Homo Sapiens changes its environment. Humans clear forests to make farms; they dam rivers to control floods; they cover land with their homes and cities; they dig up the ground to obtain mineral resources. Up until just recently, the species was too sparse and too weak to make substantial changes to their environment. But now the impact of Homo Sapiens on its environment is growing rapidly. They are changing their environment faster and faster.
It is an iron law of evolution that every species must adapt to a changing environment or go extinct. Homo Sapiens has demonstrated a remarkable ability to change its culture to adapt to new environments. Indeed, one of its greatest advantages over other species is that, while other species require perhaps 10,000 generations to genetically adjust to a big change in the environment, Homo Sapiens can adjust to a new environment in just a few generations. Nevertheless, human culture is not instantly adaptable; social mores tend to resist change, limiting the rate of change to a few generations.
Happy changes can take place rapidly: Grandpa and Grandma may reject those newfangled smartphones, but the grandkids have made smartphones an important part of their lives. The immediate existential threat of nuclear weapons has made traditional warfare obsolete, and knowledgeable people quickly adapted, but the human population as a whole is still unable to purge itself of its militaristic fantasies. The abolition of warfare remains several generations in the future, in the most optimistic assessment. In like fashion, the response to environmental pollution was fairly quick when its costs were immediate and obvious.
Unhappy changes, however, take longer. Abortion, for example, became medically reliable perhaps 80 years ago. Society has been unable to adjust to the new medical reality and so the policies controlling the use of this medical technology remain highly controversial.
The greatest failure of the species lies in its inability to cope with subtle long-term changes to the environment. The obvious example of this is the response to anthropogenic climate change. Scientists have made it quite clear that carbon emissions will cause great damage in future decades. Yet 30 years after they first became aware of the problem, Homo Sapiens still resists taking the actions necessary to fend off the impending disaster.
Part of the problem arises from the fact that the complexity of current technologies exceeds the intellectual capacity of most humans. Climate change is an immensely complex subject that few people grasp, yet a lot of people, for reasons of primitive tribalism, oppose taking action to avert or reduce its impact.
Economics is another area that has long surpassed the comprehension of most humans. Almost every economist in the world will tell you that free trade is a desirable ideal, something to be limited only in special situations and only temporarily. Yet a wave of anti-globalisation threatens to increase trade restrictions, to the detriment of all.
Another example is provided by nuclear power, which has long offered humans an excellent source of energy. Yet, the terrible power of nuclear weapons is somehow illogically transferred to nuclear power plants, and the fear of radioactivity only adds to the resistance. There is simply no rational case against developing nuclear power, yet humans remain reluctant to take advantage of this resource.
Homo Sapiens is a species best adapted to operate in small groups of hunter-gatherers. Yet the cultural and technological difference between a modern office worker and a Pleistocene hunter-gatherer is almost impossible to fathom. That office worker’s mind is no different from the Pleistocene hunter-gatherer’s. It is still dominated by tribalism, emphasis on social reasoning over logical reasoning, and emotionalism.
It all boils down to this simple graph:
When the blue line crosses the red line, the extinction of Homo Sapiens begins. With great effort, humans could conceivably push the red line upwards, but this will be opposed by humans who resist change (normally called “conservatives”). Humans really can’t do anything about the blue curve; if one country refuses to advance technology, another one will.
Thus, the extinction of Homo Sapiens is inevitable. However, there is a fine point to add to this. Once the blue line crosses the red line, the inability of Homo Sapiens to adapt to its environment will lead to various disasters that will sharply reduce its population. That, in turn will reverse the upward direction of the blue line. Unfortunately for Homo Sapiens, the same virtuous circle that enables ever-advancing technology becomes a vicious circle when it starts to reverse. Reduce the population, and there will be insufficient specialization to maintain the current technology. As the technological level of civilization declines, it will drag down population, which will reduce specialization even further, which will cause more reductions in population. This process will continue until Homo Sapiens reverts to the condition for which it is optimally adapted: a hunter-gatherer lifestyle.
The Mechanics of Collapse
How, exactly, will civilization collapse? The obvious endpoint is a nuclear war, and this is certainly a real possibility. For example, it is entirely possible that a confrontation in the South China Sea could trigger a nuclear war. China is dead set on establishing its sovereignty over the entire area. While its claims are illegal, the intensity of Chinese nationalism is so great that it is entirely feasible that they would use nuclear weapons to assert themselves. The catastrophic scenario runs as follows:
The USA decides to prevent further Chinese incursions into the South China Sea, using force if necessary. It sends a carrier group into the region to enforce a blockade against military facilities in the South China Sea. The USA rightly figures that the Chinese cannot defeat an entire carrier group — one of the most powerful military units in existence — using conventional forces. What the USA does not anticipate is that the Chinese would use a ballistic nuclear missile against the carrier group. This would annihilate the carrier group. China asserts that it used the nuclear weapon on its own territory, and therefore was not an act of nuclear war. The USA is now in an impossible position. Either it retaliates against China, expanding the war and risking a catastrophic nuclear exchange, or it backs down and accepts defeat. The American public is just stupid enough to prefer a nuclear exchange over an admission of defeat.
However, this scenario remains unlikely, as I doubt that the US would be stupid enough to militarily challenge China in the South China Sea. The only factor that makes this even plausible is the presidency of Mr. Trump.
It is more likely that a nuclear war will be the last act in a long degradation of international relationships. The steady progress of Homo Sapiens towards a peaceful planet has been halted by increasing nationalism in many countries. The sudden jump in progress in the aftermath of the collapse of the Soviet Union was caused by the global recognition that the USA was clearly the world leader and would strive for policies beneficial to humanity as a whole. However, the American invasion of Iraq shattered the image of the United States as a positive force in international relations. Confidence in American leadership was further damaged by the use of torture and the abandonment of the rule of law symbolized by Guantanamo and the abuse of prisoners at Abu Ghraib. Even more destructive was the worldwide near-depression caused by failures in American regulation of its financial regulation. The destabilization of the Middle East by the USA triggered the Arab Spring, which led mostly to more repression and civil war in Syria. The financial crisis that America started led to serious economic crises in a number of European countries, further eroding confidence not just in American leadership, but in the European Union.
The rapid collapse of American prestige triggered a rise in nationalism worldwide. If countries could not rely upon the USA to preserve the global order, they would have to fall back upon their own resources. Eventually the wave of nationalism swept into America as well, leading to the election of Mr. Trump, a disastrous development that destroyed all semblance of world leadership by the USA.
The resulting scramble of “every man for himself” among nations will wipe out the power of international institutions to dampen crises the world over, accelerating the collapse of global comity. Minor disagreements will mushroom into military confrontations. Military spending the world over will increase dramatically as nations seek to prepare themselves for the war that now seems inevitable.
Climate change adds pressure to the situation. Millions of people will be displaced by rising sea levels; the USA will of course refuse to accept any of the refugees. That will trigger bitter resentment among the countries who did take in climate change refugees. Terrorism will find a new driving force in the sufferings of climate change refugees. Americans will respond to that terrorism with even stronger nationalism and increased military spending. Their overwhelming military strength will give them a false sense of invulnerability. Owners of American debt the world over will begin dumping their American assets, causing American interest rates to rapidly climb and driving the economy into a deep depression. All of this will only prod the Americans in even greater fury and the use of its vast military resources to take what they consider theirs by right. China might well organize economic sanctions against the USA, at which point everything will spiral out of control.
That is only one scenario that would lead Homo Sapiens to destroy its civilization. However, nuclear war is not necessary to destroy civilization; that could just as easily be triggered by nonviolent developments, climate change being the most obvious. Climate change has a long lag time between causes and their effects, roughly 30 years. The climate changes that take place today are the consequence of carbon emissions up to the late 1980s. The full effect of current carbon emissions will not be felt for another 30 years. Any politically feasible suite of policies to reduce carbon emissions will come far too late to deflect economically catastrophic consequences of climate change. Already climate change is wreaking something on the order of hundreds of billions of dollars of damages each year, and those costs will be rising dramatically in future decades.
The global economic output just now amounts to about $75 trillion. During the latter half of the 20th century the global economy grew by perhaps 3% per year. At that rate of growth, the world economy should grow by about $2.5 trillion per year. But the rising costs of climate change will eat into that number. When those costs reach $3 trillion per year, they will cancel all economic growth; humanity will no longer be growing wealthier each year.
One of the most fundamental rules of politics is that economic privation drives political unrest. Homo Sapiens expects economic growth over the long run. When humans realize that their situation is worsening, they resort to desperate measures — which always make matters worse. Even without war, economies around the world will collapse under the increasing strains of climate change. Economic collapse will kill not with bullets but by the collapse of the complex logistical systems necessary to keep billions of people alive. Civilization will regress until tiny self-sufficient groups stabilize the situation. At first they’ll take advantage of remaining technology, but as the technology wears out, their output will fall, further reducing the population. Once all the technology has worn out, the only way people will survive is through the means that cannot wear out: human bodies. The population will stabilize at Pleistocene levels with a few million hunter-gatherers populating the planet.
Thus will end the meteoric career of Homo Sapiens.