Inhabitat ran a post last week entitled “5 Crazy Ways to Stop Climate Change with Geoengineering.” Some of the entries were knowingly silly (see number five: a $350 trillion lens to be built in space, for example), but others seem like the kind of thing a certain kind of politician might get behind. Dealing with our problems via a single grand gesture has a kind of appeal, but most scientists shake their heads at these kinds of solutions. Why is that?

There’s an old short story called “Watchbird” by Robert Sheckley. The heroes of his story succeed in creating a law-enforcing drone that is able to detect the particular physiological activity of an individual intent on violence against another human being and to disable an attacker. These birds quickly put police homicide departments out of business, wheeling above in the sky, ready to swoop at a moment’s notice on those with criminal intent.

Of course, things soon go wrong. The watchbirds begin attacking fishermen (to rescue the fish), farmers (to prevent violence to the produce and grain) and even surgeons (who appeared to be attacking people with sharp implements). Because they’re autonomous, the watchbirds cannot be stopped. The only option seems to be waiting for them to wear out. Somebody then has the bright idea of creating “hawks” to stop the watchbirds; stronger, faster, more powerful. Towards the end of the story we see that the hawks, after nearly wiping out the watchbirds, start seeking out new targets, necessitating an even more powerful machine to deal with them.

Unforeseen and unintended

Human-caused climate change is our watchbird. We tried to make the world better and easier for ourselves and, through lack of foresight, are now dealing with the significant side-effects of our previous technology advances. It’s certainly not the first time or the last. Geo-engineering, it strikes me, has the potential to be a “hawk” solution. A hasty and desperate solution to a massive problem. The danger is we don’t know what the side effects will be.  Here’s how Harvard physics professor David Keith sees it:

Consider something like an atmospheric umbrella made of airborne reflective particles, as described by David Keith in this video. It would seem to lower the average temperature if we can reflect away more sunlight. On the other hand, it wouldn’t do anything for ocean acidification, and meanwhile what other effects might this new pollutant in the air have on weather, not to mention human health? Might there be other effects we’re not thinking of? This is the basic argument against geo-engineering: Earth is a complicated bio-physico-chemical system and we’ll never know what the side-effects are until we actually do it.

Some geo-engineering may be OK

Yet again, we can’t have a knee-jerk reaction against all mitigating efforts, either. A few years ago at an educational conference, I attended a presentation by my local university’s engineering department. The presenter, an engineer and professor, took us on a survey of major leaps forward in engineering history, from the aquaducts to modern plumbing, from the keystone to modern suspension bridges. In his closing remarks, he said something like the following: “Technological progress has been seen by some as a mixed blessing, with a number of our modern problems stemming from past engineering advances. But make no mistake, we can’t just turn back the clock. If we’re going to maintain our civilization, standard of living, health, and safety, tomorrow’s solutions will involve engineering.”

By and large, this presenter was right. Even if we wanted to shun all technology and go back to subsistence farming (are you eager for that possibility, Internet readers?), the fact is our planet can’t support a population our size that way. Shunning our civilization and its technological infrastructure would bring eventual balance, at the cost of massive deaths by starvation, disease, and likely war and lawlessness as food and water became scarce.

Learn from farmers in the past

We do need to learn one thing from the subsistence farmers of our past: 100% sustainability. We have to deal with the problems of soil exhaustion, fossil fuel consumption, and water table pollution before we either run out of these finite resources or push the global climate beyond the range of human survivability. But as we wean ourselves off of the easy energy of oil and coal, and along with it the easy lifestyle of non-stop consumption, we’ll be relying on engineering solutions to transition to a sustainable energy economy. The most promising large-scale engineering projects were invented by nature: reforestation, perhaps coupled with artificial carbon sequestration.

But the main thing is to stop our emissions now, and the technology for doing that has been around for a long time. It doesn’t necessarily hurt to consider drastic counter-measures as a thought experiment. But I would suggest that damming the Mediterranean Sea or flooding Death Valley should be a very last resort.

Related stories:

Can We Geoengineer Our Climate Problems Away?

Geoengineering: Can Humans Reverse Climate Change?