More thoughts on carbon capture

Analogies are risky things, but I think there’s a useful analogy between (1) the belief that global conservation is a sufficient antidote to rising atmospheric CO2 and (2) the belief that herd immunity is a sufficient antidote to pandemics.

Herd immunity is the model in which, as a deadly pathogen moves through the population, enough survivors with immunity will remain to attenuate further transmission, protecting uninfected individuals. The track record of herd immunity is well-known. A familiar example is the plague. In the absence of vaccination and antibiotics, a large fraction of the infected population died, while the survivors possessed immunity that protected the remaining people for a generation. The point here is that the price of herd immunity is enormous suffering and death. In the COVID pandemic, there were many ignorant folks who advocated for just letting herd immunity take care of it, rather than embracing masking, social distancing and vaccination. It’s one thing to take chances with your own life, but to impose the burdens of herd immunity needlessly on humanity is unconscionable.

Given enough time and loss of human life, it is plausible that reduced energy consumption alone could result in lowering atmospheric CO2 levels. Here’s how that will work: while the rate of CO2 accumulation would slow, the CO2 from previous anthropogenic activity won’t disperse fast enough to stop the increase. The resulting starvation for food and fresh water will drive global violence as people displaced by flooding, desertification, inhospitable temperatures and resource depletion try to wrest resources from the remaining parts of the planet. Billions of deaths from starvation, violence and increased infectious disease will result in an eventual “herd immunity” from global CO2 levels for the few survivors. Again, at the unconscionable price of enormous suffering and death.

The realistic alternatives to herd immunity to infectious disease are technological fixes: antibiotics and vaccines. The realistic alternatives to global warming are also technological: carbon capture or solar geoengineering. As with all technological fixes, there are side effects and risks. But rolling the dice on climate change for fear of these hypothetical risks (or worse yet, glib cynicism about science and technology) dooms huge numbers of people to avoidable suffering.

Reversing climate change with geoengineering