The human race, Saul Griffith has estimated, currently consumes energy at an average rate of approximately 16 trillion watts, or sixteen terawatts—the equivalent of 160 billion hundred-watt lightbulbs burning all the time. Capping atmospheric greenhouse gas at 450 parts per million—a level that’s 15 percent higher than today’s and that

of each good, but it also makes those same goods cheaper and, ultimately, more plentiful and expendable, and all of that additional buying and selling makes us richer, and as we grow richer we have the means and the will to buy even more.

“frugality first induces efficiency second; efficiency first dissipates itself by making frugality appear less necessary. Frugality keeps the economy at a sustainable scale; efficiency of allocation helps us live better at any scale, but does not help us set the scale itself.” If we impose limits on our consumption of fossil fuels, advances in

Global Environmental Enemy No. 1 is the automobile, no matter what it runs on.

at the individual level, a meaningful response to environmental challenges consists of choices about what he calls “personal infrastructure”: “Which car? Which house? Which job (physical location in relation to the house)? Which large appliances? Which HVAC system? Which diet (vegetarian/omnivore)?

“Almost all of the arable land on Earth would need to be covered with the fastest-growing known energy crops, such as switchgrass, to produce the amount of energy currently consumed from fossil fuels annually.”

live smaller, live closer, and drive less.

as we’ve gotten better at making things, we’ve made more things.

don’t account for energy use and carbon emissions that have been not eliminated but merely exported out of the region under study—say, from California to a factory in China.