Energy and Human Ambitions on a Finite Planet, 2021a

3 Population 52
22. The set of diagrams below show five different time sequences
on the left akin to Figure 3.16, labeled 1–5. The first four on the
left have increasing τ (delay until birth rate begins falling), <strong>and</strong>
the last increases birth rate before falling again. On the right
are five trajectories in the birth/death rate space (like Figure
3.12), scrambled into a different order <strong>and</strong> labeled A–E. 42 Deduce 42: Note that figures A. <strong>and</strong> E. differ only
how the corresponding trajectory for each time sequence would
appear in the birth/death rate plot on the right, matching letters
to numbers for all five.
by whether the transition pauses (dwells)
at the corner for some time.
1.
death rate
rate
time
birth rate
A.
birth rate
dwell
death rate
2.
death rate
rate
time
birth rate
B.
birth rate
death rate
3.
death rate
rate
time
birth rate
C.
birth rate
death rate
birth rate
4.
death rate
rate
time
D.
birth rate
death rate
birth rate
5.
rate
death rate
time
E.
birth rate
no dwell
death rate
23. Referring to the figures for Problem 22 (<strong>and</strong> described within the
same problem), which pair 43 corresponds to the largest population
surge, <strong>and</strong> which pair produces the smallest? Explain your
reasoning, consistent with the presentation in the text.
24. Referring to the figures for Problem 22 (<strong>and</strong> described within the
same problem), which pair 44 is most similar to the actual trajectory
we witness (i.e., Figure 3.11), <strong>and</strong> what does this say about the
43: . . . number <strong>and</strong> associated letter; not
necessarily arranged next to each other
44: . . . number <strong>and</strong> associated letter; not
necessarily arranged next to each other
© 2021 T. W. Murphy, Jr.; Creative Commons Attribution-NonCommercial 4.0 International Lic.;
Freely available at: https://escholarship.org/uc/energy_ambitions.