Some socio-economic questions are so complex that they are probably impossible to definitively answer, since we only have one planet to work with and one human history unfolding. We can’t run a bunch of trials and work out the probabilities involved (sweet, sweet Monte Carlo method). At the moment, one such question is: “What would happen geopolitically if economic growth in China really slowed down for a while?”
The question relates to how quickly China should deploy renewable energy, to help respond to climate change.
One can imagine a benign scenario where growth slows a bit while China focuses on greenery, the air in Beijing gets cleaner for a span longer than the Olympics, and China’s importance within the global system continues to increase smoothly (though how benign that increase is is another question).
One can also imagine a less benign scenario where the Chinese economy isn’t producing enough jobs to employ the generation entering the workforce. Without jobs, they could focus in large numbers on more destabilizing things, like overthrowing the Communist Party and establishing a more credible democracy (though what the many considerations involved in any such matter would be is another question, as well).
All told, the state of the global economy now seems pretty worrying. The immediate financial crisis was staved away with giant amounts of public money. But not much actual reform seems to have taken place in the financial system. At the same time, the European Union is dealing with a crisis and Japan continues to stagnate. If you believe that growth is generally good (though greenhouse gas pollution must fall), you have good reason to worry about the state of the world economy today. Alternatively, the same is true if you think growth is generally good for global stability, and global stability is important (World Wars are nasty things).