Until the early1960s, humanity consumed less than half of the world’s usable renewable resources. By 1990 we were consuming all of them, even though the amount available was growing at a modest pace. The gluttony continued as we began processing non-renewable resources, now equivalent to more than 40 percent of the renewable resource base. Our population growth is beginning to slow due to this new reality, and in little more than a dozen years will likely stop altogether. Beyond that, more people will die than are born to replace them, the population dropping about as fast as it increased so that the rise in the per capita consumption can follow its present course. By the 2130s the non-renewable resources will be gone and the remaining quarter of what the population was at its peak will fight over the renewable resources, barely able to replace the dead with those who are born so they can sustain a standard of living less than triple what we enjoy today. This is the story my population-consumption model tells about our history and our likely future. The history is accurate, while the future is in the process of being tested.
Of all the variables that are likely to cause the cresting and decline of the world’s population, per capita consumption seems to be the most influential. Even if we could get our hands on more non-renewable resources, we would need to limit its growth in order to maximize the number of people living as well as possible into the far future. If there should be one focus in keeping the worst from happening, this is it; unfortunately, it may also be the most difficult.
Averaging its oscillations, per capita consumption has been growing at about 0.9 percent per year (it is likely to slow to no less than 0.8 percent per year, even during the projected population decline). For a person spending $40,000 per year this would be roughly equivalent to spending an additional $350 the following year (using the actual number). What would it take to get everyone in the world now and in the future to give up on such an increase, or to spend it on additional renewable resources?