Phosphorous and Carbon Sinks – And no, Carbon Sinks don’t make for dirty dishes

I’m planning to live for quite a bit longer, so one of the things I’m concerned about is global warming caused by increasing amounts of Carbon Dioxide in the air. I mean, it is going to be very difficult to enjoy my retirement inside a hermetically sealed bubble if the only thing they show on the news at night is pictures of people dying from environmental disasters in less fashionable nations. After seeing images of people dying of heatstroke in Amazon desert, the only thing that would probably make me feel better is to crank up my air conditioning and sip iced pina colada.

As a result, I’ve gotten to thinking about if it would be possible to increase the amount of carbon taken up from the atmosphere by scattering phosphorous rich gravel over certain parts of Australia to encourage plant growth. Since the vast majority of Australian soils are phosphorous poor, a lack of phosphorous is often a limiting factor in the growth of plants. Once the gravel had been scattered it would slowly weather away, gradually releasing phosphorous over many years. However, spreading this gravel could be quite expensive. To add an average of one gram of phosphorous rich rock per square meter to an area the size of Tasmania (that little island just below the right half of mainland Australia) would require about 70,000 tons of rock. That’s equal to a cubic chunk of rock about 12 stories high. Finding that much rock isn’t going to be a problem, but grinding it up and scattering it is. Normally adding phosphorous to land for agricultural purposes doesn’t involve flinging gravel. Perhaps some sort of catapult could be used?

Besides absorbing carbon and reducing the effect of global warming, there could be other benefits, including improved soil and water quality, and increased plant growth could help moderate the extremes of Australian climate.

If this idea is practical at all then it is only likely to work in areas with local sources of phosphorous and access to cheap catapults. However, if property owners could receive payments for increasing the amount of carbon their land holds, then they could try whatever method they think is best for their location.