An asteroid in a bathtub wrapped in an enigma—is that clear?

Having grown up neither British nor celebrating Christmas—and thus without any firsthand experience of plum pudding—I didn’t find it particularly enlightening to learn, in 8th grade chemistry class, that the turn-of-the-century conception of the atom was akin to this fruited, brandied, yuletide delicacy. Surely this metaphor of bits of dried fruit suspended in crumbly pudding meant something real and tangible to someone, but not me. Yet lessons of science must be communicated thus—through metaphor—because, while plum pudding isn’t rich with meaning for everyone, nobody can see atoms with the naked eye either.

The same holds for climate change. We need to understand it in terms of something we can see, someone we can talk to, somewhere we can stand, or something we can—literally—sink our teeth into. And, as with the atom-as-plum-pudding pedagogical tool, important details can get lost in the process.

I have often (as in the work of economist William Nordhaus) seen the climate threat explained as an asteroid hurtling toward the Earth, with major impacts but of uncertain scale and uncertain timing. A recent article in TIME, written for a general audience, also suggests that tipping points or thresholds—when things get really bad, really fast, as in the possible collapse of the Greenland or West Antarctic ice sheets and the resulting multi-meter sea-level rise—and the uncertainty about them are like an asteroid hitting the Earth:
 

“For the lay person, then, perhaps the simplest way to understand it is to imagine a distant asteroid, somewhere out in space, on a collision course with Earth. It's not clear when or where the asteroid will hit, or exactly how severe the consequences will be. But it is clear that when it happens, the consequences will be far worse — and last far longer — than any natural disaster humanity has ever known.”

The article goes on to point out that this very uncertainty prevents many from storming the barricades.  Well, if I thought catastrophic climate impacts would be like the result of an asteroid, I might be a bit nonchalant too. Frankly, an asteroid has nothing to do with me.  It’s not my fault.  And I won’t notice the impacts of a collision until it happens.

The trouble with conceptualizing the climate change problem and solutions is that it has so many dimensions.

The emissions of CO2 into the atmosphere, absorption of some CO2 by carbon sinks such as vegetation, and resulting net change in the atmospheric concentration can be explained with some basic plumbing, in terms of a faucet (the emissions), a drain (the vegetation etc.), and a bathtub (the atmosphere).

The trace that people leave by their consumption of fossil fuels (and products made using fossil fuels), and contributions to land-use change and deforestation, can be explained as a footprint.

But how can these ideas connect?  The idea of a footprint making a bathtub overflow—well, that’s no more elucidating than an atom-as-plum-pudding.

I can readily accept that an overarching metaphor that captures more aspects of the problem would no longer be tractable.  But while we’re on the subject, I do yearn for one that would also tell us more about the solutions and opportunities.