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This study is about whether the rock weathering we’ve seen posted here before (crushed olivine etc) works in dry climates like California. The answer appears to
by vosper 3y ago
This study is about whether the rock weathering we’ve seen posted here before (crushed olivine etc) works in dry climates like California. The answer appears to be “yes, but more slowly”
> The study found the plots with crushed rock stored 0.15 tons of carbon dioxide per hectare (2.47 acres) during the study compared to plots without crushed rock. Though researchers expect different weathering rates in different environments, if this amount of carbon was removed across all California cropland, it would be equivalent to taking 350,000 cars off the road every year.
- jeffbee 3y agoTaking only 3% of California's cars off the road seems way easier.
- philipkglass 3y agoIt is, but consider the future. We need net negative emissions to stabilize the climate because we didn't decarbonize early/fast enough to achieve this goal with emissions cuts alone. The vast majority of climate progress must come from energy system decarbonization, but active carbon dioxide removal approaches like this one will be necessary to draw down the excess atmospheric CO2 accumulated so far. "IPCC Report: Carbon Removal is Now Required to Meet Climate Mitigation Targets" https://www.carbon-direct.com/insights/ipcc-report-carbon-removal-is-now-required-to-meet-climate-mitigation-targets https://www.carbon-direct.com/insights/ipcc-report-carbon-re... Also see this IPCC fact sheet about carbon dioxide removal, which includes enhanced rock weathering (the technique under discussion here): https://www.ipcc.ch/report/ar6/wg3/downloads/outreach/IPCC_AR6_WGIII_Factsheet_CDR.pdf https://www.ipcc.ch/report/ar6/wg3/downloads/outreach/IPCC_A...
- bluGill 3y agoWithout human actives the earth is slightly net negative. We need to be more net negative than that in the short term to fix some problems (ice melt), but we don't need that forever.
- vlovich123 3y ago> Without human actives the earth is slightly net negative Source? AFAIK greenhouse warming has the capacity to be a runaway effect. It's not immediately obvious that if you remove all current human carbon emissions, that temperatures would level off & start declining vs continue increasing because of the feedback loop.
- philipkglass 3y agoThe Earth slowly depletes excess atmospheric CO2 due to the geological carbon cycle of silicate weathering. This is the slow, natural counterpart of the accelerated silicate weathering discussed above. It is too slow to reverse global warming on human time scales, but it means that if anthropogenic emissions ceased Earth would reach its peak temperature in less than a thousand years (ice melting and other reactions to this change would go on for several thousands of years) and gradually decline back to the pre-industrial atmospheric CO2 and climate within about 100,000 years. My source for this recollection is David Archer's 2009 book The Long Thaw: How Humans Are Changing the Next 100,000 Years of Earth's Climate.
- unlikelymordant 3y agoHumans are currently on track for around 4 degrees of warming by 2100 assuming we hit all our current emission reduction targets (i.e. reaching net zero when governments have said they would). So removals are quite necessary.
- hedora 3y agoThey don't say how much rock they added to each field, but note that the 0.15 tons of CO2 they remove is only 300 lbs. A gallon of gasoline emits 20 lbs of CO2 when burnt. So, if they use more than 15 gallons of gasoline to mine, crush, transport and spread the rock over 2.47 acres, then this process emits more CO2 than it captures. I think they'd need to use electric high-tonnage dump trucks and electric tractors to make this process actually capture carbon. Electric tractors are stating to become available, but I don't know of any high-tonnage electric truck manufacturers.
- freeone3000 3y agoDepends on how high “high tonnage” is. Kennworth is offering a 680hp full-electric with a 3 hour range. Volvo offers an electric VNR with identical performance to its standard VNR. Freightliner sells the eCascadia, matching its regular Cascadia.
- hedora 3y agoThose are semi-trucks. You'd need to attach a compatible dump trailer to them. (Those might exist, but I don't think I've ever seen one).
- peteradio 3y agoThey exist, its how animal manures are applied to fields. Likely this would be shipped via trains long distance and last mile with semi.
- Karrot_Kream 3y agoThese vehicles would need to be charged on fully renewables or non emitting sources (like hydro) to offset this. Even if Natgas or Gas plants are much more efficient than engines, the calculation still needs to account for amortized emissions.
- freeone3000 3y agoYes? Obviously yes? Idk why everyone is assuming we’re going to keep dragging our feet on something that, at this point, is merely a matter of buying a few batteries and setting up a few more solar panels. Provinces have done it; heck, entire countries have done it. Switch to renewables already.