This is not science fiction. This is what happens when our system of growth and the system of nature hit the wall at once. While in Yemen last year, I saw a tanker truck delivering water in the capital, Sana. Why? Because Sana could be the first big city in the world to run out of water, within a decade. That is what happens when one generation in one country lives at 150 percent of sustainable capacity.
“If you cut down more trees than you grow, you run out of trees,” writes Gilding. “If you put additional nitrogen into a water system, you change the type and quantity of life that water can support. If you thicken the Earth’s CO2 blanket, the Earth gets warmer. If you do all these and many more things at once, you change the way the whole system of planet Earth behaves, with social, economic, and life support impacts. This is not speculation; this is high school science.”