Numbers Don't Lie: 71 Things You Need to Know About the World

by Vaclav Smil

The replacement level of fertility is that which maintains a population at a stable level. It is about 2.1, with the additional fraction needed to make up for girls who will not survive into fertile age. No country has been able to stop the fertility decline at the replacement level and achieve a stationary population. An increasing share of humanity lives in societies with below-replacement fertility levels. In 1950, 40 percent of humanity lived in countries with fertilities above 6 and the mean rate was about 5; by the year 2000, just 5 percent of the global population was in countries with fertilities above 6, and the mean (2.6) was close to the replacement level. By 2050, nearly three-quarters of humanity will reside in countries with below-replacement fertility. This nearly global shift has had enormous demographic, economic, and strategic implications. European importance has diminished (in 1900 the continent had about 18 percent of the world’s population; in 2020 it has only 9.5 percent) and Asia has ascended (60 percent of the world total in 2020), but regional high fertilities guarantee that nearly 75 percent of all births during the 50 years between 2020 and 2070 will be in Africa.

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 speed of intercontinental travel rose from about 35 kilometers per hour for large ocean liners in 1900 to 885 km/h for the Boeing 707 in 1958, an average rise of 5.6 percent a year. But speed of jetliners has remained essentially constant ever since—the Boeing 787 cruises just a few percent faster than the 707. Between 1973 and 2014, the fuel-conversion efficiency of new US passenger cars (even after excluding monstrous SUVs and pickups) rose at an annual rate of just 2.5 percent, from 13.5 to 37 miles per gallon (that’s from 17.4 to 6.4 liters per 100 kilometers). And finally, the energy cost of steel (coke, natural gas, and electricity), our civilization’s most essential metal, was reduced from about 50 gigajoules per ton to less than 20 between 1950 and 2010—that is, an annual rate of about –1.7 percent. 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.

This uncritical genuflection before the altar of innovation is wrong on two counts: It ignores those big, fundamental quests that have failed after spending huge sums on research. And it has little to say about why we so often stick to an inferior practice even when we know there’s a superior course of action. The fast breeder reactor, so called because it produces more nuclear fuel than it consumes, is one of the most remarkable examples of a prolonged and costly innovation failure. In 1974, General Electric predicted that by 2000 about 90 percent of the United States’ electricity would come from fast breeders. GE was merely reflecting a widespread expectation: during the 1970s, the governments of France, Japan, the Soviet Union, the United Kingdom, and the United States were all investing heavily in the development of breeders. But high costs, technical problems, and environmental concerns led to shutdowns of British, French, Japanese, American (and also smaller German and Italian) programs, while China, India, Japan, and Russia are still operating experimental reactors. After the world as a whole spent well above $100 billion in today’s money over some six decades of effort, there has been no real commercial payoff.

And why do we measure the progress of economies by gross domestic product? GDP is simply the total annual value of all goods and services transacted in a country. It rises not only when lives get better and economies progress but also when bad things happen to people or to the environment. Higher alcohol sales, more driving under the influence, more accidents, more emergency-room admissions, more injuries, more people in jail—GDP goes up. More illegal logging in the tropics, more deforestation and biodiversity loss, higher timber sales—again, GDP goes up. We know better, but we still worship high annual GDP growth rate, regardless of where it comes from.

There are many things we could do—above all, use better reactor designs and act resolutely on waste storage—to generate a significant share of electricity from nuclear fission and so limit carbon emissions. But that would require an unbiased examination of the facts, and a truly long-range approach to global energy policy. I see no real signs of either.

Assuming a wind velocity of 12 meters per second and an energy conversion coefficient of 0.4, then a 100-megawatt turbine would require rotors nearly 550 meters in diameter. To predict when we’ll get such a machine, just answer this question: When will we be able to produce 275-meter blades of plastic composites and balsa, figure out their transport and their coupling to nacelles hanging 300 meters above the ground, ensure their survival in cyclonic winds, and guarantee their reliable operation for at least 15 or 20 years? Not soon.

Just about everything you wear or use around the house once sat in steel boxes on ships whose diesel engines propelled them from Asia, emitting particulates and carbon dioxide. Surely, you would think, we can do better.

The conclusion is obvious. To have an electric ship whose batteries and motors weighed no more than the fuel (about 5,000 tons) and the diesel engine (about 2,000 tons) in today’s large container vessels, we would need batteries with an energy density more than 10 times as high as today’s best Li-ion units. But that’s a tall order indeed: in the past 70 years, the energy density of the best commercial batteries hasn’t even quadrupled.

When adjusted for inflation (and expressed in constant 2019 monies), the average price of US residential electricity fell from $4.81 per kilowatt-hour in 1902 (the first year for which the national mean is available) to 30.5 cents in 1950, then to 12.2 cents in 2000; and in early 2019 it was just marginally higher, at 12.7 cents/kWh. This represents a relative decline of more than 97 percent—or, stated in reverse, a dollar now buys nearly 38 times more electricity than it did in 1902. But, during that period, average (again, inflation-adjusted) manufacturing wages nearly sextupled, which means that in a blue-collar household, electricity is now more than 200 times more affordable (its effective earning-adjusted cost is less than 0.5 percent of the 1902 rate) than it was almost 120 years ago.

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 world’s primary energy. By 2017, they supplied 85.1 percent, a reduction of a mere 1.5 percent in 25 years. This key indicator of the global energy transition pace is perhaps the most convincing reminder of the world’s continued fundamental dependence on fossil carbon. Can a marginal slip of 1.5 percent in a quarter-century be followed in the coming 25–30 years with the substitution of some 80 percent of the world’s primary energy for non-carbon alternatives, in order to come close to zero fossil carbon by 2050? Business as usual will not get us there, and the only plausible scenarios to do so are either a collapse of the global economy or the adoption of new energy sources at a pace and on a scale far beyond our immediate capabilities.

Here, in ascending order, are a few of the weight ratios that a 70-kilogram passenger can achieve: 0.1 for a 7-kilogram bicycle 1.6 for Italy’s 110-kilogram Vespa scooter 5 or less for a modern bus, and that’s just if you count sitting passengers 7.3 for France’s 510-kilogram Citroën 2CV (deux chevaux, or “two horses”), back in the 1950s 7.7 for the Ford Model T introduced in 1908 and also for Japan’s shinkansen rapid train that began to run in October 1964 (the train’s frugal ratio owes as much to design as it does to a high ridership rate) 12 for a Smart car, 16 for a Mini Cooper, 18 for my own Honda Civic LX, 20 and change for the Toyota Camry 26 for the average American light-duty vehicle in 2013 28 for the BMW 740i 32 for the Ford F-150, the bestselling American vehicle 39 for the Cadillac Escalade EXT.

As a global mean, more than three-fifths of the electricity for an EV still comes from fossil carbon, but that fraction varies widely among countries and within them. EVs in my home province of Manitoba, Canada (where more than 99 percent of all electricity comes from large hydro stations) are clean hydro cars. Quebec, Canada (about 97 percent hydro) and Norway (about 95 percent hydro) come close to that. French EVs are largely nuclear-fission cars (the country gets some 75 percent of its electricity from fission). But in most of India (particularly Uttar Pradesh), China (particularly Shaanxi province), and Poland, EVs are overwhelmingly coal cars. The last thing we need is to push for the rapid introduction of a source of demand that would summon even more fossil fuel–based electricity generation. And even if EVs all ran on renewable sources of electricity, greenhouse gases would still be emitted during the production of cement and steel for hydroelectric dams, wind turbines, and photovoltaic panels, and of course during the manufacture of the cars themselves (see WHAT’S WORSE FOR THE ENVIRONMENT—YOUR CAR OR YOUR PHONE?, p. 287).

In 2017, so far the safest year in commercial flying, domestic and international flights carried 4.1 billion people and logged 7.69 trillion passenger-kilometers, with only 50 fatalities. With the mean flight time at about 2.2 hours, this implies roughly 9 billion passenger-hours, and 5.6 × 10–9 fatalities per person per hour in the air. But how low is this risk? The obvious measuring stick is general mortality—the annual death rate per 1,000 people. In affluent nations that rate now ranges between 7 and 11; I will use 9 as the mean. Because the year has 8,760 hours, this average mortality prorates to 0.000001 or 1 × 10–6 deaths per person per hour of living. This means that the average additional chance of dying while flying is just 5/1,000th of the risk of simply being alive. Smoking risks are 100 times as high; ditto for driving in a car. In short, flying has never been safer.

In addition, broilers have been bred to mature faster and to put on an unprecedented amount of meat. Traditional free-running birds were slaughtered at the age of one, when they weighed only about 1 kilogram. The average weight of American broilers rose from 1.1 kilograms in 1925 to nearly 2.7 in 2018, while the typical feeding span was cut from 112 days in 1925 to just 47 days in 2018. Consumers benefit while the birds suffer. They gain weight so rapidly because they can eat as much as they want while being kept in darkness and strict confinement. Because consumers prefer lean breast meat, the selection for excessively large breasts shifts the bird’s center of gravity forward, impairs its natural movement, and puts stress on its legs and heart. But the bird cannot move anyway; according to the National Chicken Council, a broiler is allotted just 560–650 square centimeters, an area only slightly larger than a sheet of standard A4 letter paper. As long periods of darkness improve growth, broilers mature under light intensities resembling twilight. This condition disrupts their normal circadian and behavioral rhythms. On one side, you have shortened lives (less than seven weeks for a bird whose normal lifespan is up to eight years) and malformed bodies in dark confinement; on the other, in late 2019 you got retail prices of about $2.94 per pound ($6.47/kg) for boneless breast, compared with $4.98/lb for round beef roast and $8.22/lb for choice sirloin steak.

In North America and Europe, about 60 percent of the total crop harvest is now destined for feeding—not directly for food. This, of course, has major environmental consequences, particularly due to the need for nitrogen fertilizers and water. At the same time, citing the large volumes of water needed to produce feed for cattle is quite misleading. 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.

But these two relatively low intakes are a part of what I see as by far the most important explanatory factor, as Japan’s true exceptionalism: the country’s remarkably moderate average per capita food supply. While food balance sheets of virtually all affluent Western nations (be it the US or Spain, France or Germany) show a daily availability of 3,400–4,000 kilocalories per capita, the Japanese rate is now below 2,700 kilocalories, roughly 25 percent lower. Of course, actual average consumption cannot be at a 3,500-kilocalorie-per-day level (only hard-working, big-stature men might need that much), but even after an indefensibly high share of food waste, this high supply translates into excessive eating (and obesity). In contrast, studies of actual food intakes show that the Japanese daily mean is now below 1,900 kilocalories, commensurate with age distribution and physical activity of the aging Japanese population. This means that perhaps the single most important explanation of Japan’s longevity primacy is quite simple: moderate overall food consumption, the habit expressed in just four kanji characters, 腹八分目 (hara hachi bun me, “belly eight parts [in ten] full”)—an ancient Confucian precept, and hence yet another import from China. But the Japanese, unlike the banqueting and food-wasting Chinese, actually do practice it.

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.

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! I hasten to add that these are, necessarily, only highly approximate calculations—but even if these rough aggregates were to err in opposite directions (that is, if car-making actually embodies more energy than calculated, and electronic production needs less), the global totals would still be surprisingly similar, with the most likely difference no greater than twofold. And looking ahead, the two aggregates might get even closer: annual sales of both cars and mobile devices have been recently slowing, but the future looks less promising for internal combustion engines. Of course, operating energy costs of the two classes of these highly energy-intensive devices are vastly different. A compact American passenger car consumes about 500 gigajoules of gasoline during a decade of its service, five times its embodied energy cost. A smartphone consumes just 4 kilowatt-hours of electricity annually and less than 30 megajoules during its two years of service—or just 3 percent of its embodied energy cost if the electricity comes from a wind turbine or from a photovoltaic cell. That fraction rises to about 8 percent if the en...

Once energy prices began to rise and more rational building codes came into effect in North America, it became compulsory to incorporate plastic barriers and fiberglass batts—pillow-like rolls that can be packed between the wooden frames or studs. Higher overall R-values were easily achieved by using wider studs (two-by-six) or, better yet, by double-studding, which involves building a sandwich from two frames, each one filled with insulation. (In North America, a softwood “two-by-six” is actually 1.5 by 5.5 inches, or 38 by 140 millimeters.) For a well-built North American wall this means adding insulation values of drywall (0.5), polyethylene vapor barrier (0.8), fiberglass batts (20), fiberboard sheathing (1.3), plastic house wrap (Tyvek ThermaWrap at 5), and beveled wood cladding (0.8). Adding the insulating value of interior air film brings the total R-value to about 29. Brick walls, too, got better. To keep a desired outer look of colored brick, an old wall can be retrofitted from the inside by putting wooden battens (thin strips that hold insulation in place) on the interior plaster and attaching insulation-backed gypsum board integrated with a vapor membrane to keep out moisture. With 2-inch insulated plasterboard, this will triple the previous overall R-value, but even so, the insulated old brick wall will remain an order of magnitude behind the two-by-six framed North American wall. Even people who are generally aware of R-values do not expect to see such a large...

That’s a loss reduction of up to 90 percent compared to a single pane. In the world of energy savings, there are no other opportunities of that magnitude applicable on a scale of billions of units. Bonus point: it would actually work. And there is also a comfort factor. With the outdoor temperature at –18°C (common January overnight lows in Edmonton, Alberta, or daily highs in Russia’s Novosibirsk) and the indoor temperature at 21°C, the internal surface temperature of a single-pane window is around 1°C, an older double-pane window will register 11°C, and the best triple-glazed window 18°C. At that temperature, you can sit right next to it. And triple-paned windows have the added advantage of reducing condensation on the interior glass by raising its temperature above the dew point. Such windows are already common in Sweden and Norway, but in Canada (with its low-cost natural gas) they may not be mandated before 2030, and as in many other cold-weather jurisdictions, the required standard is still equivalent to just a double-glazed window with one low-emissivity coating.

The Paris Agreement of 2015 was lauded as the first accord containing specific national commitments to reduce future emissions. But actually, only a small number of countries made specific promises, there is no binding enforcement mechanism, and even if all those targets were met by 2030, carbon emissions would still rise to nearly 50 percent above the 2017 level. According to the 2018 study by the Intergovernmental Panel for Climate Change, the only way to keep the average world temperature rise to no more than 1.5°C would be to put emissions almost immediately into a decline steep enough to bring them to zero by 2050. That is not impossible—but it is very unlikely. Reaching that goal would require nothing short of a fundamental transformation of the global economy on scales and at a speed unprecedented in human history, a task that would be impossible to do without major economic and social dislocations. The greatest challenge would be how to lift billions from poverty without relying on fossil carbon. 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 concer...