2. Enhanced Weathering using Cropland
Details of this are given on the Comings Foundation web site. See the NET (Negative Emissions Technology) section. In essence it involves spreading pulverized basalt, a type of silicon rock, on large areas of cropland. These rocks are rapidly weatherized, a process that involves the sequestration of atmospheric CO2 into a mineralized form which is deposited on the cropland. This results in the removal of CO2 from the atmosphere and the silicon enrichment of the soil, improving crop yields and stress resistance. The products of weathering eventually reach the ocean and combat ocean acidification. In addition, this process decreases the production of N20 from the soil. N2O is also a greenhouse gas which warms the atmosphere 300 times more effectively than a comparable amount of CO2.
When compared to other NET approaches enhanced weathering on cropland has several advantages:
• It solves the problem of how to safely store the captured CO
2. Most other NETs struggle with this issue.
• It helps to decrease ocean acidification.
• It does not compete with regular croplands.
• In fact, it improves existing croplands.
• It replaces leached out silicon improving plant resistance and yields.
• It increases the pH (makes more alkaline) of soil.
• It decreases the soil production of N
20, a greenhouse gas 300 times more powerful than CO2.
• With caveats, it is cheaper than most other NETs.
• Farmers already spread lime on their crops. Lime, however, releases CO
2 to the atmosphere. Simply substituting basalt would use the same equipment used for lime, prevent putting CO2 into the atmosphere, and enrich the croplands with silicon.
• It avoids the significant restrictions of regulatory groups compared, for example, to ocean fertilization and SRM (solar radiation management). It can be governed locally (bottom up) instead of globally (top down).
• If paired with solar, wind or other carbon negative energy sources and using silicate wastes from industry, it eliminates the issue of the cost of grinding and mining.

This NET approach raises some a number of questions. We would provide grant funds to obtain the answers. These questions include:
a) There are many types of basalt. Which ones would be the best?
b) Where in the US can they be mined?
c) Where are stockpiles of aggregate waste basalt that can be used?
d) As stated by Beerling et al (2020) national inventories of the location, availability and extent of this resource are required to assess the potential contribution of this resource to CDR via ERW. Need to develop a US inventory.
e) Where are the stockpiles of waste silicates from mining?
f) How much would cost per ton CO
2 be if solar or wind energy was used for grinding?
g) Would carbon free sources of energy (solar, wind) be available
in these areas?
h) What is the cost of mining, grinding and distribution?
i) How much would cost per ton CO
2 be if solar or wind energy was used for grinding?
j) What is the weathering rate of finely ground basalt?
k) How to get farmers to switch from lime to basalt?
l) Can we use the same companies that distribute lime to
distribute crushed basalt?
m) What are the governing issues, if any?
n) What are the prospects and mechanisms of spreading this
technology to other countries?
o) Long term ERW studies are needed (Beerling, et al 2020).
We would also ask researchers to set up moderate sized plots of land, grow various crops on that land, spread both pulverized basalt and pulverized olivine and follow up to determine what chemicals are released, what chemicals are taken up by the plants, the weathering rate, and the effects on crop yield. In relation to olivine does it result in unacceptable levels of chromium, or other toxic metals in the crops?
Three of the co-authors of the Beerling et al paper, Stephen P. Long, Evan DeLucia and Ilsa Kantola were from the Carl R. Woese Institute for Genomic Biology and/or the Department of Plant Biology, both at the University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. (which happens to be where I took my undergraduate work) We could offer them grant funds to study the above questions.

For further details see
-> 2. Negative Emission Technology
-> C. Enhanced Weathering