Global warming will never be a serious issue. Even if it does become one, we already have many great solutions to solving it. In the case of medium effects, solutions can be quite easy and cheap - painting the roofs of buildings in cities white, changing the colour of the asphalt roads to a slightly brighter color, and planting trees throughout cities, can reduce city temperatures by 4-5C in cities... more than enough to cover most estimations of temperature increase.
We'll never have a fossil fuel-related global catastrophe. Despite what people are led to believe, we are not running out at any kind of massive rate. Indeed, global proved reserves of oil continue to grow at a faster rate than what we're consuming the stuff. We've already begun phasing out fossil fuels in many aspects of our lives... even if it takes another 50 years, we'll be fine.
There will be no major conflicts between China and the USA. China is not the USSR. China is capitalist. China depends on the USA (and the rest of the West) to survive, and the West depends on China. Both China and the USA are too interlinked to even consider warfare.
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Now that I've told you what WON'T be happening, now for some of my predictions of what will happen:
- The current financial crisis will ultimately result in the return to hard money, (that is, currency backed by some form of hard value store - like the gold standard of old), first, however, we will have long periods of austerity and inflation (for the most part of this decade). What these hard currencies will ultimately result in, is a reduction in Government spending (harder to finance deficits with Government money), and ultimately, the end in socialism. I believe the 21st century will see the reversal of the greatest mistake of the 20th.
- Between 2015 and 2025, I believe that China's economy will collapse, possibly seeing greater recessions than what the USA saw in 2008/2009. This is due to an unhealthy mix of grossly-exaggerated property prices, and rampant inflation. During this period, I imagine that there will be a great shift in power within China, and whilst it may not emerge a fully-fledged democracy... many of the other political issues in China will be resolved. With a few blips here and there, China will continue to grow to become the largest economy in the world, albeit at a much slower rate (but, ultimately, healthier) than what it's currently doing.
- Technological breakthroughs akimba. During this century (2030/2040+) space travel will finally become a fairly "normal" thing, ultimately leading to a seemingly infinite supply of just about all resources. The result will be plummeting costs everywhere. Energy, food, healthcare costs will be a mere fraction of what they are today. As a result, global poverty levels will probably drop to less than 5% of the population by the time the century's out.