China in the 1970's. They adopted communistic principles and as a result millions of Chinese starved to death because the system worked so poorly.
The question related to "stress" is what outcome do we want?
More population growth can be seen as a bad thing... so "inefficient" philosophies are gaining favor, but "stress" must rise as a result.
Thanksgiving is a holiday that celebrated our "growth" period in history.
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China
China is a great example to look at.
As said above, when "low efficiency" systems were applied back in the 1970's millions of chinese starved as the central government was oblivious to problems.
But the chinese learned.
New leadership came in and they began implementing "Protestant Work Ethic" principles. One rather interesting fact is that the Protestant religion (once banned by the Communists) is now growing within China.
So China adopts "efficiency" and now they are growing...
But... there's a catch... they are now polluting.
China now produces FIVE times more CO2 than any other single country.
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Many who are liberal / socialists are unhappy that China abandoned their communist ways in favor of growth.
We can define a sort of equation:
"Efficient Systems" (Protestant Work Ethic) produce wealth and a growing population and have lower stress.
"In-efficient Systems" (Communist / Socialist) reduce wealth, halt population growth, but increase stress.
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Climate changes also cause stress. If any country begins with "Efficient Systems" their wealth will grow, their population will grow, and eventually they will reach a sort of maximum based on resources available. If at this point either a climate change or a switch to "In-efficient Systems" you will place stress on the society.
...so in a way one becomes "a victim of their own success".
Communism holds the promise of perpetual failure to grow... which in a strange way is a "good thing".
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This also means that China cannot grow forever.
The Protestant Work Ethic can make a nation prosperous, but it has a sort of end when there is no more capability to expand anymore.
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So I want to simply this a little...
The typical "cycle of civilization" goes:
1) Favorable climate conditions combined with "Efficient Systems" creates wealth and human population growth.
2) Years of success cause a civilization to "plateau" which drives political systems towards "In-efficient Systems" in a misguided attempt to improve conditions.
3) The consequences of "In-efficient Systems" combined with overpopulation cause stress.
4) Unfavorable Climate Change during this later period of civilization causes more stress than if "Efficient Systems" were in place or if the population were smaller.
5) It is the combination of these forces than amplify the negative outlook.
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The stress of climate change is only one of multiple stress factors.