Solar geoengineering refers to putting stuff in the atmosphere that would have the effect of counteracting greenhouse gases. Yes, there would be risks in undertaking geoengineering. However, those who argue that substantial dangers of climate change are fairly near-term must be willing to consider potentially unpleasant answers. Even if the risks of geoengineering are too substantial right now, given the present state of climate change, if the world as a whole doesn\’t move forward with steps to hold down emissions of greenhouse gases, then perhaps the risks of geoengineering will look more acceptable in a decade or two?
- Both unchecked climate change and any potential deployment of solar geoengineering (SG) are governed by processes that are currently unknowable; i.e., either is afflicted with ignorance.
- Risk, uncertainty, and ignorance are often greeted with the precautionary principle: “do not proceed.” Such inertia helps politicians and bureaucrats avoid blame. However, the future of the planet is too important a consequence to leave to knee-jerk caution and strategic blame avoidance. Rational decision requires the equal weighting of errors of commission and omission.
- Significant temperature increase, at least to the 2°C level, is almost certainly in our planet’s future. This makes research on SG a prudent priority, with experimentation to follow, barring red-light findings. …
Consider the decision of whether to enroll in a high-risk medical trial. Faced with a bad case of cancer, the standard treatment is high-dose chemotherapy. Now consider as an alternative treatment an experimental bone-marrow transplant. the additional treatment mortality of the trial, of say 4 percentage points, is surely an important aspect of the decision – but so should be the gain in long-run survival probability. If that estimated gain is greater than 4 percentage points, say 10 or even “only” 6 percentage points, a decision maker with the rational goal of maximizing the likelihood of survival should opt for the experimental treatment.
All too often, however, psychology intervenes, including that of doctors. Errors of commission get weighted more heavily; expected lives are sacrificed. The Hippocratic Oath bans the intention of harm, not its possibility. Its common misinterpretation of “first do no harm” enshrines the bias of overweighing errors of commission. To be sure, errors of commission incur greater blame or self-blame than those of omission when something bad happens, a major source of their greater weight. But blame is surely small potatoes relative to survival, whether of a patient or of the Earth. Hence, we assert once again, italics and all: Where climate change and solar geoengineering are concerned, errors of commission and omission should be weighted equally.
That also implies that the dangers of SG [solar geoengineering] – and they are real – should be weighed objectively and dispassionately on an equal basis against the dangers of an unmitigated climate path for planet Earth. The precautionary principle, however tempting to invoke, makes little sense in this context. It would be akin to suffering chronic kidney disease, and being on the path to renal failure, yet refusing a new treatment that has had short-run success, because it could have long-term serious side effects that tests to date have been unable to discover. Failure to assiduously research geoengineering and, positing no red-light findings, to experiment with it would be to allow rising temperatures to go unchecked, despite great uncertainties about their destinations and dangers. That is hardly a path of caution.
For an earlier post on this topic, see \”Geoengineering: Forced Upon Us?\” (May 11, 2015).