Stories
Slash Boxes
Comments

SoylentNews is people

posted by chromas on Friday July 17 2020, @06:55AM   Printer-friendly
from the dust-bowl dept.

Spreading rock dust on farms could be a major climate action:

Eventually (ideally sooner rather than later), efforts to reduce greenhouse gas emissions are going to have to be joined by a technology that actively removes CO2 from the atmosphere. There are a number of options [...] and a new feasibility study suggests that one of them—spreading crushed rock on farm fields—deserves serious consideration.

[...] Using crushed rocks isn't a new idea. Some common minerals react with water and CO2 as they weather, converting CO2 from the air into bicarbonate dissolved in water. That bicarbonate (along with some calcium and magnesium) may hang out in groundwater or make its way into the ocean. And along the way, it can also turn into solid carbonate. Whatever route it takes, it's no longer a greenhouse gas in the air.

Over hundreds of thousands or millions of years, this process has an important stabilizing influence on Earth's climate. Warmer climates encourage more weathering, pulling greenhouse gas out of the atmosphere.

[...] One way to accelerate weathering is to grind up that rock into small particles. Just as powdered sugar dissolves in water much more quickly than a large solid candy would, these small particles will weather much faster. Spreading that crushed rock over farm fields not only nicely exposes it to the elements but can also be beneficial for the soil, replenishing nutrients and counteracting pH changes in heavily farmed soils.

[...] Globally, the researchers estimate that this process could be used to capture 500 million to 2 billion tons of CO2 per year in 2050. For comparison, scenarios that limit global warming to 2°C generally involve capturing something like 2 to 10 billion tons per year in a few decades from now.

[...] In the US, EU, and Canada, the researchers estimate that all this would cost about $160 to 190 per ton of CO2 captured, while China, India, and Brazil could do it for $55 to 120 per ton. That's in the same ballpark as other some options for atmospheric CO2 removal..

Journal Reference:
David J. Beerling, Euripides P. Kantzas, Mark R. Lomas, et al. Potential for large-scale CO 2 removal via enhanced rock weathering with croplands, Nature (DOI: 10.1038/s41586-020-2448-9)

Additional Information:
Johannes Lehmann, Angela Possinger. Removal of atmospheric CO2 by rock weathering holds promise for mitigating climate change, Nature (DOI: 10.1038/d41586-020-01965-7)


Original Submission

 
This discussion has been archived. No new comments can be posted.
Display Options Threshold/Breakthrough Mark All as Read Mark All as Unread
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
  • (Score: 0) by Anonymous Coward on Saturday July 18 2020, @04:16PM

    by Anonymous Coward on Saturday July 18 2020, @04:16PM (#1023407)

    Precisely, ideas like this might be a part of the solution once we're operating at a net negative emissions level to put us back where we were at the beginning of the century. In essence speeding up the cooling process. But, by lightening areas that had been darker, you're not really doing much to get snow back where it belongs. That is the glaciers and the polls. It would be more effective to make those lighter.

    Unfortunately, that makes the problem of energy generation to complete the problem even larger as the untold tons of rock dust needed would need zero or extremely low carbon emission energy sources to not cancel out the effect.

    In the long run, it's probably going to be a patchwork of these sorts of ideas on top of drastically cutting our emissions that works. Unfortunately, I don't see that happening quickly enough to stave off the worst of it. And even if we magically hit slightly negative emissions right now, we've already lost a ton of wildlife that will take centuries or longer to recover the biodiversity to handle future climate problems.