1. Environment. When a Chinese river starts burning because it is all essentially sewage that's a problem. When crops don't grow because of a severe drought or severe flood, that's a problem. When the temperature of the air and sea continues to rise at an accelerated rate, that's a problem. I could list environmental problems ad nauseam. So what is the solution? We don't have one. When mass destruction across the entire planet starts to occur due to the weather, it will be too late to try a quick fix. It took us all of human existence to get to the point where we polluted the entire planet to the point of no return. The environment is a lost cause. Any actions taken now will be too late, despite the magnitude of the actions to repair the earth's environment for future livable conditions. Sorry for the bad news, but it's coming and anyone with an objective analysis concerning only the planet's health would be hard pressed to show evidence to the contrary.
2. Nuclear Instability. I actually think that this is one of the least concerning reasons our society may perish. The super powers around the world (U.S,, U.K., India, China, & Russia) understand the meaning of mutually assured destruction when it comes to the idea of unleashing an arsenal of nuclear missiles. The more likely scenario is not that we trade nukes in the air with China, but that a rogue state or terrorist organization finds a way to deliver a nuclear payload that starts an international crisis, paving the way for an all out nuclear holocaust. This still seems relatively unlikely at this time.
3. Overpopulation/Limited Resources. The population of earth continues to grow and is expected to surpass 10 billion people by 2100. That may sound a long time away, but that's really only 86 years, or a lifetime for many. Clean water, electricity, oil, food, and all the other resources needed to sustain this type of global population growth is unimaginable. That's not to say we are incapable of handling it, but what happens if key resources begin to dwindle? Who is gets to be first in line to get what's left? The wealthy of course because they can afford to pay out the nose for basic services a farm hand in Nicaragua cannot. Thus leads to protests, riots, and all the other fun stuff when a society turns on its head for basic survival. It has been estimated that within 30 days without electricity all of society breaks down causing mass anarchy. Will the chaos created by a lack of essential resources plunge all of humanity into a downward spiral, or will it only affect the least capable of surviving? This is yet to be seen, but if a run on grocery stores instead of banks starts happening in America, you can forget about lunch at Sardi's everyday.
4. Politics. The biggest polluter in the world, China, has no plans to stop pumping all sorts of wonderful chemicals and poisons into our air and water. Other countries take the sustainability approach (e.g. Costa Rica). But despite what 99% of the nation states in this world do, it only takes one to wreak havoc for the rest of us. Essentially this means that the future of our society is made good only if there is essentially total compliance with environmental policies (not yet created) to prevent the environment from imploding faster than it already is. If one major player decides it doesn't want to be "clean" who is going to stop them? Nobody. Not to mention that the speed of politics in this country has never been slower with our current Congress being the least productive in all American history. So even if the policies to help out our planet start to rumble in the corners of the Capital building, it could be decades before any meaningful action is taken if ever.
5. Faceless Greed. The only person these days that seems concerned with helping the poor is the Pope. And he has been strongly criticized by the American plutocrats. As long as there is money to be made today at tomorrow's expense, no changes to our current capitalist run society will occur. Our society is essentially like Social Security, we borrow today and worry tomorrow about paying back what we borrowed. Unlike Social Security, we are borrowing from the planet and have no intention to pay it back, leaving the planet bankrupt. Can you kick a dead horse? Yes, but it won't make the corpse jump up and start tilling ground again. The endless greed for more, is probably the most dangerous problems facing our society. We've all read about the revolutions of the past which were precipitated by the rich starving the poor to death (e.g. The French Revolution). As we have seen recently in Egypt and other parts of the middle-east, a revolution doesn't make things perfect as soon as a leader is deposed. Many times, the people become even worse due to the new management that may be even more inept and greedy than the management that was just kicked out the door.
So there you have it, B's recipe for the end of civilization as we know it. We have a couple or more generations to go before the dominoes start to fall. But they are at the tipping point. So if you're young, congratulations, you may be the last generation on earth not to experience the collapse of human society, if you're old, you really don't have to worry about anything. So drink, eat, play, and know that all the problems of the world will fall to our descendants who will generously pick up the unpayable tab for us, whether they want to or not.