How the World Really Works: The Science Behind How We Got Here and Where We're Going

by Vaclav Smil

the four pillars of modern civilization: ammonia, steel, concrete, and plastics.

In contrast, electricity is intangible and we can’t get an intuitive sense of it in the same way as we do with fuels.

In two centuries, the human labor to produce a kilogram of American wheat was reduced from 10 minutes to less than two seconds.

I have chosen three of them to use as examples, and I picked them because of their nutritional dominance. Bread has been the staple of European civilization for millennia. Given the religious proscriptions on the consumption of pork and beef, chicken is the only universally favored meat. And no other vegetable (although botanically a fruit) surpasses the annual production of tomatoes, now grown not only as a field crop but increasingly in plastic or glass greenhouses.

The US Department of Agriculture publishes statistics on the annual feeding efficiency of domestic animals, and over the past five decades these ratios (units of feed expressed in terms of corn grain per unit of live weight) show no downward trends for either beef or pork, but impressive gains for chicken.[29]

This helps to explain the rapid rise of chicken to become the dominant meat in all Western countries (globally, pork still leads, thanks to China’s enormous demand).

Tomatoes can be grown anywhere with at least 90 days of warm weather,

but the best nutritional advice is that we do not have to eat more than an adult’s body mass equivalent in meat per year to obtain an adequate amount of high-quality protein.[73]

In 2019, the world consumed about 4.5 billion tons of cement, 1.8 billion tons of steel, 370 million tons of plastics, and 150 million tons of ammonia, and they are not readily replaceable by other materials—certainly not in the near future or on a global scale.[5]

The Earth’s atmosphere absorbs the incoming (short-wave) solar radiation and radiates (longer waves) to space. Without it, the temperature of the Earth would be -18°C, and hence our planet’s surface would be perpetually frozen. Trace gases change the planet’s radiation balance by absorbing some of the outgoing (infrared) radiation and raising the surface temperature.

In this regard, media reports about “land-less” urban agriculture—hydroponic cultivation in high-rises—are particularly devoid of any real understanding of global food demand. Such high-input operations can produce leafy greens (lettuces, basil) and some vegetables (tomatoes, peppers) whose nutritional value is almost solely in their vitamin C content and roughage.[30]