Energy and Human Ambitions on a Finite Planet, 2021a

3 Population 39
4
Niger
Population Growth Rate (%)
3
2
1
0
−1
Pakistan
India
Nigeria
Egypt
Iran
Indonesia
Brazil
Mexico
China
Russia
Saudi Arabia
Italy Germany
Japan
1000 10000 100000
Per Capita GDP ($)
USA
Figure 3.10: Net population rate, in percent,
as a function of per-capita GDP. A
clear trend shows wealthier countries having
lower growth rates. A win–win solution
would seem to present itself, in which everyone
arrives at the lower right-h<strong>and</strong> side of
this graph: more money for all <strong>and</strong> a stable
population! Dot size (area) is proportional
to population [6, 8, 19, 20].
Example 3.3.1 The U.S. has a birth rate of about 12 people per 1,000
per year, <strong>and</strong> a death rate of 8.1 people per 1,000 per year. The net rate
is then roughly +4 per 1,000 per year, translating to 0.4% net growth. 18
Niger has a birth rate of 46 per 1,000 per year <strong>and</strong> a death rate of 11,
resulting in a net of positive 35, or 3.5%.
As conditions change, birth <strong>and</strong> death rates need not change in lock-step.
Developed countries tend to have low birth rates <strong>and</strong> low death rates,
balancing to a relatively low net population growth rate. Developing
countries tend to have high death rates <strong>and</strong> even higher birth rates,
leading to large net growth rates. Figure 3.11 depicts both birth rates <strong>and</strong>
death rates for the countries of the world. A few countries (mostly in
Europe) have slipped below the replacement line, indicating declining
population. 19
The general sense is that developed countries have “made it” to a responsible
low-growth condition, <strong>and</strong> that population growth is driven by
poorer countries. An attractive solution to many 20 is to bring developing
countries up to developed-country st<strong>and</strong>ards so that they, too, can settle
into a low growth rate. This evolution from a fast-growing poor country
to a slow (or zero) growth well-off country is called the demographic
transition.
18: 4 per 1,000 is 0.4 per 100, which is another
way to say 0.4 percent.
19: Note that immigration is not considered
here: just birth rate <strong>and</strong> death rate within
the country.
20: . . . but unsolicited “preaching” to others
Definition 3.3.2 The demographic transition refers to the process by
which developing countries having high death rates <strong>and</strong> high birth rates adopt
technologies, education, <strong>and</strong> higher st<strong>and</strong>ards of living that result in low
death rates <strong>and</strong> low birth rates, more like advanced countries.
In order to accomplish this goal, reduced death rates are facilitated by
© 2021 T. W. Murphy, Jr.; Creative Commons Attribution-NonCommercial 4.0 International Lic.;
Freely available at: https://escholarship.org/uc/energy_ambitions.