We are one of the most complex and intelligent species on Earth, but we seem to be almost as foolish as any other. Like all other species, we seem driven to increase our numbers and consume available resources until we're forced by nature to stop. All species but humans live in a general balance with their ecology, not because they are wise, but simply because the local ecology limits them. Humans became knowledgeable enough to overcome local limitations, but the result is that we have become capable of destroying the global ecology. Our success at overcoming local limitations has led many to believe that we will necessarily triumph over global limitations, but unless we colonize other planets, that is impossible. To refuse to acknowledge global limits is sheer stupidity.
When I say "our civilization", "humans", and "we" I refer to all peoples in or emulating Western civilization. There do exist, scattered in remote locations, groups of humans with ancient cultures, some dating back over 12,000 years. They have survived for so long only because they've lived in harmony with their ecology. But very few of these people exist any longer. Most have been murdered by our civilization as it robbed them of their resources. Some of the very last few are under attack now, like the Hadzabe in Africa. So they are not the bulk of humanity.
The great frustration is that we are knowledgeable enough to foresee the course of our actions, to know that we should not continue acting the way we are, and yet we are so foolish as to continue anyway. Of course not everyone knows. Indeed most people are completely and even willfully ignorant. But as a whole, we know it, just as certainly as we know mathematics, chemistry, and physics. We have the technology to communicate the information to the people who most need to know it. There is no excuse for the powerful to continue leading the masses down this course, and the reason they do seems to be pure greed, like the fishing corporations that have no problem fishing the entire ocean to extinction for a quick buck today, though it means the loss of all seafood forever.
The great disappointment is that we have such potential as a species, but we're throwing away what will likely be our only chance of reaching that potential so we can transform our remaining natural resources into worthless trinkets as fast as possible, to make mega-profits for the mega-corporations.
People seem to think there is no pressing need to change. Things don't seem that bad. At least not in the wealthy nations. (The collapse is already well underway in several poorer nations.) But perhaps this analogy will be instructive. Consider a jar full of nutrients. A scientist places into the jar at 11:00 a tiny speck of bacteria. Recall how bacteria grow -- one bacterium divides to become two. This particular species of bacteria divides once per minute. The scientist observes at 12:00 that the nutrients are completely consumed and the jar is full of bacteria. What happens after 12:00? Without food, the trillions of bacteria will all die very quickly.
Now let me ask you: when is the jar half full? Most people say 11:30, but no! The jar is half full at 11:59, just one minute before it's completely full! And if you were an average bacterium in that jar, when would you first notice that there's a problem? Well, an average bacterium, like an average human, would probably not notice until it went to get some food and found that there was nothing left. But let's say you were a very forward-looking bacterium. When would you notice the danger? Most people I've asked say 11:55, but I don't think so! At 11:55, 97% of the food is left (!), so who would think that they were going to run out of food and die just 5 minutes later? Now imagine that at 11:58 they realize the danger, and these bacteria scour the globe, cut down the rain forest, blow up all the mountain tops, etc., and manage to acquire 3 more jars full of nutrients. That's tremendous — 3 times as many resources as they ever knew existed. How long do you think it will last? Incredibly, most people say "3 more hours". No, it will only last 2 more minutes. By 12:02, all four jars will have been consumed, and the bacteria will die. This is the danger of exponential growth. It sneaks up on you and suddenly explodes. It is impossible to sustain in a finite environment, like the Earth.
Do humans exhibit exponential growth? You'd better believe it. Whenever you hear something like "demand for oil is growing at 4% per year", that is exponential growth, and 4%, although it seems so small, is a dangerously high rate of growth indeed. Even our population growth, about 1.5% per year, is dangerously high. In this analogy, then, where are humans at with their resources? Well, we seem to be at around 11:58 and 30 seconds. We don't have much time left.
The only reason we've been able to grow to our current population is because of modern agriculture, and modern agriculture is essentially a process for converting fossil fuels into food. What passes for agricultural land today has largely been depleted to the point where crops could not be grown without massive fossil fuel inputs, especially fertilizer, which is made from fossil fuels. Fossil fuels are also used by the machines that work the soil and transport the produce from the farms to the supermarkets. Petroleum will last only a couple decades more, as exports from oil-producing countries seem to have peaked around 2005 and are expected to decline quickly. Natural gas is expected to begin its decline about one decade after petroleum, and coal not long after that. Even if the US gets its way in Iraq, opening up Iraqi oil and gas to rapid exploitation, it would only extend the supply a decade further, and would make the eventual decline that much more severe.
Before we started using oil, in 1858, the world population was about 1.3 billion people, and the ecology was far healthier than it is today. Due to our rampant destruction of the ecology and our depletion of the soils, the human carrying capacity of the earth is greatly reduced from its 1858 levels, and it is unlikely to be capable of sustaining even 1.3 billion people. Without oil (ie, modern agriculture), the Earth cannot sustain the 6.5 billion people living here, let alone the 8 or 9 billion people that are expected to be here when the problems really begin to start in the next few decades. Perhaps 500 million to 1 billion people will survive. This means that about 90% of humans will die, and they won't go quietly into the night. Countries like America will be hit hardest. Like Rwanda in 1994 as it bumped up against ecological limits due to overpopulation, our civilization will likely dissolve into crime and eventually mass murder. Governments will attempt to remain in control as long as possible, using all necessary means to do so. Slave work camps, brutal totalitarian rule, summary executions, and other horrors are not too improbable.
Technology isn't likely to fix this problem. There are currently no viable alternatives to fossil fuels, not even in development. Wind, solar, etc. cannot power our current infrastructure, both because they lack the energy density, portability, and/or EROI (energy return on investment) of fossil fuels, and because we don't have the resources to convert our infrastructure to another system. Better extraction technologies can potentially double the amount of available fossil fuel resources, but remember the lesson from the jar of bacteria. Doubling the number of available jars only buys the bacteria a single minute longer to survive. The chance of us inventing our way out of this is quite low.
But it gets worse. It's not only about energy. Fresh water, food stocks, topsoil, and biodiversity are all necessary to human survival, and all are in decline. Arable land and mineral and metal stocks are also declining. Pollution is increasing exponentially, and is threatening long-term human survival. Then there's global warming, which promises to make food and water even more scarce, spread disease, and destroy the predictability of the climate, which is necessary for human settlement. All of these problems are converging on us now.
Our destruction of the ecology is so severe that we have created the worst extinction event in history. Some 20,000 or so species are now going extinct every year. This is far worse than even the great K-T extinction event that marked the end of the Cretaceous period (and did in the dinosaurs, along with 30-40% of all other species alive at the time). It is expected that most species of mammal will go extinct within the next 50-100 years. It is entirely possible that this will include modern humans. We are not immune. In fact, our tremendous dependency on modern, energy-intensive technology means that we have forgotten how to live in the kind of natural environment into which we will be thrust over the next several decades.
Having divorced ourselves from nature, we humans are not important to any ecosystem, and in fact have become a destructive element, more akin to a plague or virus. The ecology does not need humans, but humans absolutely need the ecology. Despite our hubris, we cannot survive without it. Many of the species going extinct are important to their ecosystems, and their loss degrades the ecosystem further. It is my sincere hope that our civilization perish quickly, so that we don't destroy what little is left of the ecology while we flail around trying to prop up our provably unsustainable systems. If we're lucky, our descendants will have better lives than we.
Having consumed all of the easily exploitable, dense energy sources, we may never be able to rebuild our civilization. It's disappointing, but in a way I'm glad.
[UPDATE: Worldwide rice shortages are now occurring, and moderate rice rationing has begun in the United States. This is the first time ever that a food staple is being rationed across the United States. I predict that the rice troubles will get worse, and that wheat will be the next crop to fail. Taken together, rice and wheat provide most of the world's food.]
[UPDATE: As far as oil goes, while crude oil is indeed declining, it turns out that there is a lot of oil available in shale deposits. If we can find a way to extract oil from shale as rapidly as we can pump liquid oil, then it could feasibly replace conventional oil.]