Cooling the Earth by injecting sun-blocking particles into the stratosphere could be “remarkably inexpensive”, according to the most detailed engineering analysis to date….
The new research estimated the technology costs of putting millions of tonnes of sulphate particles high into the atmosphere. This form of geoengineering mimics major volcanic eruptions, which have significantly reduced global temperatures in the past.
“We show that a hypothetical deployment programme, while both highly uncertain and ambitious, would be technically possible,” said Gernot Wagner from Harvard University. “It would also be remarkably inexpensive, at an average of around $2bn to $2.5bn per year.” About $500bn (£388bn) a year is currently invested in green technologies.
The idea of geoengineering is controversial, with opponents arguing it could seem like an easy solution to global warming and weaken efforts to cut the root cause of emissions. Others warn it risks serious unintended consequences, such as droughts and damage to crops. In October, more than 100 civil society groups condemned geoengineering as “dangerous, unnecessary and unjust”.
If this sort of thing sounds frightening and dystopian, that’s because it is. The consequences of such an effort would be unpredictable and almost certainly devastating in myriad ways for both humans and wildlife. And it wouldn’t address the myriad other consequences of CO2 buildup, including ocean acidification and other problems.
Of course, scientists are trying to come up with bizarre geoengineering projects to deal with those as well, including dumping enormous amounts of iron filings into the ocean. Not kidding.
Realistically, minor geoengineering projects will likely be part of the comprehensive answer to climate change. But every one of these “solutions” to the problem either addresses only specific symptoms of the broader disease or is logistically unworkable, outrageously expensive, and carries enormous unintended negative consequences.
Most frustratingly, staving off devastating climate impacts is already technologically and economically feasible. Developing countries can continue to grow their economies by skipping over fossil-fuel stages in technical advancement, while the developed world can use their significant GDPs to implement “Green New Deal” programs that create jobs and build new infrastructure. For instance, it is already cheaper to build new wind farms than continue to operate coal-fired plants.
To use a medical analogy, it is far easier and safer to implement a regimen of healthy diet and exercise after years of neglect than to stage increasingly dangerous medical interventions to deal with diabetes, heart disease, and other obesity-related illnesses while continuing to practice an unhealthy lifestyle. Ironically, of course, conservatives refuse to demand the same level of responsibility vis-a-vis protecting our planet as they do from individuals in their personal and financial lives. Geoengineering is the climate equivalent of magic Fen-Phen diet pills.
Just as with medical interventions and many pharmaceutical drugs, geoengineering has side effects that in turn will require their own counter-interventions. As Brad Plumer noted in the Washington Post, once you start geoengineering it’s really hard to stop.
But there’s one other concern we didn’t really touch on in that interview: Once the world startsgeoengineering, we can’t really ever stop — especially if everyone keeps pumping carbon-dioxide into the atmosphere at the same time. Why? Because as soon as we quit spraying those reflective particles into the atmosphere, the Earth will heat up very, very, very rapidly. And sudden climate change is even worse than the kind we already know about.
David Appell points to a recent study in the Journal of Geophysical Research that highlights this point vividly. The authors first used 11 climate models to forecast what would happen if the world used solar geoengineering to offset a 1 percent annual rise in global carbon-dioxide emissions. The good news: Global temperatures stay pretty stable. But then they stopped the geoengineering. And that was catastrophic: Global temperatures spiked very sharply.
This means that, at best, this sort of thing would only be feasible for a short window while the world rapidly moves to negative CO2 emissions anyway. There remains no substitute for weaning ourselves from fossil fuels.
But the fact that serious scientists are even considering these approaches demonstrates how serious and catastrophic the threat is.
Dealing with climate change in a responsible way is our most urgent policy challenge today. We can’t count on silver bullets to save us.