Sustainable Development in Asia: The Long View

Lecture at Fudan University, Shanghai, China on November 7, 2026 (Transcript)

Thank you very much. It is wonderful to be back at Fudan, and wonderful for me to meet Pepe Escobar face to face for the first time. I understand that he has just spoken to you. He is a great journalist, and I admire him. We can talk about many things, because this is a very interesting time in the world, a time of major transformation and transition. I am going to take one phrase from the title, "the long term," to give some historical perspective on where we are right now. If you will permit me, I will start 3,000 years ago, work my way up to the present, and then look toward the future.

I want to take the long view because we are at a historical juncture at which Asia has resumed the central role in the world economy. This is the result of changes over the past 75 years, and especially of changes in China over the past 45 years. As best we can measure, using the proper comparison of output at purchasing power parity, Asia now produces about half of world GDP, and it is home to about 60 percent of the world's population. Asia has been at the center of the world's population and economy for most of the last 2,000 years, and arguably for most of the last 3,000 years, if we had the data to show it. I want to explain why that is, what pushed Asia out of the center of the world economy starting around 200 years ago, and what has led to Asia's return to center stage. I also want to say what this means geopolitically and where we stand today, because these very days are quite significant in historical perspective.

Why has Asia been at the center of the world economy for most of the last 2,000 years for which we have some data, and arguably for longer? The answer is a little surprising. The answer is nitrogen. I could also give another answer: cyanobacteria. Asia has been the center of world population for thousands of years mainly because agriculture in Asia could support larger populations at higher densities than anywhere else in the world. There is a fundamental biogeographical reason for Asia's central place. When I say Asia, I mean especially East Asia, which historically means mainly China, and South Asia, which means mainly the Indian subcontinent. East Asia and South Asia together have been home to nearly half of the world's population for at least 2,000 years. That is quite surprising, since they account for far less than half of the world's inhabited land. The explanation is the extremely high population density of China and India, then as now. And why is population density so high? Again, the answer is nitrogen and cyanobacteria.

To understand the long-run distribution of population, one has to understand the basic activity of humanity for essentially all of our existence as a species, which is getting enough food to survive, roughly 2,000 to 2,200 calories per person per day. Before about 10,000 BC, and I promise not to spend too long on this, all human activity was hunting and gathering. People lived by moving around as nomads, and they hunted, fished, and foraged for their subsistence. Starting around 12,000 years ago, in several parts of the world, the discovery of crop production made permanent settlement possible. For the first time, human populations became settled, and we date the beginnings of civilization to these permanent settlements. Permanent settlement depends on the ability to grow enough food, year after year, to stay alive.

For most of the past 10,000 years, the margin of survival was very small everywhere in the world. Food production was just a little above human need, and in bad periods of drought or crop failure there were famines and reversals. What determines how much food can be produced in a given place? Crops need nutrients, water, and a long enough growing season. In some places the growing season is too short for even a short-season crop. In very dry places, short rains may produce enough grass to feed animals, which supports pastoralists who raise sheep, goats, and other grazing animals, but the population densities that such livelihoods support are extremely low. The polar regions, in the far north and the far south, have almost no human population. In places with enough rainfall and a long enough season, especially in the temperate and subtropical climates, crops can be grown each year. How large a population those crops can support then turns out to be limited mainly by the nutrients that the crops take up from the soil through their roots.

Plants need many nutrients, including nitrogen, phosphorus, potassium, and various micronutrients, but the limiting factor in most places and at most times in history has been nitrogen. Nitrogen is a basic element of protein, which is fundamental to the structure of plants and to our food, because we need nitrogen to make our own amino acids and proteins. Why is nitrogen scarce? Nitrogen is the main element of the atmosphere, but it is in a form that is not biologically available. It is dinitrogen, N2, by far the most plentiful molecule in the atmosphere. Neither people nor plants can use N2 directly. Plants can take up nitrogen only in reactive forms, mainly as ammonium or nitrate, and turning N2 into these forms depends on physical and biological processes. Lightning fixes a certain amount of atmospheric nitrogen each year, and certain bacteria convert dinitrogen biologically into forms that plants can absorb. The availability of nitrogen in the soil is therefore limited by these physical and biological processes, and one can track how much nitrogen they make available.

The problem is that when a crop grows, it absorbs nitrogen from the soil. People take the harvest to their village and eat it. We do not retain most of the nitrogen we eat; we excrete it. That nitrogen is recycled in nature, but it generally volatilizes into the air, disperses, or leaches into the groundwater rather than returning to the field. The harvest therefore removes nitrogen from the soil and leaves less for the next year's crop. The removal of nitrogen from the soil is the limiting factor in how much food can be grown consistently, year after year.

In most places in the world over the past 10,000 years, agriculture took the form of what is called shifting, slash-and-burn, or swidden agriculture. A household grows food on a plot of land for a year or two until the nitrogen is depleted, and then moves to another plot, perhaps tens or hundreds of meters away. It can return to the original plot after perhaps 15 or 20 years, because by then lightning and bacteria have restored enough nitrogen for another year or two of crops. A household might therefore need 20 hectares of land to support itself, moving from plot to plot within an area that allows each plot 15 or 20 years to recover its nitrogen. This kind of agriculture characterized most of humanity, in most places, for most of human history. It is a system designed to keep enough nitrogen in the soil to grow enough food to keep people alive. But the population density it supports is very low, because each plot is cultivated only a year or two out of every 15 or 20 years, and the rest of the time the land must lie fallow, regrow vegetation, and above all rebuild enough nitrogen for another crop.

There are, however, solutions that support more intensive agriculture, and that is where most of the world's population has lived. In some places, rivers flood the farmland each year according to the cycle of the rains, and the floods bring nutrients, including nitrogen, from upstream. That is why the Nile valley and delta were among the most densely settled places in the world. The Kingdom of Egypt, already about 5,000 years ago, had a very dense population that could grow crops every year at high intensity, so much so that Egypt produced a surplus for export. For centuries, grain from the Nile was a mainstay of the food supply of Rome, a city of perhaps one million people. That was possible because of the flooding of the Nile. Asia has its own great river systems. We are in one of them right now, the Yangtze basin. The Yangtze, the Yellow River, the Indus, and the Ganges are all alluvial systems in which the sediment carried by the annual rains, in Asia's case the monsoon, brings nitrogen. This is one part of the story: high population densities were possible along river systems where annual floods replenish nutrients from upstream.

There is a second way that is extremely important, and that is cyanobacteria, or blue-green algae. Cyanobacteria are among the organisms that fix nitrogen, and they live in flooded rice paddies, which are the main form of agriculture in East Asia and South Asia. There is therefore a tremendous amount of nitrogen fixation in flooded rice, and places with flooded rice are places with high population densities. That is the most fundamental reason for Asia's central role in the human population.

There is a third way to concentrate nitrogen, and that is the mixed farming system, in which farms both grow crops and raise animals. That was the European solution. It does not support as high a density as rice paddies or alluvial systems, but it concentrates nitrogen in a different way. On an ancient or medieval European farm, there was a plot of land for crops and a large pasture beyond it. The pasture grew no crops; it fed animals, especially cattle, sheep, and goats. The grazing animals took in nitrogen as they fed and were then brought back into a fold next to the cropland, where their manure became the fertilizer for the fields. As in swidden agriculture, land beyond the cropland plays a role, but instead of rotating crops across that land, the farmer keeps permanent cropland and uses the outer land for animals that bring nitrogen back to the crops. The European mixed farm worked especially well in places with cold winters, because the transfer of manure does not work well at high tropical temperatures. In the tropics, the animals are not gathered into winter folds where manure piles build up, and the nitrogen in manure volatilizes into the atmosphere or leaches into the groundwater too quickly for the crops to absorb it.

We therefore have a variety of food systems around the world. Some support only very low population densities. The lowest is pastoralism in very dry places, where short bursts of rain grow grass. The pastoral livelihood is to follow the rains through the year, moving in a cycle as nomads or semi-nomads rather than as a settled population. Next comes swidden agriculture, in which cultivation rotates across the land at low population density. Then there are three systems that support rather high population densities: farming along river systems, paddy rice, and mixed farming. There is one more system, used in Asia on a scale seen nowhere else, and that is returning human waste to the soil. People eat the food and excrete the nitrogen, and when human waste is put back on the soil, most of the nitrogen that was in the food returns to the fields. In English we call it "night soil." It was a very intensive activity in and around the major cities of China, Japan, and a few other places, on a scale never matched in Europe or elsewhere. The point is that as far back as we can see, using archaeological, historical, and census data, Asia, especially East and South Asia, along with a few other places such as the Nile valley, had concentrated populations, while most of the rest of the world had very sparse populations.

The Americas and Africa each faced a particular burden. In the Americas, there were almost no domesticated animals other than dogs and the llamas and alpacas of the Andes. Most of the large land mammals of the Americas went extinct around 12,000 years ago, in large part through hunting by the first Americans. Most disastrously, the horse, which had been widespread in North America, disappeared. It is a bad idea to drive the horse to extinction, because then you have to walk for the next 12,000 years. There was no animal to ride, and outside the narrow stretch of the Andes, where llamas carried loads, there was no animal transport. Long-distance transport and communication were possible only on foot, by canoe along the rivers, or in limited ways along the coasts. The Americas therefore largely missed out on intensive agriculture. Almost all of the Americas practiced some form of rotation, with exceptions such as the Valley of Mexico, the site of today's Mexico City, where intensive cultivation on the chinampas, fields built up in the shallow lakes, supported the most densely populated part of the Americas.

Africa had another serious problem. The burden of tropical disease was so high that in many places it was impossible to keep farm animals alive, because of trypanosomiasis, carried by the tsetse fly, and other animal diseases. There were very few places of high population density in all of Africa: a few in the Niger River basin and, above all, the Nile valley in North Africa.

As best one can judge, this map of the world has been remarkably consistent for at least 2,000 years. This is why Asia was at the center of world population, and why it was also at the center of the world economy and of world politics, because high population density made it possible to sustain large cities, a division of labor, and large political entities. Asia built the largest political entities in world history. China is unique as a state that has been large and unified for most of the past 2,250 years.

China was highly populous because of its two great east-west river basins, the Yangtze and the Yellow River. That high population density enabled it to build a large state, first unified in 221 BC, which has remained mainly unified for about 70 percent of the time from 221 BC until today. China is unique in history as a large polity without a lasting rival over such a long period. There are only three places that had long-standing large political entities with large populations. China was one of them, and it was mostly unified. India was the second, for similar reasons, but India's history was more fragmented than China's; it was unified for perhaps half the time. One reason is that the Indian subcontinent is far more diverse geographically than China. Between the north of India, with its great river systems, and the Deccan Plateau there is a major ecological divide, and political integration was therefore much harder on the subcontinent. Integration occurred briefly under several earlier empires, partly under the Delhi Sultanate, to a considerable extent under the Mughals, under British India, and now under modern India. For much of the time, however, India was divided into dozens or even hundreds of principalities and smaller states.

The third area where large polities were built was Europe, on the basis of its mixed farming system and of the very interesting arrangement by which Egypt fed southern Europe, above all Rome until around 330 AD, and then Constantinople for another 300 years after it became the capital of the Eastern Roman Empire. In political terms, the difference between China and Europe was that while Europe supported states and major cities just as China did, Europe fragmented at the end of the 5th century and never reunified, whereas China remained mostly unified for 2,000 years. Around 100 AD, China and the Roman Empire were quite comparable. Each had a population of perhaps 50 to 60 million people and an area of roughly 5 to 6 million square kilometers, so there appeared to be a rough balance between the Roman Empire and the Han dynasty. The difference is that the Roman Empire in the west fragmented and came to an end in 476 AD, and it never reunified. There has been no period of European unity since then. Today's European Union is one of the few experiments in European unification, and its members do not like each other very much; they have different languages, different outlooks, and competing politics. So far the European Union has held together, but it is a much more fragmented system than China, whose unity has carried through the Qin and Han, the Sui, Tang, Song, Yuan, Ming, and Qing, the Republic, and the People's Republic. This is an almost continuous span of political unity and integration, built on an enormous population and very large cities, and supported by your wonderful blue-green algae and your great river systems.

That is the long history. What does it mean for today? As far back as we can understand long-term history, China was the unique large, integrated country. It held roughly a quarter of the world's population, at times more, and because output per person did not vary greatly across settled societies, a similar share of world output. Urbanization rates were 5 to 10 percent wherever there were densely settled populations, and near zero among swidden or pastoral populations. China was the center. Together, China and India held around half of the world's population, and sometimes more, with the sophisticated division of labor that went with highly integrated economies and societies. This integration rested on sea-based as well as land-based trade, and in China on the brilliance of the Sui dynasty in linking the two great river basins with the Grand Canal, built in the first decade of the 7th century and expanded under the Tang. It is one of the great achievements of economic integration in world history. By the way, I know that Chinese audiences check every fact, and that I will then receive a thousand emails correcting me. So let me say at the outset that I am speaking without notes, from memory, and I may have some dates wrong by a few years. Please accept my apologies in advance.

What deranged this normal situation was the rise of the European empires from the 16th century to the 20th century, which by the 19th century had overturned the normal course of history. Europe is the western peninsula of Eurasia. It is a very interesting place, but it did not dominate world affairs for most of the last 10,000 years. Until around 1600 or 1700, I would say, no one paid much attention to it. It was the far western end of the Eurasian landmass, while the large populations and the main action were in East and South Asia, so that what happened at the western end of Eurasia was something of a curiosity. There was east-west trade going back 2,000 years, but Europe did not bother Asia very much. Asia, from time to time, bothered Europe: when the Huns arrived in Europe in the late 4th century and pressed deep into the Roman world in the 5th, or when the Mongols reached the Hungarian plain in 1241 and then withdrew in 1242 after the death of the Great Khan Ögedei. Most of the time there was some long-distance overland trade along the Silk Roads, and Europe did not bother Asia very much at all.

That changed in modern history. The beginning of the change was Vasco da Gama's voyage of 1497 and 1498, which rounded the Cape of Good Hope at the southern tip of Africa and reached India in 1498. The Europeans learned that they could sail down the west coast of Africa, round the continent, and use the monsoon winds to sail to India and beyond. That began European colonization in the Indian Ocean region. Six years before Vasco da Gama reached India, in 1492, Christopher Columbus sailed west, thinking that he would reach Japan and China. Instead he reached a landmass that neither he nor other Europeans knew about, the Americas, and that began Europe's conquest and colonization of the Americas.

Both events transformed world history. Suddenly two vast continents, North and South America, were open to Europe. They were open in part because the native population fell by around 90 percent between 1500 and 1600, by most estimates, mainly because of pathogens brought from the Old World to the New World. The peoples of the Americas had arrived 15,000 or more years earlier and had never been exposed to these diseases in their biological history, and they succumbed to Old World diseases such as smallpox, measles, and typhus brought by the Europeans. There was enslavement and conquest as well. A Native American population of perhaps 50 to 60 million people, by most recent estimates, very nearly disappeared. The Europeans took possession of two continents, which provided vast resources for Europe and a foothold for its early development, sometimes called primitive accumulation. It was a big boost to Europe in many ways.

Europe's big breakthroughs came with technological advances, most importantly steam-based industrialization, which came first to England. For that reason, Britain became the main hegemonic power of the 19th century. The economic data show that as late as 1820, Asia still produced about 60 percent of world output. Until the early 19th century, the balance between Europe and Asia had not changed very much. The 19th century brought the decisive change of modern history.

First, Britain colonized India and devastated it. India went from being one of the world's two great manufacturing powers, a rival to China in manufactures and especially in textiles, to virtual economic collapse, with repeated famines and mass starvation in the late 19th century. These famines were triggered in part by physical phenomena such as El Niño cycles, but it was the British reorganization of India as an imperial holding that turned these events into catastrophes in which many millions of people died. India collapsed as an economy under British rule. China had a similar experience. It never succumbed to direct imperial rule as India did, but from 1839 to 1949, the so-called century of humiliation, it suffered one devastation after another. First came the European assaults: the First Opium War of 1839 to 1842 and the Second Opium War of 1856 to 1860. The Taiping Rebellion, from 1850 to 1864, was perhaps the largest uprising in China's history, and indeed in world history, with tens of millions of people perishing. Then came Japan's wars against China, which began in 1894 and continued, on and off, for half a century until 1945. China too collapsed economically between 1839 and the founding of the People's Republic of China in 1949.

As best we can judge from the data, Asia's share of world output fell from about 60 percent in 1820 to about 20 percent in 1950. The year 1950 was rock bottom: Asia had about 20 percent of world output and more than half of the world's population. By 1950, even after two European civil wars, the First and Second World Wars, Europe and the United States together produced about 55 to 60 percent of world output. By the middle of the 20th century, the long history had been reversed. Asia's age-old central role in the world economy had been destroyed by a century and a half of European domination. The so-called Western world, meaning Europe and the United States, now held the predominant share of world output, even though it had less than a quarter of the world's population.

Western countries viewed this as normal and had good explanations for why it was the normal state of affairs, but it was anything but normal. It was a reversal of 2,000 years of history, based on 200 years of European imperialism. At the end of 1945, when the second European civil war, World War II, ended, Europe was financially, economically, morally, and physically exhausted, and one way or another its empires came to an end all over the world. In some cases Europe gave them up. In other cases it fought to retain imperial control and ceded its empires only decades later. In still other cases the United States took up the cause of defending Western imperial control, as it did in Vietnam, where Western control finally ended only in 1975. The point is that by the end of World War II the European imperial system was finished. What arose in the West in its place was an American empire. America built its empire on a different principle: not direct ownership of other countries, but control over who governed them. If the United States did not like a government, it would replace it, and it did so on dozens of occasions around the world after 1945. It used a worldwide network of military bases in about 80 countries to maintain its informal, indirect empire. This was taken as the new normal: the West dominates and is the preeminent part of the world, and the United States is the preeminent part of the West, because Europe lost its empires and America took them on in this indirect form.

This view of the world had one important qualification: another European power, Russia, in the form of the Soviet Union, competed with the United States for global influence, and in ideology and economic system. That was the Cold War, from 1945 to 1991. There is a lot to say about that period, but I will say only that it was another division within the European system and another chapter of Europe's long fragmentation. In 1991 the Soviet Union itself fell apart, and Russia remained as the largest successor state. Russia is by far the largest country in the world by land area, roughly 17 million square kilometers, almost twice the size of China or the United States, though with a much smaller population. As of 1991, the view in the United States was that the West dominates the world, the United States dominates the West, and there is no longer even a rivalry with the Soviet Union, because it is gone. The conclusion was that the United States dominates the world. There is one superpower, the United States; everyone else is subordinate, and China will make our phones, thank you very much. That was basically the idea: Russia, China, India, and others would be part of an American-led order.

As I am emphasizing, this view was deeply ahistorical, and ahistorical narratives have very short lives. This one is now over. The present moment is one of widespread recognition of two things. First, Asia, not the West, is once again the center of the world economy. Second, there is no single leader of the world; we are in a multipolar world. Since independence, and especially since the start of their economic reforms some decades later, China and India have substantially closed the gaps that opened during the period of Western imperialism, not entirely, but substantially. In overall terms, measured at purchasing power parity, China's economy is now around 30 percent larger than the American economy, and China's industrial production is far larger than America's. This is clear in sector after sector: China produces more, produces very efficiently, and competes with or outcompetes the United States.

So the idea of Western dominance is clearly gone, and this is all to the good, in the sense that the imbalance that arose in the 19th and 20th centuries was not honestly earned. Innovation played a role, and that was an honest part of it, but most of the gap was opened through brutality, violence, and imperial domination. When that ended, the gap started to close, and rather rapidly, far more rapidly than the economically ignorant strategists in the United States could ever have imagined. They thought their dominance would last forever. They did not understand what was happening in China, they do not understand what is happening in India, and their view of economics is very static, so they do not understand the underlying dynamics.

Where are we today? We are in a world that has substantially rebalanced economically. Nitrogen still plays its role, with one important footnote to history. About 60 percent of the world's population still lives in Asia, but there is one difference about nitrogen today that was not true at any time in human history until 1913: we can now make reactive nitrogen industrially. This is a fundamental change in human history. Nitrogen fertilizer is produced industrially through the Haber-Bosch process, developed between 1909 and 1913, and it can be put on a ship and sent anywhere in the world. It breaks nitrogen's hold on population. The biggest effect is in Africa. In tropical Africa, the nitrogen limit was the binding constraint that kept population low. The disease burden was a contributing factor, but the nitrogen limit meant that Africa's population throughout history was between 5 and 10 percent of the world's population. With industrial nitrogen, the population of that vast continent is now soaring. In 1950, Africa had about 9 percent of the world's population; today it has about 18 percent. Africa's population rose from around 230 million in 1950 to about 1.5 billion today. By 2050, according to the UN population projections, Africa will have about 2.5 billion people, and by 2100 it may hold more than a third of the world's population, because with the availability of industrial fertilizer the age-old constraints with which I began no longer bind.

Food can now be grown wherever there is a suitable climate and growing season. If there is water, farmers can add the nutrients and use crop varieties that make it possible to support much larger populations. Food is also shipped around the world at much lower cost, so that food-producing giants such as Brazil, North America, and Australia can feed significant populations elsewhere that trade other goods and services for imported food. Breaking the nitrogen barrier through industrial processes has also fundamentally changed the demographic future.

Let me conclude so that we can have some discussion. Asia has returned to the center of the world economy. The Western economy, the United States and Europe together, is now a little over 30 percent of world output, compared with 55 to 60 percent in 1950. The West is smaller than Asia in economic size, and it does not predominate. Its share will continue to decline. Asia's share, around 50 percent today, may rise somewhat, to a peak of perhaps 55 percent, but it will not grow beyond that. Africa's share of world population and output will rise meaningfully over the next 75 years, so we will see a further reshaping of the world system. We are, therefore, in a multipolar world, a world in which the West is far from predominant. Technology has diffused, output has diffused, and economic differences have narrowed. These tendencies run very deep.

The last thing I will say is that it has taken Washington a long time to understand any of this. They are the last to know. It is hard to break delusions, and the delusion of power is very strong. The delusion of absolute power that came in 1991 with the end of the Soviet Union was intoxicating in the United States. It was "the end of history," which meant us: we would predominate for centuries to come. That vision lasted 10 or 15 years. In reality, China overtook the United States in economic size, measured at purchasing power parity, in the mid-2010s, and it matched the United States in technology in most areas around 2020 to 2025. We now have a truly multipolar world. The big challenge today is how we will live in that world. The only answer is cooperatively, because if the global powers clash in a world of nuclear weapons, artificial intelligence, and advanced biotechnology, we will end up destroying humanity itself.

When you have the likes of Donald Trump, you are never in a safe place. He is surely the worst president we have ever had, and that is a stiff competition, by the way, because we have had a large number of absolutely awful presidents. Our system produces a lot of mediocrity, but Trump is not mediocre; he is something special. The American people soundly rejected Trump on Tuesday in the midterm elections. This is a very good development for everybody. Just today he appointed the worst member of his team as his chief of staff, a person of disreputable and dangerous ideas, so we are not done. There is still some drama remaining.

There is a growing recognition in the United States that wars to secure American hegemony are useless and futile. The war with Iran was a war of American hegemony, meant to say that we and our buddy Israel control the Middle East, and it failed miserably. The American people have just shouted: "Would you stop this recklessness and attend to our cost of living, housing, health care, and education, please? That is what we care about, not whether we control the regime in Iran." This is potentially a very good development. Let me end by saying that later this month, at the APEC summit in Shenzhen, a much weakened President Trump is expected to meet President Xi, and possibly President Putin as well. It is good that they are meeting, not to divide up the world, but perhaps to say: let us stop the conflicts among ourselves; end the war in Ukraine, a war that the United States provoked by trying to surround Russia with its military alliance; stop the conflicts with China; and end the war in Iran. It is just possible that Mr. Trump will get some very good advice. Thank you very much.