Geoscience Reference
In-Depth Information
Health of
economy or
ecosystem
Health of
economy or
ecosystem
Stresses from climate
change, pollution,
and deforestation
push on system
Original
good
equilibrium
(a)
(b)
T
T
Health of
economy or
ecosystem
Health of
economy or
ecosystem
Further stresses push
system past tipping point,
and system rushes to new
bad equilibrium
(c)
(d)
System ends in locally stable
“bad equilibrium”
T
T
Figure 11.
Tipping points: moving from a good to a bad equilibrium. The double-
bottomed bowl illustrates how stresses can change a system slowly until a tipping point
is reached, after which there are rapid and potentially catastrophic changes. Note that
there are two equilibria—a good equilibrium in (a), and a bad equilibrium in (d).
fi nancial system) pushes the right side of the bowl downward. If the
stresses are mild, the ball moves only a little, and when the stresses
stop, it rolls back to where it started, back to panel (a).
But if the stresses are only a little larger, the tipping point is
reached, and the ball races to the bottom of the second curve, as shown
in panel (c). This new position is a “bad equilibrium” because it has
undesirable properties. The bad property might be ruined banks, nu-
clear meltdowns, or melted ice caps. The problem is that the ball stays
in the bad equilibrium. Once the ball is in the bad equilibrium, even
when the stresses are removed, the ball is stuck in the bad equilibrium
shown in panel (d). This system turns out to have multiple locally sta-
