Let’s see, what would we make those nano-disks out of? He says (see PNAS paper below):
Silica-alumina ceramic hollow microspheres with diameters of 1 μm. (aka 1 micron)
The micron-sized silica dust, which is ingested through the normal breathing process, coats the inner lining of the lungs (alveoli) and forms fibrous scar tissue that reduces the lungs’ ability to extract oxygen from the air.
Respirable particles, which are less than 10 microns in diameter, are invisible to the naked eye. They travel through the respiratory system, eventually depositing themselves in the air sacs (alveoli).
I’ll give him points though for saying geoengineering is “inherently imperfect”, but I think his “cure” is worse than the “disease”. Just have a look at the material safety data sheet (MSDS) for the 3M Zeeospheres he’s proposing (see link below) and you’ll see what I mean.
Stopping global warming
There may be better ways to engineer the planet’s climate if needed to prevent dangerous global warming than mimicking volcanoes, a University of Calgary climate scientist says in two new studies.
Releasing engineered nano-sized disks or sulphuric acid, a condensable vapour, above the Earth are two novel approaches that offer advantages over simply putting sulphur dioxide gas into the atmosphere, says Dr. David Keith, a director in the Institute for Sustainable Energy, Environment and Economy and a Schulich School of Engineering professor.
Geoengineering, or engineering the climate on a global scale, “is inherently imperfect,” says Keith, who is in the vanguard of scientists worldwide investigating the topic.
“It cannot offset the risks that come from increased carbon dioxide in the atmosphere,” he says. “If we don’t halt man-made CO2 emissions, no amount of climate engineering can eliminate the problems—massive emissions reductions are still necessary.”
Keith suggests two novel geoengineering approaches—‘levitating’ engineered nano-particles and the airborne release of sulphuric acid—in two newly published studies, one he solely authored and the other with scientists in Canada, the U.S. and Switzerland.
Scientists investigating geoengineering have so far looked mainly at injecting sulphur dioxide into the upper atmosphere. This approach imitates the way volcanoes create sulphuric acid aerosols, or sulphates, that will reflect solar radiation back into space—thereby cooling the planet’s surface.
One advantage of using sulphates is that scientists have some understanding of their effects in the atmosphere because of emissions from volcanoes such as Mt. Pinatubo, Keith says.
“A downside of both these new ideas is they would do something that nature has never seen before. It’s easier to think of new ideas than to understand their effectiveness and environmental risks.”
In his study in the Proceedings of the National Academic of Sciences, a top-ranked international science journal, Keith describes a new class of engineered nano-particles that might be used to offset global warming more efficiently and with fewer negative side-effects than using sulphates.
In a separate new study published in the journal Geophysical Research Letters, Keith and international scientists describe another geoengineering approach that may also offer advantages over injecting sulphur dioxide gas.
Releasing sulphuric acid, or another condensable vapour, from aircraft would give better control of particle size, thereby reflecting more solar radiation back into space while using fewer particles overall and reducing unwanted heating in the lower stratosphere, they say.
I’ve located the PNAS article here:
here’s the section on “nanodisks”
The Cost of Engineered Particles. Is it possible to fabricate such particles at sufficiently low cost? Any definitive answer would, of course, require a sustained broad-based research effort. The following argument serves only to suggest that one cannot discount the possibility: Approximately 10^9 kg of engineered particles similar to the example described above would need to be deployed to offset the radiative effect of CO2 doubling.
Assuming a lifetime of 10 years, the particles must be supplied at a rate of 10^8 kg∕yr. A plausible upper bound on the acceptable cost of manufacture can be gained by noting that the monetized cost of climate impacts and similarly the cost of substantial reductions in greenhouse gas (GHG) emissions are both of order 1% of global gross domestic product (GDP) (28). Suppose one demanded that the annualized cost of particle manufacture be less than 1% of the cost of abating emissions, that is 10−4 of the ∼60 × 1012 global GDP.
Under these assumptions, the allowable manufacturing cost is 60∕kg. Many nanoscale particles are currently manufactured at costs significantly less than this threshold.
Silica-alumina ceramic hollow microspheres with diameters of 1 μm (e.g., 3M Zeeospheres) can be purchased in bulk at costs less than 0.3∕kg. Moreover, bulk vapor-phase deposition methods exist to produce monolayer coatings on fine particles, and there are rapid advances in self-assembly of nanostructures that might be applicable to bulk production of engineered aerosols.
10^9 kg is one billion kilograms, or 1,102,311 short tons. I don’t have figures on how much silicon dust makes it into the air globally, but 1.1 million tons of silica nanospheres seems a bit hard to come by for a process. Cost may not be the biggest issue. Deployment and potential health effects are much bigger considerations.
Here’s the company website: http://www.zeeospheres.com/
Do I want these in the free air? Heck no.