Elliot Chang

@blueicehiggins Hey John, I hear these points and agree with your back-of-envelope calculations. Have you communicated with @Isometric_HQ @PuroCO2Removal or @CascadeClimate on your concerns? We need your experienced advice and wisdom here more than ever.

Let's talk about 'enhanced' 🪨 weathering (ERW) and strategies (that are published) for monitoring, reporting, and verification of CO2 removal. ERW is one of the current 🔥 places to stick CO2 for a low low (or at least reasonable) 💰. For the 📰- I am all in favor of stopping 🌎🌡️ and think that moving away from 🦖⛽️ as fast as possible is the way to go. I'm also 😎 with CO2 removal if its cheap and robust. But as someone who as spent a lot of ⏳🤔 about the processes that move CO2 through the 🌎 system, I think it's gonna be hard! A 🧵1/4

@blueicehiggins @_david_ho_ You’re right, John, that we observe much retardation of the released weathering products even within the soil profile. We’re working to define how these net subprocesses (adsorption, inclusions, co-precipitation) limit ERW efficacy and on what timescales.

Except what they don't want to talk about is the alkalinity that's likely removed in clay minerals somewhere along the way! With all of the Si and other things you produce from ERW of silicates, you're also not even safe once you get to the 🌊! Turns out that all those hot spots for chemical weathering are also hot spots for clay formation! agupubs.onlinelibrary.wiley.com/doi/10.1002/20…

I think people working on enhance rock weathering (ERW) know it’s a marine CO₂ removal (mCDR) technique but the ocean people don’t know it yet.

AGU attendees (and other SF-based individuals working in carbon sequestration tech), Funga and Eion are hosting a CDR Happy Hour following the AGU session “Science-Based Gigaton-Scale Carbon Dioxide Removal” on Thursday afternoon. We hope you'll join us! eventbrite.com/e/cdr-happy-ho…

@Jeffinerca @allegra_mayer @carbon_180 Sensed the audience wasn’t in fear or shock, but rather intrigued by the concept of buying CDR and also incorporating policy-driven practice changes (Buy-and-Rent vs either/or). Allegra’s poster at Goldschmidt Lyon ‘23 was a great pitch for this!

Ok, I did it. In front of a roomful of #CDR enthusiasts, i admitted that I don’t believe in only 1000yr durability. Even 20yrs helps—as long as we keep applying a practice, in new locales. Full credit to @allegra_mayer And thanks @carbon_180 for a great mtg!

@_neilhacker Enjoy coffee at a local park in the morning, watch an English premier league game at a pub, treat yourself to nice groceries (Grand Central Market!), cook a nice impromptu dinner for a friend :-)

Best things to do on a Sunday with no plans in NYC?

@anupama_khan @FECMgov @MICleanEnergyRD @CEM14_MI8 By extension, open and collaboratively developed protocols with proper incentives in monitoring. In ERW this includes methods to replicate field trial procedures across various geo-climatic regions.

@FECMgov @MICleanEnergyRD @CEM14_MI8 What are the biggest collaborative opportunities in MRV? Open data seems like it could be a big one, for deployments across geographies/climate zones.

Last week, #FECM’s Mark Ackiewicz & Michael Thompson discussed measurement, reporting, & verification (#MRV) for carbon dioxide removal (#CDR) at the @MICleanEnergyRD event at @CEM14_MI8 in Goa, India. The discussion highlighted opportunities to advance MRV through collaboration.

@mati_carbon Congrats on the public announcement, @mati_carbon. Good to see another colleague in the ERW space.

@Jeffinerca See you in Lyon if it’s for Goldschmidt!

Perth, Edinburgh, Aberdeen, Lyon, Poitiers, Paris, South Hadley… “It will be more efficient that way” (what the hell was I thinking!!)

@PeterOlivier Appreciate this. We must also keep in mind the impact on MRV in the soil as geochemistry does change when mixing silicates+biochar.

I often get asked about combining applications of biochar and enhanced rock weathering to improve crop yields. It's a good idea that's hard to execute at the moment - so if you've wondered "why aren't we doing this already?" here is my take:

@WillKnapp18 Congrats on this work, Will. Appreciate the insights into subprocesses beyond the field.

Check out our latest paper in ES&T. We take a granular approach to quantify the secondary processes that impact carbon removal downstream of an enhanced rock weathering site. Measuring cation loss from feedstocks on the field isn't enough! pubs.acs.org/doi/10.1021/ac…

@PeterOlivier Congrats, Pete. Lots of work to do, and we all need the financing to move rock and measure CDR.

tldr: money for rocks, rocks for climate long: we're going to use two of humanity's core competencies, 1) crushing rocks and 2) farming, to scale CDR and drive benefits from the carbon market into rural communities and food systems. it's early, and promising; lots of work ahead.

@dpaessler @RobertHoglund @carbon_drawdown @RSteffanides @JensHammes @IngridSmet_geo If all methods point to No CDR, that’s also a result to be thoughtful of!

I am personally convinced that assessing cdr effects via CO2 measurements using lots of electronic sensors 24/7/365 is a simpler approach than trying to understand the huge signal noise of the armada of interconnected processes in the soil with their proxy metrics AND it gives us a much faster signal. „Fast“ may be the most important keyword here since we need to understand quickly what rock works on what soil, or not. We don‘t have years for each iteration of the necessary long chain of erw experiments. But first we need to demonstrate that data from the soil gas CO2 based method converges with other approaches. Our greenhouse experiment with 15 soils combined with 11 rocks in 350 pots should enable us to show the convergence.

Here is our detailed report about our attempts to measure the speed of enhanced rock weathering on croplands in four extensive field-experiments over more than two years. The traditional leachate- and EC/pH-based MRV approaches have not shown any signal (yet!). But by measuring the basalt's dissolution rate and especially by measuring CO₂ in the soil gas we seem to be able to assess the CDR effect as early as weeks or months after basalt application. In the future, this novel approach could provide a faster way to assess the effectiveness of ERW in removing CO₂ from the atmosphere. carbon-drawdown.de/blog/2023-5-17…

@dpaessler @RobertHoglund @carbon_drawdown @RSteffanides @JensHammes @IngridSmet_geo Such uncertainties may cause certain MRV approaches to not show statistically significant CDR between test and control systems. This should be considered limitations of the measurement approach.

@dpaessler @RobertHoglund @carbon_drawdown @RSteffanides @JensHammes @IngridSmet_geo Thanks for your thoughts and research, Dirk. Each MRV approach has measurement artifacts that impact comparability to a certain extent. Gas/liquid/solid in theory should reconcile each other, but one approach may have greater uncertainty over another.

@liuhenry @carbon_drawdown @RobertHoglund @GreenOlivine @dpaessler @RSteffanides @JensHammes @IngridSmet_geo @LithosCarbon Agreed. Export of weathering products that also address other losses (plant uptake, secondary mineral formation and sorption retardation, and strong acid anion fluxes) should align with other “reservoir” MRV methods. Each approach though has measurement-based artifacts…

@carbon_drawdown @RobertHoglund @GreenOlivine @dpaessler @RSteffanides @JensHammes @IngridSmet_geo @LithosCarbon An interesting note is that our measurements also account for sorption within the sampled portion of the soil profile. So the signal here means not just dissolution of the applied rock but also *export of cations*.

Soil microbes that immobilize REEs! Inspiration for our company’s soil fingerprinting concept @EionCarbon doi.org/10.1111/1758-2…

@SFClimateWeek starts tomorrow! Can't wait to represent @EionCarbon with thought leaders in academia, policy, and industry.

@Jeffinerca I’m sorry for your loss, JP. I hope Toffee’s binkies will live on in your memory for a long, long time.

We’ve loved all our bunnies… but Toffee was the fluffiest and our favorite. Rest in peace little one.

Great postdoc years, @Livermore_Lab and @BerkeleyLab! Shoutout to @Seaborg_LLNL for the training and fun times. Onward at @EionCarbon - making our mark in the fight against climate change👊