I am a climate scientist, and it isn’t very often that I feel like I get to share good news with people. Luckily, every so often good things actually do happen. I have said on this site a few times before that climate science is relatively young as a field of study, and though things may feel bad at times, some of the best scientists in the world are working in the background to address our major climate issues.
Four years ago right here on Hexbear I was addressing some comrades’ concerns about climate in the long term. I told them that of course the situation we are in really is terrible, but there is one method in particular that has some real potential to majorly address our climate crisis: Silicate weathering. This method has been one of the primary methods of carbon cycle management throughout earth’s history, albeit over time periods of millions of years, and all we have to do is figure out how to apply it to human timescales. Just as I predicted, that is still indeed the most promising method of carbon sequestration, and it just took a giant leap towards viability, as outlined by the study I will be talking about with you today.
(My commentary from 4 years ago if you don’t feel like following the link)
On the, “What can be done?” side, luckily you have some of the smartest and most dedicated scientists in the world working on ways to sequester carbon, and the most promising method is accelerating the silicate weathering process which is the most effective tool to combat man made climate change.
For those who don’t want to read or don’t understand, I’ll briefly summarize why this method is important and the most likely candidate:
You may be thinking “oh let’s plant trees” which is good, sure, but consider that we are re-adding carbon which was not actively in the carbon cycle back into it. A mature forest is most times carbon neutral, as carbon output from decaying biological matter is roughly equal to carbon uptake (think about the following: how could forests continue to exist in the first place if they sucked out more carbon from the air than was added to it?)
Now think where we are getting our carbon that we add back to the atmosphere from. We pull it from underground deposits. The beauty of silicate weathering is that it incorporates carbon into rocks, and thus acts as a long term storage vessel when removing carbon from the atmosphere. The big problem though is that this process happens naturally over the course of tens of millions of years as a result of plate tectonics uplifting mountain ranges and these ranges getting weathered (as implied by the name “silicate weathering”).
So now geologists and climatologists are trying to figure out ways to massively accelerate that process, which has only become a remote possibility over the last 15 years.
How it works: 
What it means in less scientific terms:
Enhanced rock weathering (ERW) in farmland is a method to sequester atmospheric carbon on medium-long term timescales. This study measured this carbon sequestration process as a way of potentially increasing crop yields while simultaneously removing carbon from the atmosphere through the silicate weathering process. Testing this process demonstrated ann improved crop yield of 8%-18% in humid regions, plus improvements in overall soil quality. Soils with higher alkalinity sequestered the most carbon, especially in high precipitation scenarios. Expanding this study to all viable farmland across China has the potential to sequester .4gt of carbon yearly, or roughly 3% of China’s yearly CO2 emissions. Economically, utilizing this method is comparable to the cost of heavy soil modification already used for intensive agriculture. The use of ERW in nutrient poor/overly acidic soils provided a comparable effect to common agricultural practices of using lime and fertilizer to decrease acidity and raise nutrient levels. Additionally, the silicates needed to conduct this process are commonly found in waste products of advanced manufacturing and industrial processes, which could mitigate the carbon impact of manufacturing, industrial, and farming sectors while also lowering expenses in each.
Utilizing this method globally, we have the ability to improve the quality of our farmland while also removing carbon from the atmosphere at relatively fast rates, all things considered. Of course, we will still need to go carbon neutral in terms of energy production, but once that is achieved we have an actual method to remedy some of the harm we have already done to earth’s climate. Our long term climate solutions, should we use this method, are possible on a scale of decades-hundreds of years (and that’s with only our currently available technology!) as opposed to the thousands of years or longer we previously thought.
Not to be a wet blanket but the “Will it scale?” question applies as much here as it does with any other CO2 mitigation strategy. The paper’s application rate was 100 t/ha, which is an enormous amount of material to move around. There are also limits to the amount that you can safely apply because of the presence of heavy metals.
These aren’t reasons not to be enthusiastic - goodness knows working in the climate adaptation and mitigation space is a depressing grind and it’s a daily struggle to not give into hopelessness and despair. Any functional solution is better than no solution at all, but I’m leery of the “silver-bullet” style reporting that enhanced silicate weathering has attracted lately.
Silicate weathering is not perfect but in terms of long term carbon sequestration there is no match.
I said elsewhere in the comments that we aren’t going to fix our climate crisis simply by farming with silicate dust (especially without a carbon neutral society) but it certainly is a great place to start. It is especially useful to help build scale for it, but also to help build the proper research base necessary to eventually begin the process of silicate weathering for the sole purpose of carbon sequestration.
Yes, ag research in general is criminally underfunded once you strip out the relentless push to grow yields of high-intensity commodity crops, and I haven’t yet seen any reason not to include ESW as a mitigation strategy, but I think its capacity as a carbon sink is going to be lower than some of the more optimistic estimates given the logistics hurdles and physiological limits of the biological processes that operate on soils.
I do not see the agricultural sector being the actual solution, but a doorway for research to come to the actual solution.
A huge part of my motivation as a socialist is that we require a global society that values the longevity of our species and stability of the earth’s climate. A socialist society with these values would overcome our current issue of scalability because there really isn’t any better long term solution than the one that, in the opinion of most geologists and climate scientists (myself included), has historically be the strongest regulator of atmospheric CO2.
The problems associated with the actual industrialization of this process are ones that must be dealt with to solve the problem at hand, and some of the negative consequences will likely just have to be the price we pay for remedying our global impact on climate.
The actual solution here being what exactly? The reason ESW has focused on agriculture up until now is because it’s where soil weathering occurs the fastest and has some economic benefits to defray the costs of implementation. Spreading silicate dust on natural ecosystems is likely a no-go given the law of unintended consequences and the fact that sequestration rates will be significantly slower. Facilitating it using some sort of mechanical process will likely be too resource-intensive to make it worth the squeeze.
This isn’t a “force of will” problem - the processes associated with mining gigatons of basalt to implement this solution are going to be expensive, energy hungry at a time when energy is going to come at a premium, especially in terms of highly dense, easily stored and moved liquid fuels, and require expansive infrastructure that will itself consume and compete for other resource stocks. As climate change continues, it will impose increasingly severe restraints on our ability to maintain a global supply chain and there will be discussions about the tradeoffs between spending resources on this (which will reduce impacts in the future but is unlikely to have any immediate mitigatory effect) and the more immediate and pressing needs of adaptation to the climate we currently have. Even assuming we go carbon neutral and scale this up tomorrow, we’ll still have a minimum of 2 degrees of warming baked in and likely more given the increasing releases from permafrost thawing. Areas which might look like mining sacrifice zones now might be needed for farmland in the future as humanity retreats toward the poles. Writing off potential tradeoffs as a “price we’ll have to pay” is a cavalier attitude that handwaves very real issues of scale and implementation and not likely to get much traction among decisionmakers focused on meeting more immediate needs.
I do not have the energy to respond to every point you are making, but I’ll respond to the idea.
First, a carbon neutral society was half of my point. To attempt this massive operation by only burning more fossil fuels would be defeating the purpose. Second, while many of the points you are making are valid, it brings us back to what I was saying. This is a problem that will need to be solved via force of will, not because I happen to think that’s the perfect way to solve it, but because that is the reality of our current situation. It’s ironic that you call what I’m doing “handwaving” while you list off the catastrophic consequences of not solving this problem as soon as possible.
We could wait until we face starvation, war, mass migration, or societal collapse because of climate change, or we could recognize the severity of the situation for what it is and take the best appropriate action as soon as possible. If we needed a perfect solution before taking climate action, we would be better off investing our resources on inventing a Time Machine to go back and stop the first coal furnace from firing.
Other than that, you are going to need a massive chemical reaction and mass amount of energy to make addressing climate change with a long term solution possible somewhere, somehow. That is what it takes to turn that atmospheric carbon, which we derived from rock and mineral deposits, back into a similar form for long term storage. There’s no other way around it.
If we zoom out, the point of contention here is whether climate change is a problem (something that has a solution) or a predicament (something that doesn’t). I’m in the predicament camp because it doesn’t seem like we’re going to be able to pull up before we hit the wall, and so, while mitigation remains a good idea, emphasis and urgency should be on trying to minimize the consequences of global temperatures hitting (and potentially surpassing) 3 C.
I’m sensing some teleological reasoning here - you argue because we’re screwed if we don’t have a solution, there has to be one, and that because this is the best solution, it has to work. I’m not saying there might be a better solution, I’m saying there might be no solution. The catastrophic consequences are coming regardless of whether we implement this at scale. The paper you cited mentioned widespread application of basalt powder potentially sequestering 2 Gt of CO2 a year. That’s maybe enough to cover our current agricultural emissions but it’s under 1/16th of global annual emissions. Even if we do cut our carbon to 0 and still manage to implement this project (somehow under conditions of greater energy and material constraint that we have currently, given the amount of mineral resources that will be necessary to secure a green energy transition), that’s a decade and a half to undo one year’s worth of emissions, not counting CO2 release from other sources, like thawing permafrost, which will continue while we attempt to undo carbon that’s already in the atmosphere. Force of will cannot change the math on this.
In the meantime, starvation, war, and mass migration are already happening, and the mass migration part will need a substantial amount of support of it’s not going to result in tragedy. The largest mass migration of possibly any living thing in the planet’s history is about to begin and we aren’t prepared for it. Are we going to be able to afford ourselves the luxury of making sure the future isn’t quite as hot, or are we going to be forced to prioritize the present?
So, is your point just that we’re turbofucked? Is this line of reasoning productive, or is it an excuse to give up and do nothing?
I think of it like this: you’re gonna die. At some point. Probably not tomorrow. Do you use that as an excuse to do nothing or do you get up and face the day?
Humanity is headed toward a catastrophe and all signs are there’s little we can do to avert the fact that it’s going to happen. We can continue to look for solutions, and that money is definitely better spent looking for mitigation strategies than, say, weapons R&D, but, as of today, it’s peddling false hope to say that we have a way to sequester enough carbon to avoid a major disaster.
We are, however, in the privileged position to help shape what comes next. If anything, I think the techno optimistic idea that we’re a breakthrough away from fixing everything contributes more to inaction than acknowledging that we’re turbofucked.