You really do have to wonder whether a few years from now we’ll look back at the first decade of the 21st century — when food prices spiked, energy prices soared, world population surged, tornados plowed through cities, floods and droughts set records, populations were displaced and governments were threatened by the confluence of it all — and ask ourselves: What were we thinking? How did we not panic when the evidence was so obvious that we’d crossed some growth/climate/natural resource/population redlines all at once?
Gilding cites the work of the Global Footprint Network, an alliance of scientists, which calculates how many “planet Earths” we need to sustain our current growth rates. G.F.N. measures how much land and water area we need to produce the resources we consume and absorb our waste, using prevailing technology. On the whole, says G.F.N., we are currently growing at a rate that is using up the Earth’s resources far faster than they can be sustainably replenished, so we are eating into the future. Right now, global growth is using about 1.5 Earths. “Having only one planet makes this a rather significant problem,” says Gilding.
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.”