Op-Ed: Harvard/Yale study — ‘Dim’ the sun to fight global warming

Posted Nov 25, 2018 by Paul Wallis
An ambitious, not to say mindboggling, idea to dim the sun with aerosols has received a mixed reception from scientists. The idea is based on spraying sulphates from an airborne delivery system.
Shanghai  like many other Chinese cities  depends on surface water that is heavily polluted  such as...
Shanghai, like many other Chinese cities, depends on surface water that is heavily polluted, such as the Huangpu River shown here whose water comes through Suzhou Creek from the heavily polluted Lake Tai.
Jakub Halan (CC BY-SA 3.0)
The study is based on the principles of “solar economics”, or managing sunlight for economic purposes. Available information consists of the Environmental Research Letters page on the IOP Science website. The information doesn’t mince words about the possible difficulties, and focuses on practical issues related to delivering the sulphates, which would be required in huge quantities.
Responses have been mixed, from basic info covering skeptical reactions, to less impressed commentary describing the idea as a band aid for the global warming problem. Comments include the somewhat trite observation that excess CO2 will take hundreds of thousands of years to dissipate.
(So it will, if you don’t do something about CO2 scrubbing. What, nobody can think of a use for the 16 billion tons of CO2 released annually? What are you guys doing for a living, keeping the furniture company? It looks like it.)
Overall the criticisms fall in to the usual quasi-comatose, status quo-worshipping category. Another response is that an obscure movie called Snowpiercer, about the survivors of humanity trapped on a global train in an artificially induced ice ages, will become a reality. This is at the other, typical internet, end of the spectrum of responses, imbecilic at best. On that basis nothing would have been done about chlorofluorocarbons, either.
These passive and rather myopic reactions leave a few things to be desired themselves, and it’s hard to say that the dimming idea is being taken seriously. In short, it looks like another idea being dismissed out of hand.
A different perspective of practical scale needs
The Harvard and Yale study doesn’t understate the difficulties of the aerosol proposal. In fact, it makes it clear that the problems are many, and require heavy duty logistics. The criticisms are missing the point to a very wide degree. The most significant part of the study is discussing a possible working method of managing solar heat input in to the Earth’s atmosphere. That’s important.
There may be other, more deliverable, options using different compounds, for example. (Natural sulphates present in the atmosphere are one of the basic mechanisms for cooling. No mystery there, but would something else achieve the same result, with better and less demanding delivery systems?) There may be a way of creating a manageable self-sustaining chemical or other coverage of the Earth to deal with solar heat.
Another, much ignored, issue which should have been raised as both a positive and as a criticism is the sheer scale of this proposal. The idea of having working mechanisms on a scale able to deal with human-created global problems is being almost completely ignored. Existing organizational capacities are largely local or regional, on far too small a scale, and would need multiple participants to work at all. This configuration of resources means a great many cooks for the same dish. That’s not a great framework for decision making, managing initiatives, or practical applications.
That issue alone makes this proposal a must-explore. There’s no harm in thinking it through, and looking at all the options in a properly coordinated way. The half ass, half witted responses to global catastrophes have been inept to say the least, poorly coordinated, and produced far more rhetoric than results.
Can it work?
In theory, yes. You might achieve something by turning every roof on earth in to a white spectrum reflection, too, but something has to be done, and this at least has the benefit of working on the basis of a known cooling principle. Other methods of delivery, like a simple airborne feed from static sites, might work. The main risk is that nobody will look at options. An aircraft delivery system, as proposed, may entail a long logistics tail, where as a solar powered drone could be a fire and forget option.
There are way too many things to be pondered for an easy answer to the solar dimming proposal. The trouble is that the word “impossible” is useless in terms of the sheer magnitude of these global problems. The certainty, and the risk, is that if you don’t explore these big ideas, you may miss the beginnings of a working solution.