Before this, the only other low-budget method of planetary cooling that I knew, was dumping sulfate aerosols in the upper atmosphere (from rocket or balloon), in imitation of volcanic eruptions and dirty coal burning. The tactics have two things in common. One is that their immediate effects are regional rather than global, the other is that their effects quickly get washed out unless you keep pumping.
Carbon dioxide disperses through the atmosphere in a relatively homogeneous way. But these much larger particles will remain concentrated at particular altitudes and latitudes. So certainly when and where they are released will need to be carefully chosen.
As for the short lifespan of the particles, again it contrasts with carbon dioxide. Once a carbon dioxide excess is created, it will sit there for decades, possibly centuries. There will be turnover due to the biological carbon cycle, but a net reduction, in the form of uptake by natural carbon sinks, is a very slow process.
The carbon dioxide sits there and traps heat, and the sulfate aerosols or water droplets only alleviate this by reflecting sunlight and thus reducing the amount of energy that gets trapped. So the moment you stop launching sulfate rockets or turn off your seawater vaporizers, the full greenhouse heat will swiftly return.
That’s why extracting and sequestering atmospheric carbon is a much more permanent solution, but it is extremely energy-expensive, e.g. you can crack open certain minerals and CO2 will bond to the exposed surface, but it takes a lot of energy to mine, pulverize, and distribute enough of the resulting powder to make a difference. Some kind of nanotechnology could surely do it, but that would be a cusp-of-singularity technology anyway. So there’s a reasonable chance that some of these low-cost mitigation methods will begin to be deployed, some time before singularity puts an end to the Anthropocene.
Before this, the only other low-budget method of planetary cooling that I knew, was dumping sulfate aerosols in the upper atmosphere (from rocket or balloon), in imitation of volcanic eruptions and dirty coal burning. The tactics have two things in common. One is that their immediate effects are regional rather than global, the other is that their effects quickly get washed out unless you keep pumping.
Carbon dioxide disperses through the atmosphere in a relatively homogeneous way. But these much larger particles will remain concentrated at particular altitudes and latitudes. So certainly when and where they are released will need to be carefully chosen.
As for the short lifespan of the particles, again it contrasts with carbon dioxide. Once a carbon dioxide excess is created, it will sit there for decades, possibly centuries. There will be turnover due to the biological carbon cycle, but a net reduction, in the form of uptake by natural carbon sinks, is a very slow process.
The carbon dioxide sits there and traps heat, and the sulfate aerosols or water droplets only alleviate this by reflecting sunlight and thus reducing the amount of energy that gets trapped. So the moment you stop launching sulfate rockets or turn off your seawater vaporizers, the full greenhouse heat will swiftly return.
That’s why extracting and sequestering atmospheric carbon is a much more permanent solution, but it is extremely energy-expensive, e.g. you can crack open certain minerals and CO2 will bond to the exposed surface, but it takes a lot of energy to mine, pulverize, and distribute enough of the resulting powder to make a difference. Some kind of nanotechnology could surely do it, but that would be a cusp-of-singularity technology anyway. So there’s a reasonable chance that some of these low-cost mitigation methods will begin to be deployed, some time before singularity puts an end to the Anthropocene.
The need for ongoing maintenance is a feature not a bug given that we don’t understand the actual effects in high resolution.