Reporting for the USA in 1996, The President's Council on Sustainable Development concluded that the efficiency in the use of all resources would have to increase by more than fifty percent over the next four or five decades just to keep pace with population growth.
Within the third world, population growth rates are expected to remain high (3.2% a year) in West Asia and to continue to accelerate (to 3.3% a year) in sub-Saharan Africa. Elsewhere they should fall, sometimes sharply. It is perhaps too early to claim that the population problem has been solved, but attention in future is likely to be focused less on the overall rate of increase and more on the rate of increase in urban areas, which continues to be high despite the diminished overall rate of population growth. In 1980-1985, for instance, the urban population grew 3.1% a year in the low-income economies and 3.7% a year in the middle-income economies, as compared to total population growth rates in the two groups of countries of 1.9 and 2.3%, respectively.
2. Standards of living have risen all over the world even as population has grown. The most important benefit, in fact, that population growth bestows on an economy is to increase the stock of useful knowledge. The ultimate resource is people -- skilled, spirited, and hopeful people who will exert their wills and imaginations for their own benefit, and so, inevitably, for the benefit of us all. More people generate more progress. Take agriculture as an example: the first farmers were slash-and-burn cultivators, who might farm a plot for a year or two and then move on, not returning for maybe two decades. As the population grew, however, they had to return more frequently to the same plot. That meant problems: compacted, depleted, weed-infested soils. But those new problems meant new solutions: hoes, manure, compost, crop rotation, irrigation. Even in this century necessity-induced invention has meant that intensive systems of agriculture replaced extensive systems, accelerating the rate of food production.
2. If the only ultimate check on the growth of population is misery, then the population will grow until it is miserable enough to stop its growth. (Boulding's First Theorem: "The Dismal Theorem").
Any technical improvement can only relieve misery for a while, for so long as misery is the only check on population, the [technical] improvement will enable population to grow, and will soon enable more people to live in misery than before. The final result of technical improvements, therefore, is to increase the equilibrium population which is to increase the total sum of human misery. (Boulding's Second Theorem: "The Utterly Dismal Theorem").
If something else, other then misery and starvation, can be found which will keep a prosperous population in check, the population does not have to grow until it is miserable and starves, and it can be stably prosperous. (Boulding's Third Theorem: "The moderately cheerful form of the Dismal Theorem").
Until we know more, a "Cheerful Theorem" remains a question mark. Misery we know will do the trick. This is the only sure-fire automatic method of bringing population to an equilibrium. Other things may do it.