How the World Really Works: A Scientist’s Guide to Our Past, Present and Future

by Vaclav Smil

electricity still supplies only a relatively small share of final global energy consumption, just 18 percent.

ignoring the huge gap between the energy density of kerosene burned by turbofans and today’s best lithium-ion (Li-ion) batteries that would be on board these hypothetically electric planes.

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

Growing the grain, milling it, and baking a 1-kilogram sourdough loaf thus requires an energy input equivalent of at least 250 milliliters of diesel fuel, a volume slightly larger than the American measuring cup.