For years, I've used the metaphor of lifestyle diseases -- obesity, diabetes, heart disease -- to help students understand that seemingly desirable behaviors, when taken to excess, can lead to negative and entirely unintended consequences. Eat too much, enjoy too much leisure, degrade a system -- your body -- that evolved to prosper under circumstances of scarce food and regular exertion. As a metaphor, it's served to help students understand that seemingly desirable social behaviors like production, consumption and energy (particularly, fossil energy) utilization can degrade a climate system that served humanity well under circumstances of minimal resource utilization and long-term carbon (coal, oil) sequestration.
But now it seems that there may be a more material relationship between climate instability and lifestyle diseases. The evidence is still characterized as speculative, but the logic seems fairly straightforward: climate instability reduces agricultural production, reduced food production leads to food shortages, food shortages lead to degraded diets, low-grade diets correlate with high incidence of obesity, diabetes and heart disease. The logical chain is explained in this article from Grist, based on this series of letters in the American Journal of Public Health.
Of course, the logic detailed is based -- as deductive logic always is -- on a set of assumptions. Perhaps the key assumption is that systems of food production and consumption stay pretty much as they are, at least in developed countries. Stated another way, the assumption is that as preferable industrially-produced food becomes less available and more expensive, families will shift their consumption choices to lower-quality foods that are still industrially produced. In a society where most families are quite divorced from the processes and the knowledge by which their food is produced, perhaps that assumption is valid. But given appropriate knowledge, many families -- certainly, many communities -- have the physical wherewithal to grow a significant portion of their own food and thereby mitigate, if not totally eliminate, the impacts of reduced yield from industrial agriculture.
Perhaps this is the new metaphor -- indeed, the new challenge for the education system. What's true, and fairly easily understood, for food production (after all, it's not much of a stretch to understand that a plot of land now being used as lawn could easily be repurposed as kitchen garden) is also true (if less easily so) for production of life's other necessities.
Climate instability may well already be baked into the biophysical system that all of us inhabit. But a resulting degradation of lifestyle and physical health needn't necessarily follow. Resilience consists in being able to adapt to changing circumstances, predictable or otherwise. Ability to adapt depends, of course, on a willingness to adapt and -- logically prior to willingness -- on an ability to conceive of an alternative. If the ultimate objective of higher education is to develop a capacity for critical thinking, that ability to conceive of an alternative is a fitting success criterion.
Of course, the path to success probably involves a change in diet. And exercise.