Numbers Don't Lie: 71 Stories to Help Us Understand the Modern World

by Vaclav Smil

desire for fewer children has been driven by an often highly synergistic combination of gradually rising standards of living, the mechanization of agricultural work, the displacement of animals and people by machines, mass-scale industrialization and urbanization, increasing numbers of females in the urban labor force, advancing universal education, better healthcare, a higher survival rate of newborns, and government-guaranteed pensions.

And what does the future hold for countries whose fertility has fallen below the replacement level? If the national rates remain close to the replacement (no lower than 1.7; France and Sweden were at 1.8 in 2019), then there is a good chance of possible future rebounds. Once they slip below 1.5, such reversals appear increasingly unlikely: in 2019, there were record lows of 1.3 in Spain, Italy, and Romania, and 1.4 in Japan, Ukraine, Greece, and Croatia.

For every dollar invested in vaccination, $16 is expected to be saved in healthcare costs and the lost wages and lost productivity caused by illness and death. And when the analysis went beyond the restricted cost-of-illness approach and looked at broader economic benefits, it found the net benefit-cost ratio was more than twice as high—reaching 44 times, with an uncertainty range of 27 to 67. The highest rewards were for averting measles: a 58-fold return.

In 1850, the combined life expectancies of men and women stood at around 40 years in the United States, Canada, Japan, and much of Europe. Since then, the values have followed an impressive and almost perfectly linear increase that saw them nearly double. Women live longer in all societies, with the current maximum at just above 87 years in Japan.

Before the development of long-range projectile weaponry some tens of thousands of years ago in Africa, our ancestors had only two ways to secure meat: by scavenging the leftovers of mightier beasts or by running down their own prey. Humans were able to occupy the second of those ecological niches thanks, in part, to two great advantages of bipedalism. The first advantage is in how we breathe. A quadruped can take only a single breath per locomotive cycle, because its chest must absorb the impact on the front limbs. We, however, can choose other ratios, and that lets us use energy more flexibly. The second (and greater) advantage is in our extraordinary ability to regulate our body temperature, which allows us to do what lions cannot: run long and hard in the noonday sun.

In 1800, less than 2 percent of the world’s population lived in cities; by 1900 the share was still only about 5 percent. By 1950 it had reached 30 percent, and 2007 became the first year when more than half of humanity lived in cities.

The EU has just over 450 million people, less than 6 percent of the global population, but it generates nearly 20 percent of the world’s economic output, as against almost 25 percent for the United States. It accounts for nearly 15 percent of global exports of goods—a third more than the United States—including cars, airliners, pharmaceuticals, and luxury goods. Moreover, half of its 27 members are among the top 30 countries in terms of quality of life, as measured by the United Nations’ Human Development Index.

In 2018, manufacturing accounted for 9 percent of the British GDP, compared to 10 percent in Canada, 11 percent in the US, and, respectively, 19, 21, and 27 percent in such remaining manufacturing superpowers as Japan, Germany, and South Korea . . .

Japan is not only the world’s fastest-aging major economy (already every fourth person is older than 65, and by 2050 that share will be nearly 40 percent), its population is also declining.

Both countries selectively abort many girls, creating abnormal sex ratios at birth. The normal ratio is 1.06 males per one female, but India stands at 1.12 and China at 1.15.

Manufacturing has become both bigger and smaller. Between 2000 and 2017, the worldwide value of manufactured products has more than doubled, from $6.1 trillion to $13.2 trillion. Meanwhile, the relative importance of manufacturing is dropping fast, retracing the earlier retreat of agriculture (now just 4 percent of the world’s economic product). Based on the United Nations’ uniform national statistics, the manufacturing sector’s contribution to global economic product declined from 25 percent in 1970 to less than 16 percent by 2017.

The top four economies remain the top four manufacturing powers, and accounted for about 60 percent of the world’s manufacturing output in 2018. China was at the top of the list with about 30 percent, followed by the United States (about 17 percent), Japan, and Germany. But these countries differ markedly in the relative importance of manufacturing to each of their economies. The sector contributed more than 29 percent of China’s GDP in 2018—in the same year, manufacturing’s share came to about 21 percent in Japan and Germany, and only 12 percent in the United States. If you rank countries by per capita manufacturing value, then Germany, with about $10,200 in 2018, came out on top among the big four, followed by Japan with about $7,900, the United States with about $6,800, and China with only $2,900. But the global leader is now Ireland, the country that until it joined the EU (then known as the EEC) in 1973 had only a small manufacturing sector. Its low corporate tax (12.5 percent) has attracted scores of multinationals, who now produce 90 percent of the country’s manufactured exports, and the country’s manufacturing value per capita has surpassed $25,000 a year, ahead of Switzerland’s $15,000. When you think about Swiss manufacturing, you think about such famous domestic firms as Novartis and Roche (pharmaceuticals) or the Swatch Group (watches, including Longines, Omega, Tissot, and other famous brands). When you think of Irish manufacturing, you think about Apple, John...

When in 2011 Samuel Arbesman, at that time at the Institute for Quantitative Social Science at Harvard University, analyzed the lifespans of 41 ancient empires that existed between 3000 bce and 600 ce, he found that their mean duration was 220 years, but that the distribution of imperial lifespans was highly skewed, with those empires enduring at least 200 years being roughly six times as common as those surviving for eight centuries.

Energy, material, and transportation fundamentals that enable the functioning of modern civilization and that circumscribe its scope of action are improving steadily but slowly. Gains in performance mostly range from 1.5 to 3 percent a year, as do the declines in cost. And so, outside the microchip-dominated world, innovation simply does not obey Moore’s Law, proceeding at rates that are lower by an order of magnitude.

Shakespeare’s plays and poems in their entirety amount to 5 megabytes, the equivalent of just a single high-resolution photograph, or of 30 seconds of high-fidelity sound, or of 8 seconds of streamed high-definition video.

By the year 2000, all books in the Library of Congress held more than 1013 bytes (more than 10 terabytes), but that was less than 1 percent of the total collection (1015 bytes, or about 3 petabytes) once all photographs, maps, movies, and audio recordings were added.

These quantities lead to some obvious questions. Only a fraction of the data flood can be stored, but which part should that be? Challenges of storage are obvious even if less than 1 percent of this flow gets preserved. And for whatever we decide to store, the next question is for how long the data should be preserved. No storage need last forever, but what is the optimal span?

In late 2019, the world had 449 operating reactors (and 53 under construction), many with capacity factors of better than 90 percent.

In 2018, nuclear power provided the highest share of electricity in France (about 72 percent), 50 percent in Hungary, Swiss reactors contributed 38 percent, and in South Korea it was 24 percent, while the share in the US was just below 20 percent.

The only leading economies with major expansion plans are in Asia, led by China and India, but even they can’t do much to reverse the decline in the share of nuclear power in worldwide electricity generation. That share peaked at nearly 18 percent in 1996, fell to 10 percent in 2018, and is expected to bump up to just 12 percent by 2040, according to the International Energy Agency.

Larger turbines must face the inescapable effects of scaling. Turbine power increases with the square of the radius swept by its blades: a turbine with blades twice as long would, theoretically, be four times as powerful. But the expansion of the surface swept by the rotor puts a greater strain on the entire assembly, and because blade mass should (at first glance) increase as a cube of blade length, larger designs should be extraordinarily heavy. In reality, designs using lightweight synthetic materials and balsa can keep the actual exponent to as little as 2.3.

In 1800, only the UK and a few localities in Europe and North China burned coal to generate heat—98 percent of the world’s primary energy came from biomass fuels, mostly from wood and charcoal; in deforested regions energy also came from straw and from dried animal dung. By 1900, as coal mining expanded and oil and gas production began in North America and Russia, biomass supplied half of the world’s primary energy; by 1950 it was still nearly 30 percent, and at the beginning of the 21st century it had declined to 12 percent, though in many sub-Saharan countries it remains above 80 percent. Clearly, it has taken a while to accomplish the transition from new carbon (in plant tissues) to old (fossil) carbon in coal, crude oil, and natural gas. We are now in the earliest stages of a much more challenging transition: the decarbonization of the global energy supply which is needed in order to avoid the worst consequences of global warming. Contrary to a common impression, this transition has not been proceeding at a pace resembling the adoption of cellphones. In absolute terms, the world has been running into—not away from—carbon (see running into carbon, this page), and in relative terms our gains remain in single digits. The first United Nations Framework Convention on Climate Change was held in 1992. In that year, fossil fuels (using the conversion of fuels and electricity to a common denominator favored by BP in its annual statistical report) provided 86.6 percent of the wo...

Casual readers of the news get misled by the claimed advances of wind and solar electricity generation. Indeed, these renewable sources have been advancing steadily and impressively: in 1992 they supplied only 0.5 percent of the world’s electricity, and by 2017 they contributed 4.5 percent. But this means that, during those 25 years, more decarbonization of electricity generation was due to expanded hydroelectricity generation than to combined solar and wind installations. And because only about 27 percent of the world’s final energy consumption is electricity, these advances translate to a much smaller share of overall carbon reduction.

EV enthusiasts have also neglected to note the environmental consequences of mass-scale conversion to electric drive. If EVs are to reduce carbon emissions (and thus minimize the extent of global warming), their batteries must not be charged with electricity generated from the combustion of fossil fuels. But in 2020, just over 60 percent of global electricity will originate in fossil fuels; about 12 percent will come from wind and solar; and the rest from hydro energy and nuclear fission.

The UN’s Food and Agricultural Organization puts the annual global losses at 40–50 percent for root crops, fruits, and vegetables, 35 percent for fish, 30 percent for cereals, and 20 percent for oilseeds, meat, and dairy products. This means that, globally, at least one-third of all harvested food is wasted.

WRAP estimates that a dollar invested in food waste prevention has a 14-fold return in associated benefits.

In North America and Europe, about 60 percent of the total crop harvest is now destined for feeding—not directly for food.

The minimum water requirement per kilogram of boneless beef is, indeed, high, on the order of 15,000 liters, but only about half a liter of that ends up incorporated in the meat, with more than 99 percent being water needed for the growth of feed crops which eventually re-enters the atmosphere via evaporation and plant transpiration, and rains down.

In nutritional terms, the annual intake of 25–30 kilograms of edible meat would (assuming a 25 percent protein content) supply close to 20 grams of complete protein per day: 20 percent more than the recent mean, yet produced with greatly reduced environmental impact and providing all the health and longevity benefits of moderate carnivory.

The material’s environmental impact is another worry. Air pollution (fine dust) from cement production can be captured by fabric filters, but the industry (burning such inferior fuels as low-quality coal and petroleum coke) remains a significant source of carbon dioxide, emitting roughly a ton of the gas per ton of cement. For comparison, producing a ton of steel is associated with emissions of about 1.8 tons of CO2. Production of cement now accounts for about 5 percent of global CO2 emissions from fossil fuels, but its carbon footprint can be lowered by a variety of measures. Old concrete can be recycled, and the crushed material can be reused in construction. Blast furnace slag or fly ash captured in coal-fire power plants can replace some of the cement in mixing concrete. There are also several new low-carbon or no-carbon cement-making processes, but these alternatives will be making only small annual dents in a global output that is now surpassing 4 billion tons.

New cars thus weigh more than 180 times as much as all portable electronics, but require only seven times as much energy to make. And as surprising as that may be, we can make an even more startling comparison. Portable electronics don’t last long—on average, just two years—and so the world’s annual production of these devices embodies about 0.5 exajoules per year of use. Because passenger cars typically last for at least a decade, the world’s annual production embodies about 0.7 exajoules per year of use—which is only 40 percent more than portable electronic devices!

Both in the United States and in the European Union, buildings account for about 40 percent of total primary energy consumption (transportation comes second, at 28 percent in the US and about 22 percent in the EU). Heating and air conditioning account for half of residential consumption, which is why the single best thing we could do for the energy budget is to keep the heat in (or out) with better insulation.

The affluent world has used hundreds of billions of tons of it to create its high quality of life, but right now we do not have any affordable non-carbon alternatives that could be rapidly deployed on mass scales in order to energize the production of enormous quantities of what I have called the four pillars of modern civilization—ammonia, steel, cement, and plastics—which will be needed in Africa and Asia in the decades to come. The contrasts between the expressed concerns about global warming, the continued release of record volumes of carbon, and our capabilities to change that in the near term could not be starker.