Alkalinity sourcing challenge
Applications due January 6, 2025About the challenge
In total, the world needs to do ~1 teraton of carbon removal over the next ~100 years to effectively stabilize global temperatures around 1.5°C, in addition to reducing emissions. If we wanted to turn back the clock to pre-industrial temperatures, we’d need to do an additional ~2 teratons of carbon removal on top of that.
Frontier supports a portfolio of promising approaches that could potentially reach this collective scale. This challenge focuses on a subset of those approaches that rely on alkalinity as feedstock.
To that end, we’re interested in finding the most accessible deposits of highly reactive rock that could collectively get the world to teraton scale CDR over the next century at the cheapest possible cost. In practice, this means we’re interested in locating the most accessible deposits of highly reactive rock, in the fewest possible sites.
For this challenge, we are focusing on minerals that have sub-decadal reactivity rates in ambient air, like naturally occurring brucite, portlandite, magnesia, wollastonite, etc (olivine alone does not qualify, please see our FAQ for explanation). While the location and extent of these mineral resources is unknown, there are known geological processes through which large deposits of these minerals, particularly brucite, can form. With this challenge we’re looking to crowdsource hypotheses for sites that could sum up to enough alkalinity to give the world a shot at at least 1 teraton of alkalinity-driven carbon removal.
Prompt and application instructions
Please write a “Site Hypothesis” describing a geological site where you hypothesize there to be a sizeable deposit of a fast weathering mineral.
What we’re looking for:
- Highly reactive minerals: We anticipate most submissions to be for brucite-rich rock - Mg(OH)₂ - or rocks composed of brucite with other fast-reacting minerals. Other mineral(s) are acceptable but should be at least as reactive as brucite with carbon dioxide (i.e., 100 um particles in ambient air would weather fully within 10 years). If you’re proposing minerals other than brucite, please provide supporting evidence of reaction kinetics in your write-up. Some examples of minerals of interest may include portlandite, chrysotile, periclase (MgO), or wollastonite.
- High grades of that mineral: Deposit at the site must have at least 10Gt of the mineral(s) at >30% grade, where grade is defined as the percent of the ore by mass that is comprised of reactive mineral(s)
- Relatively compact geography: “Site” is defined as a rock formation / geological feature, generally <500 km2 in area and similar in geological make-up throughout its extent.
- Please see the example we give in the FAQ, note that this specific example is ineligible for award consideration. We’ve also provided a few ideas for inspiration, also in the FAQ.
A Site Hypothesis should be a written document approximately 2-5 pages long containing the following components:
- Description of the site including name, location, relevant geologic history
- Your reasons for believing there is a large deposit of brucite (or similar mineral) at this site
- Any supporting data from the literature or your own work
Please submit your Site Hypothesis in .doc or PDF form to alkalinity-research@frontierclimate.com. The deadline for submission is 5pm on January 6, 2025. We may email you with questions about your submission over the following few weeks. Winners will be selected by the end of January.
Award
$5,000We will award $5K honoraria to the 10 best submissions that meet the criteria in the instructions above. Submissions will be judged by Frontier in conjunction with expert academic reviewers. If more than 10 submissions meet the above criteria, awards will be given to the largest deposits with the strongest theoretical and empirical evidence provided in support.
We understand the possibility that there are no sites in the world that meet our criteria, which would make this task impossible. As a result, it is a possibility that we receive no submissions or that none of the submissions meet the bar specified above.
FAQ
What’s an example submission?
An example site is the New Idria complex in California, which likely has >700 Gt of CDR potential based on published mineralogy (brucite and chrysotile) characterizing the serpentinized rock. New Idria is ineligible for this challenge.
What are some other ideas that could serve as inspiration for applicants?
While much of the known brucite/portlandite arises through serpentinization and hydrothermal alteration, these processes necessarily produce lower grades of brucite. However, it has also been documented that brucite can form in an aureole surrounding a magmatic intrusion into carbonate rock. These formations are not well-documented but have the potential to be very high grade brucite. An example submission might suggest a known site of a large magma intrusion into carbonates, even if that site has not been specifically characterized for its brucite content in the literature. The write up would include experimental or theoretical evidence about the size of the magma intrusion and resulting estimates of aureole size that exceeds 10 Gt of reactivity (e.g. 20 Gt of 50% grade ore or 12.5 Gt of 80% grade ore).
While serpentinization typically produces brucite at <25% grade, there may be sites in which unique conditions caused extensive serpentinization plus hydrothermal alteration, enabling the grade of brucite to exceed 50%. Experimental or theoretical evidence in support of the high grade material would need to be included in this submission.
Wollastonite has very fast weathering rates, but the distribution and size of known deposits is quite limited. A submission could detail a site where the geological history is likely to have produced wollastonite at high grades, even if no experimental evidence has been acquired.
Komatiites have high magnesium content. Evidence of very large komatiites with reactive magnesium minerals could make for an interesting submission.
What is the definition of a “site”?
“Site” is defined as a geological deposit or locality, generally <500 km2 and similar in geological make-up throughout its extent. If helpful to support your argument for your proposed site, feel free to explain how you chose to define the site boundaries in your submission. Your site can be located anywhere in the world.
Why aren’t sites with only olivine eligible?
While silicates like peridotites (olivine/dunite) and basalt have been proposed for carbon removal previously, most silicates would require >30 years to react with silicates in ambient air at reasonable particle sizes. For this research project, we are interested in quantifying the carbon removal capacity of faster weathering minerals. An exception is wollastonite which is reported to weather much faster than olivine.
Will submissions be shared publicly?
No. Entrant names, affiliations, and content of submissions will be kept confidential to the Frontier team and reviewers. Submissions will only be shared with 1-2 academic reviewers who are under NDA with Frontier and are unaffiliated with any CDR companies. Frontier will not announce the challenge results publicly. Award recipients are welcome to share their own work publicly if they’d like.
Can I submit multiple proposals?
Yes!
Can I stay involved in this research project after submitting a Site Hypothesis?
Yes! Please indicate your interest areas (and feel free to share more about yourself) at the end of your submission document.
Who is eligible to apply?
Anyone is eligible! No credentials are required. Students, post-docs, principal investigators, geology enthusiasts are all welcome!
How will the award be given?
Participants will be contacted with results and next steps the week of January 20th.